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Biomedical subjects

E Sato

Publications and source records attributed to E Sato.

At least 415 records · Page 23Linked to original sources
PubMed1985

Modulation of oocyte maturation by cyclic adenosine 3', 5'-pyrophosphate.

The germinal vesicle (GV) of follicle-enclosed oocytes in mammals remains arrested at the dictyate state of meiosis. Upon releasing the oocytes from the follicles, the meiotic process resumes, leading to dissolution of the GV (GVBD), suggesting that factors in the follicular fluid sustain the meiotic arrest of oocytes. In the present study the spontaneous resumption of meiosis was blocked by the addition of cyclic adenosine 3', 5'-pyrophosphate (cAPP) plus dibutyryl cyclic adenosine 3',5'-monophosphate (dbcAMP), at final concentrations of 25 and 50 microM, respectively. These compounds were ineffective when added separately at these concentrations. None of the other related compounds tested with dbcAMP blocked GVBD. Bovine follicular fluid (BFF) was analyzed for inhibitors of GVBD. BFF was extracted with 70% ethanol and the ethanolic extract chromatographed on Dowex 1-X8 column. The fraction eluted with 0.1 N HCl markedly inhibited GVBD of isolated mouse oocytes in combination with dbcAMP. The active BFF substance and cAPP block spontaneous GVBD of mouse oocytes and may be related substances. The present study supports the thesis that meiotic arrest at the dictyate stage in oocytes is sustained by factors present in follicular fluid and may act in association with cAMP.

Animals↗
PubMed1985

Adsorption and desorption of polydimethylsiloxane, PCBs, cadmium nitrate, copper sulfate, nickel sulfate and zinc nitrate by river surface sediments.

An investigation into the adsorption and desorption of polydimethylsiloxane, PCBs, cadmium nitrate, copper sulfate, nickel nitrate and zinc nitrate by river sediments was carried out using either a flow-through system or a semi-static system. The material balance in the sediment compartment could be explained by the equation, dCs/dT= K1Cw-K2Cs. The adsorption rate constants (K1), desorption rate constants (K2) and concentration factors (K1/K2) were calculated. For hydrophobic chemicals, the K1's were independent of water solubility, but the K2's were relatively related to water solubility. For both hydrophobic chemicals and heavy metals, the concentration factors per fraction organic carbon were similar to the soil sorption coefficients (Koc), expressed on a organic carbon basis.

Adsorption↗
PubMed1985

Lectin histochemistry in a case of ulcerative colitis complicating rectal carcinoma.

The large bowel from a patient with ulcerative colitis complicating a rectal carcinoma was histochemically investigated by using two lectins; Ulex europaeus agglutinin-I (UEA-I) and peanut lectin (PNA). Much UEA-I binding glycoantigen and PNA binding glycoantigen appeared in the carcinoma and dysplastic lesion whereas only a small amount of both antigens was found in the non-dysplastic regenerating epithelium. Consequently, a very sharp contrast between the dysplastic lesion and non-dysplastic regenerating epithelium was demonstrated by the lectin staining.

Adenocarcinoma↗
PubMed1985

Nuclear changes in colo-rectal epithelium with special reference to nuclear inclusions in carcinoma, dysplasia, adenoma and Peutz-Jeghers polyps.

The incidence and types of unusual nuclear structures (UNS) were examined based on the observation of randomly photographed 1,919 nuclei in total from the normal epithelium, dysplasia, Peutz-Jeghers type polyp, adenoma and carcinoma of the large bowel. These nuclear structures were classified as filamentous, granular and vesicular inclusions, and invaginated structures were also taken into consideration. Although all types of UNS were found in the normal epithelium, carcinoma cells had the most numerous UNS, especially of the invaginated type. The possible process of nuclear inclusion (NI) formation was discussed in connection with malignant transformation of colo-rectal epithelial cells.

Adenoma↗
PubMed1985

Interaction of 14 C-gossypol with human sperm.

Gossypol, a bis-sesquiterpene, suppresses spermatogenesis and inhibits sperm motility. The direct interaction of gossypol with human sperm was investigated. Conditions influencing the interaction of 14c-gossypol (radiolabeled on the aldehyde group with specific activity of 3.33 x 10 5 dpm per micromole) with human sperm reached saturation rapidly. Within 1 minute of exposure of motile sperm to 10 uM radiolabeled gossypol at 37 degrees Centigrade, the cincorporation of 14c-gossyol was 17 at 35% at densities of 2.5 x 106 and 8.6 x 106 per ml, respectively. Immobile sperm prepared by heating at 60 degrees Centigrade for 10 minutes incorporated the same amount of 14c-gossypol as motile sperm. Uptake of 14c-gossypol was slightly greater at 37 degrees Centigrade than at 4 degrees Centigrade, and under acidic conditions. To identify the sperm membrane components interacting with gossypol radiolabeled sperm were treated with the following 3 solutions to solubilize the membrane proteins: 0.1% Triton X-100; 1 M urea, 5 mM EDTA in 19mM Tris-HC1, pH 8.3; and 20% sodium doydecyl sulfate (SDS), 0.1M 20mercaptoethanol. The amount of radiolabeled proteins solubilized with respective media were 11, 23, and 67% with specific activities of 1.8 x 103, 2.1 x 105, and 0.3 x 103 cpm per mg protein. The radiolabeled substances solubilized with SDS, mercaptoethanol reagent were separated by gel filtration on Sephadex G-100 column. 3 peaks of radioactivities corresponding to molecular weights of approximately 100, 35, and 25 KD were eluted. The highest radioactivity was found with the 100 KD fraction. The interaction of gossypol with sperm membrane proteins is an early event, followed by inhibition of sperm motility.

Contraception↗
PubMed1985

Carcinoma-specific Ulex europaeus agglutinin-I binding glycoproteins of human colorectal carcinoma and its relation to carcinoembryonic antigen.

Glycoproteins binding to Ulex europaeus agglutinin-I (UEA-I) lectin, which recognizes the terminal alpha-L-fucose residue, were analyzed in 18 cases of human colorectal carcinoma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by the Western blotting method. In the distal large bowel (descending and sigmoid colon and rectum), high-molecular-weight glycoproteins binding to UEA-I existed in carcinoma tissue but not in normal mucosa. In the proximal large bowel (ascending and transverse colon), high-molecular-weight glycoproteins binding to UEA-I were found both in normal mucosa and in carcinoma tissue, whereas those from the carcinoma tissue had an apparently lower molecular weight as compared to the weight of those from the normal mucosa. Thus there is a biochemical difference in UEA-I binding glycoproteins between the normal mucosa and the carcinoma tissue, although in our previous histochemical study no difference was observed in UEA-I binding glycoproteins of the proximal large bowel between the carcinoma tissue and the normal mucosa. Furthermore, carcinoembryonic antigen from the carcinoma tissue was found to have the same electrophoretical mobility as the UEA-I binding glycoproteins.

Aged↗
PubMed1985

Juvenile secretory carcinoma and juvenile papillomatosis.

Two cases of juvenile secretory carcinoma associated with juvenile papillomatosis are reported. One patient's disease was initially diagnosed at the age of 13 and she died 12 years later with extensive metastases. The contralateral breast at autopsy showed findings indicative of juvenile papillomatosis. The second case is that of an 18-year-old girl who had multiple juvenile secretory carcinomas in the left breast associated with juvenile papillomatosis.

Adolescent↗
PubMed1984

Hormonal effects on the development changes of mouse small intestinal glycolipids.

The composition of intestinal glycosphingolipids during normal and hormone-perturbed development was investigated. The concentrations of glycosphingolipids of mouse small intestine were affected by the injection of thyroxine or cortisone during suckling and weaning periods. GDla was reduced by the hormonal treatment among major gangliosides, GM3, GM1 and GD1a, of mouse small intestine during the suckling period. In contrast, asialo GM1 was precociously produced by the treatment, which scarcely found in control suckling mouse small intestine. The results showed that these hormones were related to developmental alteration of small-intestinal glycolipids.

Aging↗
PubMed1984

Forskolin and mouse oocyte maturation in vitro.

Oocytes isolated from mature follicles undergo spontaneous maturation when cultured in vitro. Forskolin, an adenylate cyclase stimulator, inhibited resumption of meiosis of cumulus-free mouse oocytes in vitro. Germinal vesicle breakdown (GVBD) was prevented in more than 85% of the oocytes treated by forskolin at concentrations of 20 micrograms/ml and higher. The inhibiting effect of forskolin was dose-dependent and reversible. FSH, LH, FSH plus LH, estrogen, progesterone, and estrogen plus progesterone did not reverse the block induced by forskolin in cumulus-free and cumulus-enclosed oocytes. The present results suggest that intracellular cAMP may play a role in the regulation of oocyte maturation.

Animals↗
PubMed1984

New fluorogenic, photoactivable, heterobifunctional crosslinking thiol reagents.

Properties of newly synthesized crosslinking reagents (ACM) and their applications to proteins are studied (ACM is the abbreviation for a series of photoactivable and heterobifunctional crosslinking thiol reagents, each of which has two reactive groups, maleimide and azide). These reagents bind specifically to the sulfhydryl residues of proteins in the first reaction step. Upon photoactivation, the azide group of the coumarin ring reacts with side or main chains of the proteins, and thus intra- or intermolecular crosslinking can be elicited. In addition, the coumarin moiety of the reagents becomes highly fluorescent after photolysis. Therefore, the crosslinking products can be detected by fluorometry with high sensitivity in the pattern of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Reaction of ACM with rabbit muscle aldolase led to extensive crosslinking between subunits of the enzyme and maximally 25% of the total subunits were found to be crosslinked to the dimer.

Acetylcysteine↗
PubMed1984

Bioconcentration potential of polydimethylsiloxane (PDMS) fluids by fish.

The water solubilities (S), octanol/water partition coefficients (KOW) and bioconcentration factors (BCF) of four polydimethylsiloxane (PDMS) fluids covering a wide range of molecular weight were measured. It is shown that a previously described correlation between S and KOW for organic chemicals may be invalid for PDMS fluids; an alternative correlation is proposed. Some PDMS fluids tend to have a bioconcentration potential in silver carp.

Animals↗
PubMed1984

A factor from bovine granulosa cells preventing oocyte maturation.

A factor preventing spontaneous dissolution of germinal vesicle (GVBD) of mouse oocytes in vitro was isolated from bovine granulosa cells and designated as granulosa cell factor (GCF). Granulosa cells from medium sized (2-5 mm) follicles were suspended in 10 mM Tris-HCl buffer, pH 8.3, containing 1 M urea and 5 mM EDTA. GCF was separated from the extract by gel filtration on Sephadex G-25 column. The molecular weight (Mr) of GCF was estimated to be less than 6,000 daltons. Oocytes treated with GCF and resuspended in control medium resumed GVBD. The partially purified GCF lost GVBD-preventing activity when digested with pronase but retained its activity when treated with DNase, RNase, or glycosidase. GCF was stable to heating at 100 degrees C for 15 min, not absorbed by charcoal, and did not bind to Concanavalin A-Sepharose 4B. The present findings suggest that GCF is a heat-stable polypeptide and its action is reversible.

Animals↗
PubMed1984

A comparative study on the immunolocalization of keratin and myosin in salivary gland tumors.

Surgical specimens of the salivary gland tumor were studied by immunohistochemical techniques using the anti-keratin antibody and the anti-myosin antibody. In the normal tissue, keratin was localized predominantly in the duct epithelial cells and myosin in the myoepithelial cells. According to the immunohistochemical staining patterns, the tumors were able to be divided into two groups: one group consisted of pleomorphic adenoma, adenoid cystic carcinoma, and adenocarcinoma which showed a mixture of keratin- and myosin-positive cells, respectively, mimicking the structures of the intercalated duct; the other comprised monomorphic adenoma and mucoepidermoid tumor which disclosed keratin-positive cells predominantly, resembling the constituent of the excretory duct. These results were mostly consistent with the "bicellular theory" that the salivary tumors generate from the intercalated duct reserve cells and the excretory duct reserve cells.

Adenocarcinoma↗