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Biomedical subjects

E Sato

Publications and source records attributed to E Sato.

At least 325 records · Page 18Linked to original sources
PubMed1991

Reduction of mono(ADP-ribosyl)ation of 20 kDa protein with maturation in rat testis: involvement of guanine nucleotides.

When the homogenate prepared from immature rat testes was incubated with [32P]NAD, several proteins (90, 39 and 20 kDa) were ADP-ribosylated in the absence of bacterial toxins. This observation suggested the existence of an endogenous ADP-ribosyltransferase and substrates. The data that the digested product by phosphodiesterase of ADP-ribosylated 20 kDa protein was 5'-AMP suggested that 20 kDa protein was mono(ADP-ribosyl)ated. In addition, the mono(ADP-ribosyl)ation of 20 kDa protein was enhanced by guanine nucleotides such as GTP, GDP and GTP[gamma S], and decreased by the concentrations of 10 mM Mg2+. In contrast, the incorporation of ADP-ribose moiety from NAD to both 90 and 39 kDa proteins was not changed by guanine nucleotides. On the other hand, mono(ADP-ribosyl)ation of 20 kDa protein was not observed in the homogenate prepared from other tissues of the same rats. Furthermore, we found that mono(ADP-ribosyl)ation of 20 kDa protein was decreased with the maturation of the rats and that an endogenous mono(ADP-ribosyl)transferase and 20 kDa protein were located in the nuclei.

ADP Ribose Transferases↗
PubMed1991

Serum IgG from CBA/K1Jms-lprcg/lprcg mice induces interleukin 3 in an interleukin-3-dependent cell line--possible correlation with lymphadenopathy.

Serum IgG of CBA-K1Jms-lprcg/lprcg (lprcg/lprcg) mice with spontaneous systemic lymphadenopathy supported the proliferation of an IL-3-dependent cell line, FDC-P2/185-4. The lprcg/lprcg IgG induced IL-3 synthesis in FDC-P2/185-4 cells, and cells grew by an autocrine mechanism. There was virtually no time lag between the appearance of lymphadenopathy and an increase of IL-3-inducing activity in the sera. We have previously shown that serum IgG from other autoimmune mice with lymphadenopathy, MRL/Mp-lpr/lpr(MRL/lpr) and C3H/HeJ-gld/gld(C3H/gld), also induces IL-3 synthesis and cell growth in FDC-P2/185-4 cells. Furthermore, neither F1 (lprcg/+) mice between lprcg/lprcg and CBA(-)+/+ nor those (lpr-gld) between C3H-lpr/lpr and C3H/gld showed such IL-3-inducing activity, while those (lprcg-gld) between lprcg/lprcg and C3H/gld showed activity much lower than that of their parental strains but significantly higher than that of normal CBA(-)+/+ mice. This result is consistent with the incidence and degree of lymphadenopathy in these F1 mice. Our results suggest that expression of IgG(s) with cytokine-inducing activity might be controlled by these mutant genes, lpr, gld, and lprcg, and might be related to lymphadenopathy in these mice.

Animals↗
PubMed1991

Application of bimane-peptide substrates to spectrofluorometric assays of metalloendopeptidases.

A spectrofluorometric method for sensitive determination of metalloendopeptidase activity has been developed by using a bimane-peptide containing a tryptophan residue, i.e. 1,7-dioxo-2,5,6-trimethyl-1H,7H-pyrazolo[1,2-alpha]pyrazol-3-yl-methyl- thiomethylcarbonyl-phenylalanyl-tryptophanyl-leucine (Bim-SCH2CO-Phe-Trp-Leu-OH). Such an "intramolecularly quenched" substrate was originally designed for a sensitive assay of angiotensin I converting enzyme (ACE) [Sato, E. et al. (1989) Chem. Pharm. Bull. 37, 145-147]. All the typical metalloendopeptidases tested, such as thermolysin, Pseudomonas aeruginosa (Ps.) elastase, Streptomyces griseus metalloendopeptidases I and II (SGMPI and SGMPII), and alkinonase A, a metalloendopeptidase from Streptomyces violaceorectus, cleaved this substrate strictly at a Phe-Trp bond, leading to a marked increase in fluorescence. Kinetic parameters of the enzymatic hydrolyses of five kinds of analogous bimane substrates were compared to examine how the nature of neighboring amino acid residues on either side of the cleavable bond affects the catalytic efficiency of each of the metalloendopeptidases. Bim-SCH2CO-Phe-Trp-Leu-OH was most efficiently hydrolyzed by all of these enzymes. The use of this substrate made it possible to determine minute amounts of metalloendopeptidases, especially those originating from Streptomycetes (for example, as little as 10 fmol of SGMPII).

Amino Acid Sequence↗
PubMed1991

Experimental odontogenic tumors produced by ethylnitrosourea injections and mechanical injuries.

The present study was carried out to investigate odontogenic tumor induction in the rats by injections of carcinogen N-ethyl-N-nitrosourea (ENU) coupled with incisional wounds. The animals which received local injections of ENU in the region of incisor tooth germ of the right mandible every other day for 19 days after birth coupled with incisional wounding in the same region at 2 and 8 days, developed odontogenic carcinomas. However, the animals which were given local injections of ENU in the region of incisor tooth germ but did not receive incisional wounds, showed no pathologic changes. The animals which received both local injections of physiologic salt solution and incisional wounds in the same manner as mentioned above, did not exhibit any pathologic changes. The present results indicate that local administration of carcinogen ENU coupled with mechanical injuries, namely incisional wounding, caused the production of odontogenic carcinomas in the incisor region of the mandible in rats.

Ameloblasts↗
PubMed1991

Ovarian glycosaminoglycans potentiate angiogenic activity of epidermal growth factor in mice.

Epidermal growth factor (EGF) has been shown to induce capillary proliferation. In the course of our investigation on the interaction of ovarian components with EGF, we observed that partially purified glycosaminoglycans (GAGs) isolated from mouse ovaries enhanced the angiogenic activity of EGF when applied simultaneously to the lateral wall of the sheath of musculus rectus abdominis. Mouse EGF from submandibular glands embedded in Elvax 40 implanting on the musculus rectus abdominis induced neovascularization in a dose-dependent manner. When 0.5 micrograms ovarian GAGs was embedded in the implant with a low amount of EGF that induced only slight neovascularization (0.5 or 1 microgram/implant), the angiogenic activity of the growth factor was markedly enhanced. The active GAG component was isolated by chromatography on Dowex 1-x2. The fraction eluted with 0.5 M NaCl possessed the greatest activity to potentiate the angiogenic activity of EGF. When the reaction mixture of GAGs and EGF was treated with 1% cetylpyridinium chloride, the angiogenic activity was identified with the supernatant. On the other hand, after incubating EGF with 0.5 M NaCl fraction, the angiogenic activity of EGF was identified with the precipitate (GAG fraction) of the cetylpyridinium chloride-treated reaction mixtures. These findings show that ovarian GAGs potentiate the angiogenic activity of EGF by interacting or complexing with EGF.

Abdominal Muscles↗
PubMed1991

Fluorogenic bimane substrates with dabsyl group for endopeptidases; chymotrypsin, collagenase and thermolysin.

It was found that the fluorescence of 9,10-dioxa-syn-3,4,6,7-tetramethylbimane (bimane) can be quenched in the presence of dimethylaminoazobenzensulfonyl (Dabsyl) group. New combination of bimane (fluorophor) and dabsyl group (quencher) was applied to the syntheses of intramolecularly quenched fluorogenic substrates for hydrolytic enzymes. Bimane peptides containing dabsyl group were prepared, and were shown to be useful fluorogenic substrates for the assay of endopeptidases such as chymotrypsin, collagenase and thermolysin.

Bridged Bicyclo Compounds↗
PubMed1991

A putative mouse oocyte maturation inhibitory protein from urine of pregnant women: N-terminal sequence homology with human nonsecretory ribonuclease.

A putative mouse oocyte maturation inhibitory protein was purified from a urine preparation from pregnant women by Sephadex G-100 gel filtration and reverse-phase chromatography on the basis of inhibitory activity of polar body formation of denuded mouse oocytes in culture. Amino terminal sequence analyses showed that residues 5 to 15 of this protein were identical to residues 1 to 11 of human nonsecretory ribonuclease. Furthermore, residues 1 to 4 of this protein were identical to residues -4 to -1, corresponding to part of a signal peptide region of eosinophil-derived neurotoxin, whose mature sequence is identical to nonsecretory ribonuclease. These results indicate that the protein purified as a putative mouse oocyte maturation inhibitory protein from the urine of pregnant women may be a product of an peculiar processing of a nonsecretory ribonuclease precursor.

Amino Acid Sequence↗
PubMed1991

Bimane fluorogenic substrates for microdetermination of angiotensin converting enzyme level in serum.

The fluorescence of 9,10-dioxa-syn-3,4,6,7-tetramethylbimane (bimane) was found to be quenched in the presence of nitrated aromatic amino acid. Bimane peptides containing nitrated amino acid (1a, b) were shown to be useful fluorogenic substrates for the assay of angiotensin I converting enzyme (ACE) from rabbit lung, similar to bimane substrate containing tryptophan (3) previously reported. Among these bimane substrates, substrate 3 was shown to be a potent fluorogenic substrate for microdetermination of the ACE level in human serum.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Association of Epstein-Barr virus with undifferentiated gastric carcinomas with intense lymphoid infiltration. Lymphoepithelioma-like carcinoma.

Some undifferentiated gastric carcinomas with intense lymphoid infiltration have a striking resemblance to nasopharyngeal lymphoepithelioma. The authors identified eight such cases (seven patients from Japan and one from the United States) of undifferentiated gastric carcinoma (lymphoepithelioma-like carcinoma [LELC]) and examined them for Epstein-Barr (EBV) viral sequences using polymerase chain reaction (PCR) and in situ hybridization (ISH) techniques. EBV was detected in seven of the eight cases by PCR, including a lymph-node metastasis. ISH that was performed in six of these cases showed EBV genomes to be uniformly present in the carcinoma cells and not present in the reactive lymphoid infiltrate or normal gastric mucosa. PCR of a polymorphic EBV locus (lymphocyte-determined membrane antigen) showed that a single genotype was present in each gastric LELC, consistent with a clonal process. These findings suggest that some undifferentiated gastric carcinomas are EBV-related and that focal EBV infection occurs before transformation.

Antigens, Surface↗
PubMed1991

[Alterations of Lewis related sugar antigens in gastric atypical epithelial lesions (adenomas or dysplasia) with relation to their malignant changes--an evaluation by follow-up cases].

Alterations of carbohydrate chain antigens were investigated immunohistochemical in relation to histological malignant changes on 62 cases of gastric atypical epithelial lesions (adenomas) which were diagnosed as Group-III at the first biopsy and then followed up more than one year. Among 7 carbohydrate chain antigens which are related to Lewis antigens, sialyl Lex-i antigen showed the most impressive findings; The positivity percentage of the first biopsy specimens of Group-III was 6%, however, it raised to 33% in the final biopsy specimens of Group-IV, 50% in the resected specimens of border-line lesions, and 67% in the resected specimens of carcinomas. The results indicate that there exists a close correlation between malignant change of gastric atypical epithelial lesions and alteration of carbohydrate chain in terms of sialylation.

Adenoma↗
PubMed1991

[Hyponatremia during transurethral resection of the prostate].

In a retrospective study of 222 patients who underwent transurethral resection of the prostate under spinal anesthesia, plasma sodium levels during the operation were examined. The weight of prostate resected, the volume of irrigating fluid used and the duration of the operative procedure influenced the changes in plasma sodium levels. But, these changes were not statistically significant. The rise in central venous pressure values was associated with the absorption of irrigating fluid as evidenced by a drop in plasma sodium. The central venous pressure was monitored in 77 patients. There was a statistically significant correlation between the degree of hyponatremia and the rise in central venous pressure (P less than 0.001). The rise in central venous pressure reflected a change in the patient's cardiovascular status and it was, therefore, possible to treat the hyponatremia quickly and effectively. Central venous pressure monitoring is helpful in determining hyponatremia before it becomes clinically manifest.

Aged↗
PubMed1991

Bleeding ectatic vascular lesion involving the sigmoid colon, endoscopically indistinguishable from angiodysplasia, in an 8-yr-old boy.

An 8-yr-old Japanese boy was hospitalized, complaining of active hematochezia. He was shown to have a cherry-red, blood-oozing area of vascular dilation with mucosal prominence in the sigmoid colon by endoscopy, but had no other mucocutaneous vascular abnormalities. A family history was noncontributory. Under the clinical diagnosis of angiodysplasia of the sigmoid colon, he underwent an elliptical resection of the part, based on the intraoperative endoscopic findings. However, histological examination of the surgical specimen revealed a totally different picture from that seen in angiodysplasia: the thin-walled, markedly ectatic, nontortuous veins with hemorrhage were seen only just below the muscularis mucosae, around which the normal ones were shown to coexist. He has had no rebleeding for the past 3 yr. This lesion is considered to be an isolated congenital visceral telangiectasia involving veins.

Child↗
PubMed1991

[Direct surgical management of aneurysms in the cavernous sinus: a report of 5 cases].

Five patients with aneurysms in the cavernous sinus were treated by direct surgical approach. Two small aneurysms were located in the C3 segment, one small aneurysm was on the primitive trigeminal artery (PTA), and the last two aneurysms were giant ones. The three small aneurysms were discovered incidentally by angiography and the two giant aneurysms presented oculomotor palsy. After ordinary fronto-temporal craniotomy, the two C3 aneurysms were treated through an intradural approach, and the PTA aneurysm and the two giant aneurysms were treated through combined epi- and subdural approach. The three small aneurysms were clipped and the two giant aneurysms were trapped with the reconstruction of ICA by saphenous veins. In all cases the aneurysms were excluded postoperatively, but in one giant-aneurysm case (Case 5) the bypass was occluded postoperatively, but the patient had no permanent neurological deficit. The four patients developed third nerve palsy and one developed fourth nerve palsy which resolved within 3 to 6 months. In one C3-aneurysm case (case i) the patient had loss of vision due to much packing in the medial side of the ICA. All patients were discharged and returned to their usual life. Three cases (case 2, 4, 6) are presented here and the problems of direct surgical management of aneurysms in the cavernous sinus are discussed with the related literature.

Adult↗