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Biomedical subjects

N Watanabe

Publications and source records attributed to N Watanabe.

At least 991 records · Page 55Linked to original sources
PubMed1988

Peripheral embolization provides evidence for microvascular collaterals in hearts with chronic coronary artery occlusion.

Macroscopic collateral vessels are widely regarded as the primary source of blood flow to collateral-dependent myocardium. Microscopic coronary collateral vessels have also been described, but their functional significance is controversial. Experiments were conducted in 18 anesthetized dogs with chronic coronary artery occlusions. Indices of collateral function demonstrated that all hearts were well-collateralized. The previously occluded coronary artery was cannulated distal to the obstruction for measuring retrograde flow before and after injection of either 13 microns or 84 microns emboli. Mean arterial pressure and heart rate were not altered by coronary embolization. Embolization with 13 micron spheres caused retrograde flow to increase by 43% (n = 11), whereas embolization with 84 micron spheres had no effect on retrograde flow (n = 7). Retrograde flow dislodged occlusive 84 micron spheres, since these spheres were found in the retrograde flow, and since antegrade flow increased by 250% after retrograde flow diversion. These findings demonstrate that collateral vessels less than 84 micron diameter contribute significantly to perfusion of chronically collateral-dependent myocardium.

Animals↗
PubMed1988

Studies on murine IgE with monoclonal antibodies. I. Characterization of rat monoclonal anti-IgE antibodies and the use of these antibodies for determinations of serum IgE levels and for anaphylactic reactions.

Rat monoclonal antibodies were constructed by fusion of immunized rat spleen cells with a nonsecreting mouse myeloma cell. Two monoclonal antibodies (6HD5 and HMK-12) were selected for further study. Both reacted with various IgE molecules of different specificities and different allotypes, but did not react with immunoglobulins of other isotypes and with light chains. These antibodies were therefore anti-isotypic (IgE) and not anti-allotypic or anti-idiotypic. It was shown by competition studies that these antibodies recognize different epitopes on the FcR epsilon fragment. A sensitive ELISA for the quantitation of murine IgE was developed with these monoclonal antibodies; the sensitivity was between 2 and 250 ng/ml for detection of serum IgE levels. Good correlation was obtained with protein amounts as determined by enzyme-linked immunosorbent assay (ELISA) and passive cutaneous anaphylaxis (PCA) activities. Both monoclonal antibodies were used to study anaphylactic reactions elicited by IgE antibodies. Both could inhibit PCA reactions and both could elicit reverse PCA reactions.

Animals↗
PubMed1988

[Analbuminemia].

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Animals↗
PubMed1988

Effect of combined administration of a prostacyclin analogue and adriamycin against the artificial metastasis of Meth A cell.

Antimetastatic effect of a stable prostacyclin analogue (PGI2-TEI8153) in combination use with adriamycin (ADM) was investigated. Meth A cell, which had membrane protein of 18,000 daltons specifically bound to platelets, induced platelet aggregation dose-dependently. This platelet aggregation was totally suppressed by PGI2-TEI8153. PGI2-TEI8153 also suppressed the pulmonary arrest as well as pulmonary metastasis of Meth A cells. Combined use of PGI2-TEI8153 and ADM exerted much less antimetastatic effect than that with PGI2-TEI8153 alone, indicating the counteracting effect of ADM against the PGI2-TEI8153. However, this combination use brought about additive antimetastatic effects with 2-fold reduction of pulmonary nodules compared to that of ADM alone. Consequently, even the anticancer drug itself has a negative influence on metastasis, the combined use of PGI2-TEI8153 with it is promising for the prevention of metastasis.

Animals↗
PubMed1988

[Anti-tumor effect of human recombinant TNF].

In this article, the clinical effects of rH-TNF on various cancer patients and the mechanism of self-induction of defense against rH-TNF cytotoxicity in tumor cells and the counter measures against this are reviewed. 1) Clinical effects of rH-TNF Intratumoral administration of rH-TNF was performed in 7 patients and clinical efficacy (PR + MR) was observed in 3/7 (42.9%). Also a reduction of leukemia cells in peripheral blood was observed in all 4 leukemia patients following intravenous (i.v.) administration of rH-TNF. Furthermore, in 2 multiple myeloma patients, the myeloma protein and plasma cells in bone marrow were reduced by i.v. administration of rH-TNF. 2) Self-induction of defense against rH-TNF cytotoxicity Investigation of the effect of TNF on RNA and protein synthesis by tumorigenic and normal cell lines showed that their synthesis in tumor cells was increased at 12 h and peaked at 24 h of incubation with TNF, while that in normal diploid fibroblast (HEL) cells was apparently unaffected by the presence of TNF. Artificial inhibition of either RNA or protein synthesis by L-M cells, upon addition of Act D or CHI increased the cytotoxic effect of TNF, thus suggesting that the elevated RNA and protein synthesis is related not to the cytotoxic reaction itself but rather to a defense mechanism. Similar incubation of HEL cells with TNF in the presence of either inhibitor resulted in the occurrence of cytotoxicity not observed with TNF alone, thus suggesting the existence of a defense mechanism in normal, TNF-resistant cells which is absent or greatly weakened in tumor cells. 3) Combination therapy of rH-TNF with various anticancer drugs. A synergistic increase in the cytotoxic effects of rH-TNF and anti-cancer drugs was demonstrated in vitro The cytotoxicity of rH-TNF against L-M cells in combination with MMC, ADM, Ara-C, ACD, DM, CDDP, VCR and 5-FU was 4 to 347 times as high as that of rH-TNF alone. These results suggest that combination therapy including rH-TNF and anti-cancer drugs may be of value in the treatment of malignancy in human patients.

Antineoplastic Agents↗
PubMed1988

Changes of portal systemic shunting after sclerotherapy and/or partial splenic embolization observed by Tl-201 per-rectal administration.

Tl-201 per-rectal scintigraphy was performed before and after injection sclerotherapy of esophageal varices and/or partial splenic embolization in patients with esophageal varices to observe the changes of portal systemic shunting by these treatments. The changes in the heart-to-liver uptake ratio of Tl-201 after injection sclerotherapy ranged widely from a decrease to an increase with the mean change rate (mean of the absolute value of change rate) +/- 1 SD of 19.0% +/- 19.9%. By partial splenic embolization the heart-to-live uptake ratio was decreased significantly with the mean change rate +/- 1 SD of 26.2% +/- 17.4% (P less than 0.05). This noninvasive and simple method seems to be useful in evaluating pathophysiological changes of portal systemic shunting observed from inferior mesenteric vein blood flow after treatments of portal circulation system.

Administration, Rectal↗
PubMed1987

Regulation of murine IgE production in SJA/9 and nude mice. Potentiation of IgE production by recombinant interleukin 4.

Serum IgE levels were determined in different strains of mice with enzyme-linked immunosorbent assay by using rat monoclonal anti-murine IgE antibodies in normal and in Nippostrongylus brasiliensis-infected mice. After infection, serum IgE levels were high in BALB/c and CB-20, low in SJL/J and SJA/20 mice, and not detected at all in SJA/9 and nude mice. Surface IgE-positive cells were greatly increased in BALB/c and SJL/J mice after infection, but not in SJA/9 and nude mice. Most surface IgE-positive spleen cells were also surface IgM- and surface IgD-positive. When spleen cells from SJA/9 or nude mice were stimulated in vitro with lipopolysaccharide and recombinant interleukin 4 (formerly B cell-stimulating factor 1), IgE was produced and detected in the supernatants of these cultures. In addition, surface IgE-positive cells could be detected in these cultures. Most of the surface IgE-positive cells were surface IgM- and surface IgD-negative, unlike those seen in the spleens of Nippostrongylus-infected BALB/c and SJL/J mice. These observations show that SJA/9 and nude mice have IgE-producing precursor B cells, and after appropriate stimulation interleukin 4 can induce them to secrete IgE.

Animals↗
PubMed1987

Activation and cleavage of the carbon-cobalt bond of adeninylethylcobalamin by diol dehydrase.

Adeninylethylcobalamin (AdeEtCbl) underwent cleavage of the C-Co bond by interaction with apoprotein of diol dehydrase from Klebsiella pneumoniae ATCC 8724, although this analog was quite inactive as coenzyme. Spectroscopic observation indicates that AdeEtCbl was converted to the enzyme-bound hydroxocobalamin without intermediates. The conversion was stoichiometric (1:1) and obeyed the second-order reaction kinetics (k = 0.027 min-1 microM-1 at 37 degrees C) depending upon concentrations of apoprotein and AdeEtCbl. This suggests that the complex formation is the rate-determining step and that AdeEtCbl undergoes rapid C-Co bond cleavage once it binds to the apoenzyme. Substrates and oxygen did apparently not affect the rate of the C-Co bond cleavage. The experiments using [adenine-U-14C]AdeEtCbl and [1(3)-3H]glycerol demonstrated that 9-ethyladenine was the only product formed from the adeninylethyl group of AdeEtCbl during the conversion and that an additional hydrogen atom in the 9-ethyladenine is not derived from the substrate. 1H NMR measurement of the 9-ethyladenine formed enzymatically from AdeEtCbl and DL-1,2-[1,1,2-2H3]propanediol also led to the same conclusion. All of these results indicate that the C-Co bond of AdeEtCbl is activated by diol dehydrase and undergoes heterolysis forming Co(III) and a carbanion or a carbanion-like species, in clear contrast to the homolysis of the C-Co bond of adenosylcobalamin in the normal catalytic process. 9-Ethyladenine formed remained tightly associated with the enzyme. Longer chain homologs, i.e. adeninylpropylcobalamin, adeninylbutylcobalamin, and adeninylpentylcobalamin did not undergo such cleavage of the C-Co bond by diol dehydrase.

Adenine↗
PubMed1987

Detection of IgE antibody-forming cells by passive cutaneous anaphylaxis using cell extract from lymphoid organs.

IgE and IgG2a antibody-forming cells in the lymphoid organs of rats were detected by passive cutaneous anaphylaxis (PCA) reaction using the extract from the tissue. The amount of antigen-specific IgE and IgG2a antibodies in the tissue extract could be expressed as PCA titers in which extract from 10(8) cells/ml was used as starting dilution. The total amount of antigen-specific IgE antibody produced in mouse IgE-producing hybridoma cells was calculated by maximum dilution of the extract to the minimal amount of IgE antibody inducing PCA reaction, i.e., 4 ng/ml. In the case of the extract from mouse IgE antibody-forming hybridomas, the minimal number of hybridoma cells to be detected by this method proved to be 2-3 X 10(4) cells/ml.

Animals↗
PubMed1987

Determination of galactose in human plasma by HPLC with electrochemical detection.

Galactose in plasma from patients with hepatic diseases who had undergone low level galactose infusion was determined by using HPLC with electrochemical detection (LCEC). Agreement between galactose concentration determined by the LCEC and a fluorometric method was remarkably good at moderate levels of galactose in plasma. However, the fluorometric method is not suitable for samples containing very small amounts of galactose (blood from hepatic veins) and even for a few samples at moderate galactose content (blood from peripheral veins), suggesting the presence of an endogenous interference. There was no interference for the quantitation of galactose by the LCEC method, by virtue both of the specificity involved in the electrochemical detection and the separation by liquid chromatography. The detection limit of the LCEC method was 0.4 mg galactose/L blood.

Aged↗
PubMed1987

HPLC electrochemical fluorometric detection of amino acids including tryptophan using 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole.

It has been shown that by electrochemical oxidation 7-nitrobenzo-2-oxa-1,3-diazole-tryptophan (NBD-T) is converted to fluorophores having the same emission and excitation spectra as those for other NBD-amino acids. NBD-dioxindolylalanine was tentatively assumed to be a main electrochemical oxidation product of NBD-tryptophan. A coulochemical cell placed between an analytical column and a fluorometer showed no detrimental effect on the separation of NBD-amino acids by reversed phase HPLC. Highly sensitive fluorescence detection was achieved for amino and imino acids at 10-100 fmol levels. The detection limit for tryptophan was 50 fmol.

4-Chloro-7-nitrobenzofurazan↗
PubMed1987

Tumor cell detection method using complement-mediated cytolytic reaction and imaging sensor system.

A novel tumor-detection system consisting of complement-mediated cytolytic reaction and an image processing system was developed for the simple and rapid determination of tumor cells. The present system consists of a CCD image sensor, image memory board, personal computer, and microscope. When monoclonal antibody 3C4, which is specific to the guinea pig hepatoma L-10, was added to cell suspension, only L-10 cytolysis occurred. Cytolysis caused a decrease in brightness of the cells observed by phase-contrast microscopy. The phase contrast image of the cells before cytolysis was converted to a digitalized signal and stored in computer memory. After cytolysis, a brightness threshold above that of lysed cells was subtracted from the digitalized signal and compared to the signal stored before reaction. L-10 cells in mixed cell suspension were determined specifically by the system. Measurement time was only 2 sec and overall time, including reaction time, was approximately 30 min. Since this method does not require a cell washing process, automation of the whole system is possible.

Animals↗