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Biomedical subjects

M Yamazaki

Publications and source records attributed to M Yamazaki.

At least 559 records · Page 31Linked to original sources
PubMed1992

Effects of sodium L-lactate and sodium racemic lactate on intraoperative acid-base status.

Lactated Ringer's solution is frequently used to avoid metabolic acidosis during fluid resuscitation. The standard lactated Ringer's solution contains racemic lactate, an equal mixture of the D- and L-stereoisomers. We investigated whether sodium L-lactate or sodium racemic lactate (DL-lactate) is more effective for increasing buffering capacity in body fluids. For the purpose of this comparison, Ringer's solutions containing no lactate, sodium L-lactate, or racemic lactate at a concentration of 84 mEq/L (three times more than the ordinary level) were infused in patients under general anesthesia during tympanoplasty. Although differences occurred among the three groups in blood concentrations of L-lactate, D-lactate, and the L-lactate/pyruvate ratio, no differences occurred between the two lactate groups in either bicarbonate ion concentration or base excess. The amount of buffering capacity increased significantly in both lactate groups, compared with preinfusion levels, and was more than the values in the nonlactated Ringer's solution group. We conclude that sodium racemic lactate is metabolized at nearly the same rate as that of sodium L-lactate.

Acid-Base Equilibrium↗
PubMed1992

Morphological and immuno-cytochemical characterization of a hetero-spheroid composed of fibroblasts and hepatocytes.

A novel method for the preparation of spheroids containing two types of cells (hetero-spheroid) has been successfully developed by utilizing a collagen-conjugated thermo-responsive polymer, poly-N-isopropyl acrylamide (PNIPAAm), as a cell substratum. PNIPAAm solidifies above its lower critical solution temperature (LCST, about 30 degrees C), and instantly dissolves into the culture medium below its LCST. We firstly seeded and cultured human dermal fibroblasts on the substratum up to a confluent state and then seeded rat primary hepatocytes onto the fibroblast monolayer. The heterospheroid was prepared by detaching the hepatocyte-attached fibroblast monolayer at a temperature below LCST and culturing it on the non-adhesive substratum. The surface area of the substratum and the seeding population ratio of each cell precisely and reproducibly regulated the size and the cell composition of the resulting hetero-spheroid, respectively. Histological and immuno-cytochemical observations of spheroids revealed characteristic organizations of fibroblasts and hepatocytes within a spheroid because the latter cells expressed albumin for up to at least 3 weeks. TEM study of the hetero-spheroid showed the presence of structures morphologically similar to the Disse's space and the bile canaliculus, which are features characteristic of liver. These findings suggest that the method described above is useful for making a hetero-spheroid that morphologically and functionally resembles tissues or organs in vivo, i.e. an organoid.

Animals↗
PubMed1992

Biopolymers from marine invertebrates. XIII. Characterization of an antibacterial protein, dolabellanin A, from the albumen gland of the sea hare, Dolabella auricularia.

An antibacterial factor, dolabellanin A, was purified from the albumen gland of a sea hare, Dolabella auricularia. Purified dolabellanin A was a glycoprotein of 250 kilodaltons consisting of 4 subunits, and showed both antibacterial and antineoplastic activities. The two activities were lost in parallel on heating and at low and high pH. This factor was half-maximally active for gram-positive and -negative bacteria at 0.018-0.48 microgram/ml, and its action was not bactericidal but bacteriostatic. Dolabellanin A did not induce morphological elongation of bacteria or the release of adenosine triphosphate, but it completely inhibited the syntheses of deoxyribonucleic acid (DNA) and ribonucleic acid by E. coli within 6 min. These results suggest that dolabellanin A, which is found in a marine invertebrate, the sea hare, is a new antibacterial protein, and that it exerts its action by inhibiting nucleic acid synthesis, as does a DNA-inhibiting chemotherapeutic drug.

Amino Acid Sequence↗
PubMed1992

Biopolymers from marine invertebrates. XII. A novel cytolytic factor from a hermit crab, Clibanarius longitarsus.

Bioactive polymers were sought in marine arthropoda and a novel cytolytic factor was found in a hermit crab, Clibanarius longitarsus. The partially purified factor showed activity in fractions corresponding to a molecular weight of about 10 kilodaltons on a Sephadex G-75 column. This cytolytic factor was halfmaximally active for tumor cells at 0.13-0.66 micrograms/ml and for normal cells at 1.9-82 micrograms/ml. Tumor lysis by the factor was time dependent and was complete within 12 h. This bioactive polymer was labile on heating, at low and high pH.

Animals↗
PubMed1992

Analgesic components from bornean medicinal plants, Tabernaemontana pauciflora Blume and Tabernaemontana pandacaqui Poir.

The analgesic components were isolated from a Bornean medicinal plant, Tabernaemontana pauciflora Blume (syn. Ervatamia blumeana Mark gr.), and the major components were identified as coronaridine and 3-(2-oxopropyl)coronaridine. Four minor components were estimated to be 5R- and 5S-(2-oxopropyl)coronaridine, 3-(2-oxopropyl)voacangine and 3,3'-(oxopropyl)dicoronaridine, which might be produced during the isolation process. Voacangine was also isolated as a major component of T. pandacaqui Poir. Coronaridine and voacangine exhibited significant analgesic and hypothermic effects in mice at a dose of 25 mg/kg, p.o., while 3-(2-oxopropyl)coronaridine was less effective. The former two compounds also revealed a surface anesthesia.

Analgesics↗
PubMed1992

Radioimmunoassay for the determination of 2-methoxyestriol concentration in plasma of pregnant women.

A specific assay method has been developed for the determination of 2-methoxyestriol in plasma of pregnant women. The quantitation was achieved by radioimmunoassay after extraction of the plasma with ethyl acetate and purification on a Sephadex LH-20 column. In order to obtain the immunogen for 2-methoxyestriol, 6-oxo-2-methoxyestriol was converted to its 6-(O-carboxymethyl)oxime derivative. The derivative was then coupled to bovine serum albumin by the mixed anhydride method, and rabbits were immunized with this conjugate. The antiserum obtained was partially purified by affinity chromatography on estrone 17-(O-carboxymethyl)oxime-aminohexyl Sepharose conjugate to eliminate the cross-reactive antibodies. Plasma 2-methoxyestriol concentrations in pregnancy were estimated to be mean values of 41.1 pg/ml (12th-14th week), 85.3 pg/ml (27th-29th week), and 97.5 pg/ml (37th-41st week).

Cross Reactions↗
PubMed1992

Isolation, identification and pharmacological studies on three toxic metabolites from a mushroom, Hebeloma spoliatum.

Three metabolites, tentatively named HS-A, -B and -C, were isolated from a mushroom, Hebeloma spoliatum, as the fatal toxic principles to mice. HS-A was identified as 3-acetyl-2-(3'-hydroxy-3'-methyl)glutarylcrustulinol, which has been isolated from Hebeloma crustuliniforme and H. sinapizans as a cytotoxic principle. HS-B and -C were deduced to be 3,21-diacetyl-2-(3'-hydroxy-3'-methyl)glutarylcrustulinol and 3-acetyl-2-(3'-hydroxy-3'-methyl)glutarylanhydrocrustulinol, respectively, from their chemical and spectral data. Intraperitoneal administration of HS-A, -B and -C at a dose of 100 mg/kg caused death after paralysis of the limbs in mice. The compounds caused relaxation of mouse small intestine contracted by acetylcholine chloride or barium chloride treatment in vitro. They appear to exhibit a papaverine-like relaxation effect.

Animals↗
PubMed1992

[Activity of Enterococcus faecalis (FK-23) preparation as a biological response modifier].

The biological activity of a preparation of heat killed cells of Enterococcus faecalis, FK-23 which was isolated from the feces of a healthy human, was investigated in C3H/He mice. Intraperitoneal injection of the preparation caused an accumulation of neutrophils and macrophages in the peritoneal cavity of the mice 6 h later. As a parameter of the activation of macrophages, the effect of the FK-23 preparation on the production of tumor necrosis factor (TNF) was examined. The mice were given two consecutive intravenous injections of the preparation at a dose of 10 micrograms/mouse and, 3 h later, of 300 micrograms/mouse. The TNF level in the sera reached 99 U/ml in mice 2 h after the second injection. This preparation also stimulated peritoneal macrophages to produce TNF in vitro and increased the capacity of neutrophils to adhere to plastic plates and to release active oxygens, but did not induce blastogenic transformation of lymphocytes. These results suggest that the FK-23 preparation is a biological response modifier (BRM) with various activities on phagocytes similar to a streptococcal antitumor agent, OK432.

Animals↗
PubMed1992

[Mechanisms of histamine-induced relaxation in isolated dog mesenteric arteries and veins].

Mechanisms of histamine-induced relaxation in dog mesenteric artery and vein strips were compared. Histamine elicited a concentration-related relaxation in the arterial strips contracted with prostaglandin (PG) F2 alpha; the relaxations induced at 5 x 10(-7) M or higher were composed of phasic and tonic patterns. The phasic component of relaxation was inhibited by chlorpheniramine, but not by cimetidine. Combined treatment with the H1 and H2 antagonists abolished the amine-induced relaxation. The tonic component was inhibited by cimetidine. The phasic relaxation was attenuated by removal of the endothelium. Treatment with indomethacin inhibited the phasic component in the strips with endothelium, but did not influence the relaxation after endothelium denudation. Combined treatment with indomethacin and cimetidine, but not chlorpheniramine, abolished the response. On the other hand, histamine produced a concentration-related, tonic relaxation in the mesenteric vein strips. The relaxation was not influenced by indomethacin, endothelium-denudation, and chlorpheniramine, but was abolished by cimetidine. It may be concluded that the phasic relaxation of dog mesenteric arterial strips is mediated mainly by H1 receptors in the endothelium, resulting in the synthesis and release of PGI2. The tonic relaxation appears to be elicited by activation of H2 receptors in smooth muscle. Mesenteric vein relaxations induced by histamine are likely to be mediated solely by H2 receptors in smooth muscle.

Animals↗
PubMed1992

Paraneoplastic cerebellar degeneration: successful early detection and treatment of cancer through characterization of the anti-Purkinje cell antibody.

Paraneoplastic cerebellar degeneration (PCD) is thought to be caused by an autoantibody against both tumor and neuronal tissue. Such autoantibodies are most frequently detected in patients with gynecological or breast cancer, and are designated as anti-Yo. We report here a patient with PCD whose underlying cancer could not be detected despite extensive tumor survey. IgG in her serum and cerebrospinal fluid reacted with the cytoplasm of cerebellar Purkinje cells immunohistochemically. On immunoelectron microscopy, the endoplasmic reticulum and Golgi complex were stained. Her IgG bound to the 58 kD band on immunoblots of cerebellar proteins. A reaction was also observed with the recombinant proteins deduced from the complementary DNA clone encoding a neuronal cell antigen reported by Sakai et al (Ann Neurol 28: 692, 1990). Based on these results, successful early resection of fallopian tube adenocarcinoma was performed. It is crucially important to characterize these PCD related autoantibodies for the early treatment of underlying malignant tumors.

Adenocarcinoma↗
PubMed1992

44-Homooligomycins A and B, new antitumor antibiotics from Streptomyces bottropensis. Producing organism, fermentation, isolation, structure elucidation and biological properties.

Oligomycin antibiotics, 44-homooligomycin A (NK86-0279 II) and B (NK86-0279 I) are newly discovered antitumor antibiotics with the substitution of ethyl for methyl at carbon 26. They were isolated from the culture broth of Streptomyces bottropensis NK86-0279. The structure of these two compounds was deduced by spectroscopic and X-ray crystallographic analyses. These antibiotics showed potent antitumor activities against various tumor cells in vitro, and were active against Colon 26 carcinoma in vivo. Although they showed no activity at 1,000 micrograms/ml against Gram-positive and Gram-negative bacteria and yeast, they have antifungal activity.

Antibiotics, Antineoplastic↗
PubMed1992

Biosynthesis of griseolic acids: incorporation of 13C-labeled compounds into griseolic acid A.

Biosynthesis of griseolic acids, competitive inhibitors of cyclic nucleotide phosphodiesterase, was investigated with the culture of a producing strain of Streptomyces griseoaurantiacus. 13C-Labeled and 15N-labeled compounds were added into the culture, and 13C-enriched and 15N-enriched griseolic acid A was isolated from the culture medium and analyzed by 13C NMR and 15N NMR spectroscopy. The compounds added to growth medium were [2-13C]acetate, [1,2-13C]acetate, [1,4-13C]succinate, [1-13C]glucose, [6-13C]glucose, [2-13C]ribose, and [1-13C, 15N]glycine. The results suggest that adenosine, which is formed from amino acids and sugars contributes the adenine and ribose moieties to griseolic acid A. The data also suggest that a dicarboxylic acid from the Krebs tricarboxylic acid cycle contributes to the dicarboxylic part of the compound.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1992

[A case of Machado-Joseph disease--cerebral blood flow and cerebral metabolic rate of oxygen].

A 51-year-old woman, with progressive gait disturbance and dysarthria, had been diagnosed as Menzel-type spinocerebellar degeneration. Later, she developed dystonic posture of upper limbs and bulging eyes. She was diagnosed as Machado-Joseph disease from neurological findings, which consisted of cerebellar signs, pyramidal tract signs and extrapyramidal tract signs and peripheral neuropathy. She died suddenly of unknown origin. Her illness lasted about 13 years. Neuropathological findings showed moderate neuronal loss with gliosis in the subthalamic nucleus, globus pallidus, substantia nigra, dentate nucleus, oculomotor and hypoglossal nucleus and anterior horn. Positron emission tomography (PET) using 15O steady state inhalation technique revealed reduction of cerebral blood flow and cerebral metabolic rate of oxygen in not only cerebellum but also cerebral cortex. These findings are different from typical PET findings of spinocerebellar degeneration.

Brain↗
PubMed1992

[A case of acid maltase deficiency (juvenile type)--immunohistochemical and biochemical study].

A 22-year-old housewife was referred to us for review of progressive proximal muscle weakness which started at 15 years of age. A biopsy of left rectus femoris muscle showed acid phosphatase positive vacuoles partly filled with PAS-positive material. Acid maltase activity of the cultured fibroblasts was pathologically low at 0.4 nmol/mg protein considering 161.0 +/- 32.4 nmol/mg protein as a normal range. A diagnosis was made of acid maltase deficiency (juvenile type). Western blot using anti-acid maltase polyclonal antibody revealed 115 and 70 kDa bands in control muscles, where as only the 115 kDa band, a presumable precursor of the enzyme, was visualized in the patient. By immunohistochemistry using the same antibody the epitope was localized to the acid phosphatase positive vacuoles and immunoelectron microscopy demonstrated the acid maltase immunoreactivity within lysosomes. We concluded that the protein precursor unable to proceed into mature enzyme can access to lysosomes from endoplasmic reticulum through Golgi complex in the present case.

Adult↗