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Biomedical subjects

K Fujisawa

Publications and source records attributed to K Fujisawa.

At least 289 records · Page 16Linked to original sources
PubMed1984

Hepatic gamma-glutamyl transferase and hepatic fibrosis in patients with alcoholic liver disease.

The activity of gamma-glutamyl transferase (GGT) in the liver of 22 patients with alcoholic liver disease, 24 with nonalcoholic liver disease and 12 normal controls was measured. The enhanced hepatic GGT activity was higher in alcoholic patients and nonalcoholic patients than in the normal controls. No statistical significance of difference could be found in hepatic GGT activity between alcoholic and nonalcoholic patients, while serum GGT activity was markedly elevated in alcoholic patients compared to nonalcoholic patients. There was better correlation between hepatic and serum GGT activity in alcoholic patients. Furthermore the enhanced hepatic GGT activity could contribute to the pathogenesis of liver fibrosis as a result of the investigation for hepatic GGT activity and histological liver fibrosis.

Adult↗
PubMed1984

Effects of 2-nicotinamidoethyl nitrate (nicorandil; SG-75) and its derivative on smooth muscle cells of the canine mesenteric artery.

To clarify the mechanism of vasodilating actions of nicotinamidoethyl nitrate (nicorandil; SG-75) in relation to the chemical structure, we studied the effects of SG-75 and its derivatives [nitrate containing structure; 3,5-bis([2'- nitroxyethyl ] aminocarbonyl )pyridine (SG-114); nicotinamide derivatives: N-(2-hydroxyethyl)nicotinamide (SG-86) and N-(2- nicotinyloxyethyl )-nicotinamide; (SG-103)] on the electrical and mechanical properties of smooth muscle cells of the canine mesenteric artery. SG-75 significantly and SG-114 slightly hyperpolarized the membrane but SG-86 or SG-103 did not. The excitatory junction potential and spike potential evoked by perivascular nerve or direct muscle stimulation were markedly inhibited by SG-75 due to hyperpolarization of the membrane. SG-114 slightly inhibited but SG-86 or SG-103 did not inhibit the excitatory junction potential or spike potential. The K-induced contraction was inhibited by SG-75 (below 39.2 mM) or without hyperpolarization (over 39.2 mM) of the membrane, but SG-114 inhibited the contraction with no hyperpolarization. In concentrations over 39.2 mM K0, SG-114 inhibited the contraction more potently than did SG-75. On the other hand, the norepinephrine-induced contraction was inhibited by SG-75 or SG-114 to the same extent, due to additional hyperpolarization of the membrane, in the case of SG-75. Both agents inhibited but SG-86 or SG-103 did not inhibit the norepinephrine-induced contraction in the Ca-free 2 mM ethylene glycol bis(beta-aminoethyl ether)N,N'-tetraacetic acid containing solution. After the complete depletion of the stored Ca, application of Ca in the presence of SG-75 or SG-114 enabled estimation of the reduction in the amount of Ca stored in the cell, determined by the amplitude of the subsequently produced caffeine-induced contraction in Ca-free ethylene glycol bis(beta-aminoethyl ether)N,N'- tetraacetic acid containing solution. The effects of SG-75 or SG-114 on the norepinephrine-induced contraction in Ca-free solution also indicated a reduction in the Ca stored in the cell. It would appear that SG-75 hyperpolarizes the membrane due to the SG-75 moiety and not to the nitrate residue alone. The relaxation of the tissue induced by SG-75 or SG-114 is due to nitrate action, as observed in the case of nitroglycerin. SG-114 possesses a stronger potency with regard to relaxation of the tissue; however, in vivo, SG-75 may have a more potent vasodilating action than SG-114, as the former inhibits neuromuscular transmission mechanisms.

Animals↗
PubMed1983

Rapid purification and characterization of DNA topoisomerase I from cultured mouse mammary carcinoma FM3A cells.

We have previously shown that a DNA topoisomerase I from mouse mammary carcinoma cells is inhibited by heparin. Taking advantage of this enzyme-heparin interaction, we developed a rapid and efficient method of purification of this enzyme to near homogeneity by extraction of chromatin with 0.15 M phosphate buffer followed by two-step column chromatography on heparin-Sepharose and phenyl-Sepharose. Electrophoresis on sodium dodecyl sulfate-polyacrylamide gels revealed that the final preparation is composed of two polypeptides with apparent Mr approximately 98,000 (p98) and 102,000 (p102), p98 comprising 70% and p102 30%. Extraction and renaturation of the polypeptides from the gel shows that both p98 and p102 seem to possess topoisomerase activity. Partial proteolytic digestion of p98 and p102 with Staphylococcus aureus V8 and chymotrypsin yielded a series of identical peptides, indicating that the two polypeptides are structurally related. The enzyme sedimented through sucrose density gradient with s20,w of 4.0 S, and thus is monomeric in solution.

Animals↗
PubMed1983

Effects of dopamine on neuromuscular transmission in the guinea-pig mesenteric artery.

The effects of dopamine on neuromuscular transmission in the guinea-pig mesenteric artery were investigated using a microelectrode method. Dopamine did not modify the membrane potential or the membrane resistance of the smooth muscle, but did reduce the amplitude of excitatory junction potentials (e.j.p.) and enhance the facilitation of e.j.p. produced by repetitive stimulation. Phentolamine (10(-7) M) enhanced the amplitude and the facilitation of the e.j.p., and with the addition of dopamine (10(-6) M) there was a reduction in the amplitude of e.j.p. but not in the facilitation. Haloperidol and sulpiride (greater than 10(-6) M) increased the amplitude of e.j.p. without altering the postjunctional membrane properties. Haloperidol and sulpiride did not increase the facilitation of e.j.p. produced by repetitive stimulation. In the presence of haloperidol or sulpiride (10(-5) M), dopamine (10(-6) M) did not suppress the amplitude of the e.j.p. These results indicate that in the guinea-pig mesenteric artery, dopamine inhibits the release of transmitter at the presynaptic membrane.

Action Potentials↗
PubMed1983

Capillary GC/MS determination of organic sulfur compounds detected in oyster and mussel caught in the sea as an oil pollution index.

The organic sulfur compounds usually contained in crude oil were used as a marker of oil pollution in shellfish. The oyster (Crassostrea gigas) and mussel (Mytilus edulis) were caught in the Seto Inland Sea of Japan. Capillary-column gas chromatography/mass spectrometry (GC/MS) of extracts showed the presence of organic sulfur compounds of dibenzothiophene and alkyl dibenzothiophenes (C1-C3). The concentration factor of organic sulfur compounds in the oyster and mussel was determined by gas chromatography using a flame photometric detector.

Animals↗
PubMed1983

Effects of a new alpha-adrenoceptor blocking agent, ethyl-7-[4-(2-methoxyphenyl)-1-piperazinyl] heptanoate dihydrochloride (SGB-483), on smooth muscle and neuromuscular transmission in guinea-pig mesenteric artery.

The effects of ethyl-7-[4-(2-methoxyphenyl)-1-piperazinyl] heptanoate dihydrochloride (SGB-483) on the smooth muscle of the guinea-pig mesenteric artery were investigated using microelectrodes. The resting membrane potential was -70.3 +/- 2.1 mV.SGB-483 (10(-8)M - 10(-4)M) did not modify the membrane potential or membrane resistance, as estimated from measurement of current-voltage relationships. Noradrenaline (NA; above 10(-5)M) depolarized the membrane. After pretreatment with SBG-483 10(-5)M or prazosin 10(-6)M, the NA-induced depolarization of the membrane was inhibited; yohimbine (10(-5)M) was ineffective. Phenylephrine and NA (greater than 3 X 10(-7)M) but not clonidine (10(-6)M) contracted the artery. These contractions were inhibited by SGB-483. Following repetitive perivascular nerve stimulation, the amplitude of excitatory junction potentials (e.j.ps) increased to a certain steady state value (e.j.p.(s]. The amplitude of e.j.p.(s) was frequency-dependent. Application of SGB-483 (over 10(-8)M) enhanced the amplitude of e.j.p.(s), dose-dependently with no change in the amplitude of the first e.j.p. (e.j.p.(f] evoked by the first stimulus. After pretreatment with NA, the amplitudes of both e.j.p.(f) and e.j.p.(s) were inhibited, dose-dependently. Following pretreatment with SGB-483 (10(-6) - 10(-5)M), the NA-induced reduction in the amplitude of both e.j.p.(f) and e.j.p.(s) were reversed and the control values restored. Clonidine (10(-7)M) inhibited the amplitude of e.j.p.(f) and e.j.p.(s), and SGB-483 (10(-7)M) partially restored the amplitude of both. Yohimbine (10(-7)M) and phentolamine (10(-7)M) enlarged the amplitude of e.j.p.(s); the amplitude of e.j.p.(f) was inhibited by yohimbine and enlarged by phentolamine. Prazosin (10(-6)M) had no effect on the amplitude of either e.j.p.(f) or e.j.p.(s), at any given stimulus frequency. SBG-483 (10(-7)M) did not enhance the amplitudes of either e.j.p.(f) or e.j.p.(s) following pretreatment with phentolamine (10(-7)M) or yohimbine (10(-7)M) but did enhance the amplitude following pretreatment with prazosin (10(-7)M). SGB-483 possesses the property of an alpha 1- and alpha 2-adrenoceptor antagonist. The alpha-antagonistic action was apparent on post-junctional smooth muscle cells. The alpha 2-antagonistic action on neuromuscular transmission was mediated at pre-junctional nerve terminals to enhance the release of NA. The prejunctional actions of SGB-483 were more selective than those of yohimbine or phentolamine.

Adrenergic alpha-Antagonists↗
PubMed1983

Bu-2470, a new peptide antibiotic complex. I. Production, isolation and properties of Bu-2470 A, B1 and B2.

A strain of Bacillus circulans produced a complex of basic peptide antibiotics designated Bu-2470, which was found to contain four active components, A, B1, B2a and B2b. Bu-2470 A specifically inhibited various Pseudomonas species including P. aeruginosa, P. maltophilia and P. putida, but otherwise its antibacterial spectrum was limited to certain Gram-negative organisms. Bu-2470 B1 and B2 (B2a + B2b) showed broad antibiotic activity against Gram-positive and Gram-negative bacteria including Pseudomonas species. The physicochemical and biological properties of Bu-2470 B1 and B2 are very similar to those of the octapeptin group of antibiotics.

Anti-Bacterial Agents↗
PubMed1983

An epidemic of non-A, non-B hepatitis in Japan.

An epidemic of viral hepatitis was studied in the Okitsu area of Shimizu city in Japan from April 1980 to November 1981. One hundred thirty-six serum samples from patients with viral hepatitis were tested for hepatitis B virus, hepatitis A virus, Epstein-Barr virus, and cytomegalovirus infection. Immunoserological data showed the outbreak of viral hepatitis to be non-A, non-B hepatitis. Epidemiological investigations revealed that the mode of the outbreak was from person to person by close contact and the incubation period was from about 2 to 5 months.

Adolescent↗
PubMed1982

The human Purkinje cells. A Golgi study in pathology.

Purkinje cells from five autopsy cases (a premature newborn infant, a GM1-gangliosidosis, an olivo-ponto-cerebellar atrophy, a multisystem atrophy involving the spinal cord and the brain stem, and a woman of 82 years) were studied using the Golgi impregnation technique. The results were the following: (1) the Purkinje cells showed different abnormalities in each case; (2) the dendrite and cell body showed not only involutive/degenerative but also progressive/plastic changes at the same time in some cases; (3) Purkinje cells which appeared normal in routine histological preparations showed, in some cases, abnormalities of the dendrite and cell body; (4) the abnormality common to the five cases was the loss of branchlet-spines and/or spiny branchlets, probably resulting in loss of the granule cell-Purkinje cell connection. It is discussed that the Golgi technique as applied to morbid human material will be an indispensable tool in the future for the analysis of disease processes on cellular and neurobiological bases.

Adult↗
PubMed1982

The effects of substance P on smooth muscle cells and on neuro-effector transmission in the guinea-pig ileum.

1 The effects of substance P (SP) on the membrane and contractile properties of the smooth muscle cell, or on neuro-effector transmission in the guinea-pig ileum were observed by means of microelectrodes, double sucrose gap and tension recording.2 SP (10(-13)-10(-10)M) induced a phasic contraction of longitudinal muscle strips, but did not change the muscle tone of circular muscle strips, in concentrations up to 10(-8)M.3 SP (10(-10)-10(-8)M) evoked three different membrane responses in longitudinal muscle cells: (i) bursts of spike discharges with no significant change in the membrane potential and input membrane resistance; (ii) bursts of spike discharges with a small but clear depolarization of the membrane and increase in the input membrane resistance; (iii) slow waves with no change in the membrane potential.4 In the circular muscle cells, low concentrations of SP (<10(-8)M) did not affect the membrane potential or the spikes, but SP (10(-7)M) increased the spike discharges with no significant change in the membrane potential.5 SP (10(-10)M) reduced the threshold depolarization required for the generation of action potentials with no change in membrane potential of the longitudinal muscle cells.6 Pretreatment with atropine (5 x 10(-6)M), tetrodotoxin (TTX 10(-6)M) or baclofen (4.7 x 10(-6)M) had no effect on the excitatory actions of SP on the smooth muscle cells of longitudinal and circular muscle strips.7 Excitatory actions of SP on the membrane potential or spike activities of longitudinal muscle cells were preserved in NaCl but not in Ca-deficient solution.8 SP (10(-10)-10(-9)M) enhanced the amplitude of the excitatory junction potentials (e.j.ps) evoked by electrical field stimulation in longitudinal muscle cells with no change in the membrane potential and input resistance. SP (10(-10)-10(-9)M), however, did not change the amplitude of inhibitory junction potentials (i.j.ps) recorded from the circular muscle cells.9 These results indicate that SP in relatively low concentrations acts on both smooth muscle cells and on excitatory neuro-effector transmission in the longitudinal muscle; the main site of the action of SP is probably the muscle membrane.

Animals↗