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Biomedical subjects

E Sato

Publications and source records attributed to E Sato.

At least 379 records · Page 21Linked to original sources
PubMed1988

[Cultivation of mouse oocytes in vitro: the ability to resume meiosis].

It is well established that fully grown oocytes from sexually mature mice are capable of resuming meiosis when cultured in vitro. However it has not been established at what stage during the growth the oocyte acquires the ability to mature. The present study was undertaken to determine the precise stage of growth at which the ability to resume meiosis is acquired in ICR strain mice. Oocytes of various sizes were isolated from the ovary by mechanical dissection. This method yielded about 30% growing and fully-grown oocytes from the ovary. Cumulus-free oocytes dissociated from the ovaries of 5-week-old mice were cultured in vitro in a chemically defined medium for 3 hr. None of the 61- to 65-microns-diameter oocytes resumed meiosis; however 81.8% of the 66- to 70-microns-diameter oocytes were able to resume meiosis. Fifty- to 60-microns-diameter oocytes recovered by enzymatic dispersal of the basement membrane of isolated growing follicles were unable to resume meiosis. Follicle-enclosed 50- to 60-microns-diameter oocytes did not resume meiosis even when cultured in a medium containing Ca-ionophore A 23187 or 8-bromoadenosine 3', 5'-cyclic monophosphate which are known to induce resumption of meiosis of oocytes in Graafian follicles. These results indicate that the ability to resume meiosis is acquired dramatically at a specific stage of oocyte growth.

Animals↗
PubMed1988

Chemicals influencing maturation, activation, and degeneration of bovine oocytes in culture.

The effects of the dibutyryl cyclic adenosine 3',5'-monophosphate, calmodulin antagonist W7, and ovarian glycosaminoglycans on polar body extrusion, "nucleus" formation, and segmentation of bovine oocytes were examined in vitro. Dibutyryl cyclic adenosine 3',5'-monophosphate (100 microM) accelerated the extrusion of first polar body; however, W7 (20 microM) suppressed the formation of the first polar body. Spontaneous "nucleus" formation resembling pronucleus formation in oocytes was accelerated in the presence of dibutyryl cyclic adenosine 3',5'-monophosphate at concentrations of greater than 20 microM. The spontaneous segmentation, which is a degenerative change, was suppressed in the presence of bovine follicular fluid-glycosaminoglycans at concentrations of 250 micrograms/ml or greater. These results may indicate that maturation, activation, and degeneration of bovine oocytes in culture are modulated by dibutyryl cyclic adenosine 3',5'-monophosphate, W7, and ovarian glycosaminoglycans.

Animals↗
PubMed1987

Inhibition of metabolic response of polymorphonuclear leukocyte by biscoclaurine alkaloids.

Effects of biscoclaurine alkaloids on the various stimulus-responses of PMN, especially on the O2-. generation of PMN, were investigated. Results obtained were: cepharanthine inhibited various metabolic responses of PMN, its biological action probably being due to its membrane modifying action. Inhibition of O2-. generation by cepharanthine was stronger than any other inhibition of metabolic responses of PMN. The inhibitory effect of various biscoclaurine alkaloids on the O2-. generation of PMN was the descending order of tri-, di- and mono-ether type; the coclaurine type showed only a weak effect.

Alkaloids↗
PubMed1987

Thrombomodulin as a marker for vascular tumors. Comparative study with factor VIII and Ulex europaeus I lectin.

Thrombomodulin (TM) is a newly described endothelial cell-associated protein that functions as a potent natural anticoagulant by converting thrombin from a procoagulant protease to an anticoagulant. Various vascular tumors were characterized with immunoperoxidase staining with the use of a polyclonal anti-TM serum. The staining patterns of TM were compared with those of Factor VIII-related antigen (FVIII-RAG) and Ulex europaeus agglutinin-I (UEA-I), which have been used as markers for endothelial cells. The results showed that TM is a specific and a highly sensitive marker for angiosarcomas in comparison with FVIII-RAG or UEA-I. In contrast, UEA-I is more sensitive for benign vascular tumors than TM or FVIII-RAG. The other mesenchymal tumors of nonvascular origin showed negative staining for three endothelial markers. These results indicate that TM is a new specific and sensitive tool for the diagnosis of angiosarcomas.

Antigens↗
PubMed1987

A Lewis X hapten is the major glycolipid of Japanese quail intestine.

A fucolipid isolated from Japanese quail intestine was identified as beta-galactosyl-1,4-(alpha-fucosyl-1,3-) beta-N-acetylglucosaminyl-1,3-beta-galactosyl-1,4-beta-glucosyl-1,1-cera mide, a glycolipid which exhibits X-hapten activity. Analysis of the tissue at various embryonic stages showed that the fucolipid is characteristically present at later stages of organogenesis.

Aging↗
PubMed1987

Prevention of spontaneous degeneration of mouse oocytes in culture by ovarian glycosaminoglycans.

Mouse follicular oocytes cultured for more than 72 h in modified Krebs-Ringer solution in vitro undergo spontaneous segmentation to form "blastomeres" with or without nuclear fragments or chromatin. Glycosaminoglycans (GAGS) isolated from bovine follicular fluid (bFF) and added to the suspending medium at concentrations of 0.25 mg/ml or greater prevented the occurrence of spontaneous segmentation in isolated cumulus-free mouse oocytes in a dose-dependent manner. The active material was isolated from bFF by chromatography on Dowex 1-X2. The fraction eluted with 0.5 M NaCl possessed the greatest biological activity. Preparations of purified bFF-GAGs and hyaluronic acid and chondroitin sulfate from a commercial source prevented the occurrence of segmentation. Hyaluronic acid was more potent than chondroitin sulfate. The present results show that GAGs prevent segmentation of oocytes in vitro.

Animals↗
PubMed1987

Correlation between glycoconjugate expression and fucosyltransferase activity in human colorectal carcinoma.

Using the surgically extirpated specimens from 9 patients with colorectal carcinoma, fucosyltransferase activities in the carcinoma tissue and the normal mucosa were measured and were compared with the histochemical findings of glycoconjugates which were shown by staining with lectins reacting with blood group antigens and related substances. The fucosyltransferase activities of the carcinoma tissue were well correlated with the overall findings of lectin stainings after neuraminidase treatment. The more intense the carcinoma tissue was stained, the higher the fucosyltransferase activity was shown. However, there were marked differences in the fucosyltransferase activities by the portions measured, depending upon the relative amount of carcinoma tissue and interstitial tissue; in the invasive portion with less carcinoma tissue, the activity was generally low in comparison with that in the surface area where carcinoma tissue was rather abundant. Thus, the morphological and lectin histochemical finding are of paramount importance for the evaluation of glycosyltransferase activity in human colorectal carcinoma.

Adult↗
PubMed1987

A comparative microphotometric analysis of adult T-cell leukemia/lymphoma (ATLL) in the skin and mycosis fungoides (MF).

In the skin lesions of 16 adult T-cell leukemia/lymphoma (ATLL) and 13 mycosis fungoides (MF), morphological features of cutaneous infiltrates and their cell kinetics were evaluated through microphotometry of nuclear DNA content and nuclear size on Feulgen-stained sections. Lymphomas comprising some giant cells with irregular-shaped nuclei were found only in ATLL and these cells revealed aneuploid high DNA values. In contrast, neoplastic cells with pale cytoplasm in the Giemsa stain were seen more frequently in MF (69.5%) than in ATLL (12.5%). Patterns of the cutaneous infiltration according to skin microenvironments such as perivascular areas, dermal papillae, and periadnexal areas, were similar in the both entities. In the perivascular areas a mixed proliferation of lymphoma cells and non-neoplastic lymphocytes was conspicuous. The lymphoma cells were determined by high DNA values and large nuclear sizes. But the ratio of lymphoma cells to non-neoplastic cells in the infiltrates in the perivascular areas was higher in ATLL than in MF. In the dermal papillae and around the skin appendages, lymphoma cells predominated. Lymphoma cells which formed a plaque or tumor in the dermis contained many actively proliferating cells having higher DNA values and larger nuclear sizes than the lymphoma cells without tumor formation. One case of ATLL intermediate cell type showed, however, few proliferating cells inspite of tumor formation, suggesting a pooling or a long life-span in the skin.

Cell Cycle↗
PubMed1987

Comparative microcytometric analysis of European peripheral T-cell malignant lymphomas (EPTL) and adult T-cell leukemia/lymphomas (ATLL) in Japan.

A simultaneous microcytometric analysis of nuclear DNA content and size was performed in 8 European peripheral T cell lymphomas (EPTL) and 8 adult T-cell leukemia/lymphomas (ATLL), comparing their patterns on the nuclear density scattergram (NDS) of DNA content versus nuclear size. The intermingling lymphocytes with or without irregular-shaped nuclei in EPTL and ATLL were interpreted as stimulated reactive. Medium-sized cell-dominated T-zone lymphomas and ATLL pleomorphic medium-sized cell type showed two distribution patterns in the diploid range. The first was oblique zonal cluster (OZC) with the second high concentration in the middle part of it, suggesting mixed proliferation with stimulated reactive lymphocytes, and the second was the high concentration in the lower region of the NDS with some cells corresponding to the growth fraction. In large cell-dominated T-zone lymphomas and ATLL pleomorphic large cell type, the third decreasing pattern in the cell density from the lower part of the OZC to its upper part was found upto the hypertetraploid range. The wide distribution on DNS and giant cells with aneuploid high DNA content were found only in the pleomorphic large cell type and the pleomorphic medium-sized and large cell type of ATLL. The T-immunoblastic type of EPTL showed the third pattern and the pleomorphic large cell type of EPTL, characteristic in the clear cytoplasm, showed the second pattern.

Cell Nucleus↗
PubMed1987

Histopathology and immunohistochemistry of peripheral T cell lymphomas: a proposal for their classification.

Based on the results of histological and immunohistochemical observations of a large number of peripheral T cell lymphomas from China, England, Germany and Japan, histological and cytological morphology were correlated with immunophenotype, aetiological association with HTLV-1, and clinical behaviour to produce a working classification of the T cell lymphomas. This classification, based mainly on cytological criteria, divides the peripheral T cell lymphomas into tumours of low grade and high grade malignancy. Adult T cell lymphoma/leukaemia (ATLL) is caused by HTLV-1 and belongs chiefly to the high grade category. Some tumours are characterised by an admixture of other cells (epithelioid cells, follicular dendritic cells, etc) and structures (high endothelial venules, follicles), which may indicate the secretion of lymphokines by the tumour cells. Clear cells seem to be specific for T cell lymphomas and may occur in various types of peripheral T cell lymphoma.

Adult↗
PubMed1987

Effect of L-threo-3,4-dihydroxyphenylserine (L-DOPS), an immediate precursor of norepinephrine, on the cerebral blood flow in rats.

L-threo-3,4-Dihydroxyphenylserine (L-DOPS), a norepinephrine (NE) precursor, 3 mg/kg, i.v., increased the cerebral blood flow (CBF) in both the striatum and hippocampus as well as the mean arterial blood pressure (MABP) in urethane-anesthetized rats, as NE infusion did. The L-DOPS induced increase in CBF was inhibited by benserazide (3 mg/kg/hour), a peripheral aromatic L-amino acid decarboxylase inhibitor, and propranolol (3 mg/kg, i.p.), a beta-adrenoceptor blocker as well. These results suggest that the effects of L-DOPS may be attributed to the action of NE formed from L-DOPS, and the action may be mediated by stimulation of beta-adrenoceptor.

Animals↗
PubMed1987

Follicular fluid constituents influencing spontaneous maturation of cultured mouse oocytes.

Different concentrations of cyclic adenosine 3',5'-pyrophosphate (cAPP), adenosine, hypoxanthine, 17 beta-estradiol and testosterone were tested to determine their effect on spontaneous germinal vesicle breakdown (GVBD) in mouse oocytes. Individually, these compounds at concentrations of 200 microM or less, had no or minimal inhibitory effect on the spontaneous GVBD of mouse oocytes. Dibutyryl 3',5' cyclic adenosine monophosphate (dbcAMP) at a concentration of 50 microM or higher blocked GVBD but had no effect at concentrations of 20 microM or less. With dbcAMP at a concentration of 20 microM, cAPP blocked GVBD at a concentration of 10 microM. To affect inhibition of GVBD with adenosine, 17 beta-estradiol and testosterone and with hypoxanthine, concentrations of 100-200 microM and 500 microM, respectively, were required. In conclusion cAPP is the most potent compound among those tested in blocking spontaneous GVBD of mouse oocytes when combined with dbcAMP.

Adenosine↗
PubMed1987

Hen ovarian factors influencing neovascularization in mice.

Factors influencing neovascularization were separated from hen ovarian extracts. The lyophilized materials of extracts embedded in ethylenevinylacetate copolymer (Elvax 40) were implanted on the lateral wall of the sheath of M. rectus abdominis in mice. These implants induced inflammation and neovascularization in both a dose and time-dependent manner. Inflammation and neovascularization were characterized by invasion of blood cells and by capillary development into the tissue surrounding the implant. The acid mucopolysaccharide fraction of the extracts and .5 M NaCl fraction of the acid mucopolysaccharide fraction separated by a column of Dowex 1-X2 (Cl-form) showed strong neovascularizing activity without inducing severe inflammation. Results suggest that acid mucopolysaccharides are involved in neovascularization in hen ovaries.

Abdominal Muscles↗