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Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 1,009 records · Page 56Linked to original sources
PubMed1981

Purification, enzymatic properties, and active site environment of a novel manganese(III)-containing acid phosphatase.

A new manganese-containing acid phosphatase has been isolated and crystallized from sweet potato tubers. The pure enzyme contains one atom of manganese per Mr = 110,000 polypeptide and shows phosphatase activity toward various phosphate substrates. The pH optimum of the enzyme was 5.8 and the enzyme activity was inhibited by Cu2+, Zn2+, Hg2+, AsO43-, and MoO42-. This stable metalloenzyme is red-violet in color with an intense absorption band at 515 nm (epsilon - 2460). Our electronic, circular dichroism, and electron spin resonance findings strongly indicate that the Mn-valence state of the native enzyme is trivalent. When the Mn-enzyme is excited by the 5145 A line of Ar+ laser, prominent Raman lines at 1230, 1298, 1508, and 1620 cm-1 were detected. This Raman spectrum can probably be interpreted in terms of internal vibration of a coordinated tyrosine phenolate anion. The tryptophan-modified enzyme showed a positive Raman band at 370 cm-1, which is preferentially assigned to a Mn(III)-S streching mode. The modification of the Mn-enzyme by N-bromosuccinimide led to a large decrease in the fluorescence intensity of 335 nm which was dominated by its tryptophan residues within a considerable hydrophobic environment. The acid phosphatase activity was significantly decreased by the tryptophan modification. With respect to the active site donor sets, the Mn(III)-containing acid phosphatase is distinctly different from the Zn(II)-containing alkaline phosphatase. Of interest is also the appreciable similarity of some enzymatic and spectroscopic properties between the present enzyme and uteroferrin.

Acid Phosphatase↗
PubMed1981

Effect of Bacillus Calmette-Guérin cell wall skeleton on the induction of the cytotoxic and suppressor T cells against syngeneic tumor in the mouse.

The effect of Bacillus Calmette-Guérin cell wall skeleton (BCG-CWS), which is one of the well-established immunopotentiators, on the induction of either cytotoxic or suppressor T cells against syngeneic tumor S1509a was investigated by an in vitro assay system. BCG-CWS showed an apparent augmenting activity in the induction of cytotoxic T cells against a syngeneic tumor when it was administered subcutaneously into mice with mitomycin C (MMC)-treated tumor cells in a form of oil-in-water emulsion. In addition, cytotoxic T cell activity was dominantly generated in regional lymph nodes. Furthermore, the immunized animals developed stronger resistance against the second inoculum of the same viable tumor cells. However, BCG-CWS had no effect on the induction of suppressor T cells in tumor-bearing host (TBH), and could not induce cytotoxic T cells against the homologous tumor in TBH in which suppressor T cells had been rapidly activated. The growth of tumor was neither suppressor nor enhanced, even if an oil-attached BCG-CWS was administered in TBH.

Animals↗
PubMed1981

Aarskog syndrome with isolated growth hormone deficiency.

A 5-year-old male with the Aarskog syndrome is described. He had abnormal facies, short stature, short fingers with interdigital webbing, a saddle type scrotum and mild mental retardation. In addition, he had isolated growth hormone deficiency as evidenced by the insulin, arginine, and propranolol-glucagon tests. An arginine test after short-term stimulation with estrogen further supported this diagnosis. His mother had minor abnormalities of the hands and feet, and slight mental retardation.

Child, Preschool↗
PubMed1981

Further investigations of immunoreactive carcinoembryonic antigen (CEA) in colorectal cancer patients--with particular emphasis on the correlation between immunoreactive CEA levels in tissue, feces and blood.

Immunoreactive carcinoembryonic antigen (IR-CEA) levels in colorectal cancer and mucosal tissues, feces and blood were measured in 14 colorectal cancer patients to study the correlation. IR-CEA levels in colorectal cancer tissues were about 30 times higher than those in colonic mucosal tissues. The correlation coefficient between IR-CEA levels in the tumor tissue and serum was 0.654 (p less than 0.02). We assumed that the total tumor IR-CEA levels were the product of the tumor IR-CEA level, by the estimated tumor weight. The correlation coefficient between the serum IR-CEA level and total tumor IR-CEA level was 0.750 (p less than 0.001). When the patients were divided into two groups with more and less a total tumor IR-CEA level of 65,000 ng, respectively, the statistical difference in serum IR-CEA levels was p less than 0.001. The differences in fecal IR-CEA levels between these two groups, however, are statistically insignificant (p less than 0.3). We assumed that there was a positive correlation between the IR-CEA levels in blood and tumor from the consideration that circulating IR-CEA originates from the metabolic imbalance of its production in colorectal cancer tissues over its degradation in the liver. Moreover, it is essential to consider that the fecal IR-CEA levels may be influenced by the following three factors: the intraluminal direct release of CEA from tumor, no degradation process of CEA in the gut lumen, and the intraluminal transport rate of colonic contents.

Aged↗
PubMed1981

Comparative efficacy of antitumor treatment for liver metastases from colorectal cancer.

A retrospective study of 37 colorectal cancer patients with synchronous liver metastases was made. Of these patents, 6 who had undergone primary tumor removal were treated with considerable success by hepatic arterial infusion of 5-FU and mitomycin C. Ten patients who underwent primary tumor excision were treated by oral chemotherapy using fluorinated pyrimidines. These patients survived about 23 months. On the other hand, 12 patients after primary tumor removal without cancer chemotherapy survived for about 10 months. Six patients without antitumor treatment for both primary tumor and hepatic metastasis survived about 5.2 months. The overall results of this study suggest that intrahepatic arterial infusion is of practical importance for hepatic metastases from colorectal cancer and that oral chemotherapy is indeed effective for selected patients.

Adult↗
PubMed1981

Serial monitoring of serum estradiol and progesterone levels during the HMG-HCG therapy in sex anovulatory women.

Serum estradiol (E2) and progesterone (P) levels were radioimmunoassayed every or every other day for monitoring the HMG-HCG therapy in six anovulatory patients, and the clinical significance of measuring steroid hormones as precautionary counterplot against the ovarian hyperstimulation syndrome and multiple pregnancies was evaluated. Administration of HCG is recommended to trigger ovulation when serum E2 levels reach 400-600 pg/ml. Mean peak P level in 7-8 days after ovulation induced by HMG-HCG was 22.9 ng/ml, which is significantly higher than P levels of the same period in spontaneous and clomiphene-induced ovulations. This result suggests that there may occur multiple ovulations which result in multiple pregnancies in HMG-HCG therapy.

Anovulation↗
PubMed1981

Inhibition from locus coeruleus of caudate neurons activated by nigral stimulation.

Electrophysiological studies were performed to determine if the locus coeruleus (LC) plays a role in regulating activity of caudate nucleus (CN) neurons. Cats were anesthetized with alpha-chloralose and when conditioning stimuli were applied to the LC, preceding the test stimulus, there was a significant inhibition of spike generation in 33 out of 93 CN neurons transsynaptically activated by test stimulus to the pars compacta of the substantia nigra (SN). An inhibition of spike generation with LC conditioning stimulation and iontophoretic application of noradrenaline was obtained in 9 out of the same 23 CN neurons and 8 neurons remained unaffected with either treatment. In contrast to these neurons, LC conditioning stimulation did not affect the spontaneous firing and spike generation of CN neurons antidromically excited by SN stimulation. Spike firing of CN neurons transsynaptically activated by motor cortex stimulation remained unaffected with LC conditioning stimulation. These results suggest that noradrenaline derived from the LC produced an inhibition of spike generation in about one-third of CN neurons tested and transsynaptically activated by SN stimulation.

Animals↗
PubMed1981

Studies on aspirin derivatives with very little side effect. II. Potent platelet anti-aggregant activity and no mutagenicity of aspirin-isopropylantipyrine (AIA).

The effect of a new aspirin derivative, aspirin-isopropylantipyrine (AIA), with very little gastric ulcerogenic activity and very slight acute toxicity and with analgesic, antipyretic anti-inflammatory, and platelet aggregation inhibitory activities was evaluated in vitro and ex vivo and compared with those of aspirin and isopropylantipyrine (IA). In vitro, AIA, aspirin and IA (50-200 microM) caused concentration-dependent inhibition of collagen-induced aggregation in rabbit platelets although AIA was several-fold more active than the others Arachidonic acid-induced aggregation was inhibited by all three agents (200 microM) in the following magnitude; IA greater than aspirin greater than AIA. Three agents did not influence primary ADP-induced aggregation. The in vitro effects on the release-inducing aggregants were confirmed by ex vivo experiments in rats. These demonstrated that AIA and aspirin (50 mg/kg) exhibited almost identical inhibitory potencies in the extent and the rate of collagen-induced aggregation 4 h after subcutaneous injection. AIA was still effective 24 h after administration as well as aspirin. IA was less effective, differing from the results in vitro. AIA had no effect on plasmin activity and blood flow through the common carotid artery. AIA (1 mM) maintained spreading and beating of myocardial cells in a serum-free culture. As special toxicity trials on AIA mutagenecity tests were made by the Rec-assay with Bacillus subtilis, by the plate culture with Escherichia coli, and by the Ames system with Salmonella typhimurium. AIA was found to have no mutagenic effect under any of those methods and to have no effect on the mutagenic action of 3, 4-benzopyrene under the liver microsome test using the Ames system.

Animals↗
PubMed1981

Dopaminergic inhibition from substantia nigra of caudate neurons activated by cortical stimulation.

Studies were performed to elucidate the role of dopamine originating in the pars compacta of the substantia nigra (SN) on caudate nucleus (CN) neurons receiving input from the motor cortex using cats anesthetized with alpha-chloralose. Activation with cortical stimulation was observed in 50 CN neurons, five out of which also excited by SN stimulation. Conditioning stimuli applied to the SN, 30 msec preceding the test stimulus to the cortex, produced a significant inhibition of spike generation upon cortical stimulation in 28 out of 45 neurons tested and did not affect the remaining 17 neurons. The mean spike number of the 45 neurons was significantly reduced with SN conditioning stimulation. When dopamine up to 200 nA was iontophoretically applied to CN neurons, there was a significant inhibition of the spike generation with cortical stimulation in 9 out of 16 neurons. The mean spike number of the 16 neurons upon cortical stimulation was significantly reduced during dopamine application. In addition, a close correlation was observed between the effects of SN conditioning stimulation and iontophoretic dopamine. These results suggest that dopamine derived from the SN produces an inhibition of CN neurons receiving input from the motor cortex.

Animals↗
PubMed1981

Scanning and transmission electron microscope studies on the organ of Corti and stria vascularis in human fetal cochlear ducts.

The organ of Corti in human fetuses aged 5 and 7 months, respectively, was observed with the scanning and transmission electron microscope (SEM and TEM). By SEM observation, bulbous cytoplasmic structures protruding from the apical surface of the outer and inner hair cells were observed as was the case in SEM reports by others. By TEM observation, it was revealed that these structures are cytoplasmic projections from the so-called cuticular notch which, in adults, houses the basal body and is a site for synthesis of auditory stereocilia and a single kinocilium. The stria vascularis was examined only in the 5 month specimen. The cytoplasm of the differentiating marginal cells is characterized by the presence of thick walled tubular membranes. The observation suggests that this tubular system may represent "a particular site" for secretion of some ions into the endolymph in the fetal condition.

Cochlea↗