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Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 433 records · Page 24Linked to original sources
PubMed1994

Marked improvement of diabetic diarrhea with the somatostatin analogue octreotide.

Somatostatin and its long-acting analogue octreotide have been used in various diarrheal disorders, including neoplastic and nonneoplastic diseases of the gastrointestinal tract. In two insulin-dependent diabetic patients with autonomic neuropathy and chronic steatorrheic diarrhea refractory to conventional medications, subcutaneous administration of octreotide markedly improved the volume and frequency of stools in both patients. This change was accompanied by a clear improvement in their rapid gastrointestinal tract transit times. The treatment also greatly improved their orthostatic hypotension. No adverse effects of octreotide were observed after treatment for 7 months in one patient and 2 months in the other.

Adult↗
PubMed1994

Formation of sheared G:A base pairs in an RNA duplex modelled after ribozymes, as revealed by NMR.

The thermal stability and structure of an RNA duplex, r(GGACGAGUCC)2, the base sequence of which was modelled after both a hammerhead ribozyme and a lead ribozyme, were studied by CD and NMR. We previously demonstrated that the corresponding DNA duplex, d(GGACGAGTCC)2, formed unique 'sheared' G:A base pairs, where an amino proton, instead of an imino proton, of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head' (Nucleic Acids Res. (1993) 21, 5418-5424). CD melting profiles showed that the RNA duplex is thermally more stable than the corresponding DNA duplex. NMR studies revealed that sheared G:A base pairs are formed in the RNA duplex, too, although the overall structure of the RNA is the A form, which differs from the B form taken on by the corresponding DNA. A model building study confirmed that sheared G:A base pairs can be accommodated in the double helical structure of the A form. A difference between the RNA and DNA duplexes in the stacking interaction involving G:A mismatch bases is also suggested. The demonstration that sheared G:A base pairs can be formed not only in DNA but also in RNA suggests that this base pairing plays an important role regarding the RNA structure.

Adenine↗
PubMed1994

Inhibition of type-1 plasminogen activator inhibitor production by antisense oligonucleotides in human vascular endothelial and smooth muscle cells.

We have hypothesized that type-1 plasminogen activator inhibitor (PAI-1) may exacerbate accumulation of extracellular matrix in atheroma by inhibiting local generation of plasmin and intramural proteolysis. Thus, suppression of PAI-1 expression would decrease atherogenesis. To inhibit expression of PAI-1 in cultured human umbilical vein endothelial and aortic smooth muscle cells, a 20-base antisense phosphorothioate oligonucleotide targeting specific sequences in the 3'-untranslated region of the PAI-1 gene was used. Studies with 32P-labeled oligomers verified stability in media. Secretion of PAI-1 protein assayed by enzyme-linked immunosorbent assay declined specifically and dose-dependently in cells exposed to the antisense oligonucleotide treated under basal conditions and after stimulation of PAI-1 expression with transforming growth factor beta (0.5 ng/ml for endothelial cell, 5 ng/ml for smooth muscle cell). Inhibition of expression was confirmed by immunoprecipitation of 35S-labeled PAI-1 and was paralleled by decreased steady-state levels of PAI-1 mRNA (Northern blots). Decreased PAI-1 synthesis was accompanied by augmentation of cell-associated plasmin activity. Thus, the antisense oligonucleotide down-regulated PAI-1 elaboration, an approach that may be useful in limiting obstructive vascular lesions.

Base Sequence↗
PubMed1994

Overexpression of plasminogen activator inhibitor type-1 in senescent fibroblasts from normal subjects and those with Werner syndrome.

We previously reported that plasminogen activator inhibitor type-1 (PAI-1) mRNA was present at higher steady-state levels in prematurely senescent fibroblasts derived from a subject with Werner syndrome (WS) compared to early passage (EP) fibroblasts from an age-matched normal subject (Murano et al., 1991, Mol. Cell. Biol. 11:3905-3914). To explore the generally of this phenomenon with respect to chronological age of donor (in vivo aging) and the late-passage (LP) or senescent phase of the fibroblast replicative lifespan, we assayed PAI-1 mRNA in cells and PAI-1 antigen in medium conditioned by 20 normal fibroblast strains at EP and LP and six WS strains during their curtailed replicative lifespans. The lowest accumulations of PAI-1 were found in medium conditioned by fetal and newborn cells with a shallow but progressive rise seen in postnatal cells from normal donors of increasing chronological age. With few exceptions, normal LP fibroblasts showed increased PAI-1 accumulations in medium compared to their EP counterparts. Conditioned medium from four of the six WS strains showed PAI-1 accumulations that were significantly higher than the media of any normal controls at EP and LP. PAI-1 mRNa levels were generally commensurate with the cumulative amount of PAI-1 in the medium but the frequent exceptions indicate that translational and post-translational mechanisms also regulate PAI-1 output. The augmentation in PAI-1 output of fibroblasts as a direct function of chronological age and during in vitro senescence suggests that PAI-1 may play an important role in the reduced capacity for wound healing and the increasing tendency to thrombogenesis and atherogenesis seen during biological aging and in particular in persons with Werner syndrome.

Adult↗
PubMed1994

Pathogenetic changes in the lung bud of mutant rats with heritable pulmonary lobation anomalies.

The present study aimed at investigating pathogenesis of pulmonary lobation anomalies in fpl/fpl mutant rats. Day 12-15 embryos were first examined for pulmonary lobation. Lung serial sections were then made and examined for bronchial branching and distribution of extracellular matrices (ECMs). The lung buds of both fpl/fpl embryos and their phenotypically normal fpl/+ littermates were formed as bilateral protrusion of the foregut on gestation day 12. In fpl/+ embryos, three processes appeared on the right lung bud on day 13, and fissures were completely formed by day 14. In fpl/fpl embryos, the right lung bud had no clear process on gestation day 13, and fissures were not formed on day 14 and thereafter, with the exception of incomplete separation between the cranial and middle lobes. Histological observation revealed that the right main bronchial bud of fpl/+ embryos ramified all lobar bronchial buds by gestation day 13. ECMs, a borderline between endodermal bronchial buds and surrounding mesenchyme, disappeared at the distal end of each lobar bronchial bud. By contrast, in fpl/fpl embryos, the right main bronchial bud did not ramify the middle and intermediate lobar bronchial buds at its lateral and ventral portions, but swelled on gestation day 13. It was covered with ECMs at the lateral side but not at the ventral region, from which the middle and intermediate lobar bronchial buds arose on gestation day 14. These observations suggest that altered distribution of ECMs causes branching abnormalities of the lobar bronchial buds and subsequent lobation anomalies in fpl/fpl embryos.

Animals↗
PubMed1994

Exercise therapy in Japan.

The purpose of this report is to outline the exercise therapy of diabetes mellitus that has been administered in Japan during the past 10 years, with special emphasis on the results of studies on metabolic effects as well as on practical aspects of exercise therapy. The studies on the response to exercise clarified neuroendocrine mechanisms involved in the regulation of carbohydrate and fat metabolism in exercise and provided a basis for the indication of exercise therapy in view of the pre-existing metabolic abnormalities. Concerning the training effects, changes of insulin sensitivity have been chiefly studied in relation to metabolic improvement by physical training using the insulin clamp method. The improvement of glucose and lipid metabolism obtained during the training program, consisting of fast walking or jogging corresponding to 40-60% of predictive VO2 max for 30-60 min daily, was suggested to be related to improved insulin sensitivity in patients with NIDDM. Intensive studies have been made on exercise programs, and medical checks and guidelines for exercise prescription have been provided. Aerobic exercises with stretching and low-level callisthenics are recommended, and the usefulness of a multi-stage exercise loading test and the necessity of self-monitoring of blood glucose are stressed for the successful management of exercise therapy.

Diabetes Mellitus↗
PubMed1994

Increased intramural expression of plasminogen activator inhibitor type 1 after balloon injury: a potential progenitor of restenosis.

OBJECTIVES: This study was performed to determine whether altered gene expression of plasminogen activator inhibitor type 1 (PAI-1) occurs within the arterial wall after experimentally induced balloon injury. BACKGROUND: PAI-1, known to inhibit fibrinolysis in the circulation and to be present within atherosclerotic vessels, may influence proteolysis in the arterial wall and neointimal formation after angioplasty. METHODS: In rabbit carotid arteries subjected to balloon injury, both PAI-1 gene and protein expression were assayed sequentially with the use of Northern blotting, in situ hybridization and immunohistochemical studies. RESULTS: In uninjured, normal vessels PAI-1 messenger ribonucleic acid (mRNA) was not detectable by Northern blotting or in situ hybridization. However, injury was followed within 3 h by increases in PAI-1 mRNA (3.2 kb) of 5.9-fold compared with that in contralateral control carotid arteries (Northern blots). PAI-1 mRNA was detectable by in situ hybridization early after injury first in adventitia; after 24 h it was particularly prominent in the media. From 1 to 4 weeks after injury it was consistently detectable and was localized in neointimal vascular smooth muscle and endothelial cells at a time when neointimal thickening was marked. Cells of both types exhibited PAI-1 protein detected immunohistochemically. In vessels maintained in organ culture after balloon injury in vivo, sustained increases in PAI-1 activity appeared in conditioned media as well. CONCLUSIONS: Our results indicate that balloon injury simulating angioplasty in patients induces intramural expression of PAI-1 in vascular smooth muscle and endothelial cells. The decreased cell surface fibrinolytic activity likely to result from the increased PAI-1 expression may initiate or exacerbate mural thrombosis. Accordingly, excessive stimulation with clot-associated mitogens may stimulate vascular smooth muscle cell proliferation, which, coupled with increased accumulation of extracellular matrix attributable to decreased plasmin-mediated degradation, may contribute to restenosis.

Animals↗
PubMed1994

Stimulation of migration of human aortic smooth muscle cells by vitronectin: implications for atherosclerosis.

OBJECTIVE: Migration of smooth muscle cells into the neointima has been implicated in atherogenesis. Vitronectin, a serum factor that promotes cell spreading and attachment, accumulates in atherosclerotic human tissues. The aim of this study was to determine the role of vitronectin and its receptor (integrin alpha V beta 3) in migration of smooth muscle cells. METHODS: Human aortic smooth muscle cell migration was studied in modified Boyden chambers. Expression of vitronectin receptor was determined by northern blotting of receptor mRNA and immunoprecipitation of receptor protein. RESULTS: Vitronectin dose dependently increased smooth muscle cell migration by an amount comparable to that induced by platelet derived growth factor, (PDGF)-BB. Antiserum to alpha V beta 3 diminished vitronectin driven migration. Northern blot analysis showed low constitutive expression of alpha V and beta 3 mRNA by smooth muscle cell and rapid induction with transforming growth factor beta (TGF-beta) and thrombin. Immunoprecipitation confirmed increased synthesis of the alpha V beta 3 vitronectin receptor complex by TGF-beta or thrombin. Smooth muscle cells pretreated with TGF-beta or thrombin showed increased vitronectin driven migration. cAMP suppressed induction of migration, but inhibition of protein kinase C increased it. CONCLUSIONS: These results show that vitronectin-induced human aortic smooth muscle cell migration is mediated by alpha V beta 3 vitronectin receptor and expression of the receptor is induced by TGF-beta and thrombin, which in turn induce vitronectin driven, vitronectin receptor modulated smooth muscle cell migration.

Arteriosclerosis↗
PubMed1994

Asparagine-linked carbohydrate of Penicillium notatum phospholipase B.

The asparagine-linked sugar chains of phospholipase B from Penicillium notatum were released by hydrazinolysis. The carbohydrate components were re-N-acetylated and then reductively aminated with 2-aminopyridine. The pyridyl-aminated derivatives were analyzed by size-fractionation and reverse-phase HPLC. The results indicated that the enzyme contains only one kind of oligosaccharide. The carbohydrate was purified by HPLC, and then subjected to NMR and MS analyses for determination of its structure. Based on the results, the structure was determined to be as follows. [sequence: see text]

Asparagine↗
PubMed1994

Role of Ca2+ in the binding of phospholipase A2 with a monomeric substrate and with its amide-type analog.

Effects of Ca2+ on the kinetic parameters for the hydrolysis of monodispersed 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (diC6PC), catalyzed by Group I phospholipases A2 (PLA2s) from Pseudechis australis, Naja naja atra, and bovine pancreas and by Group II enzymes from Vipera russelli russelli, Agkistrodon halys blomhoffii, and Trimeresurus flavoviridis, were studied by the pH-stat assay method at 25 degrees C, pH 7.5-8.2, and an ionic strength of 0.1 or 0.2 in the absence or presence of an amide-type substrate analog, 2-dodecanoyl-amino-1-hexanol-phosphoglycol. The binding of genuine substrate to the Group II enzymes and that of its analog to the Groups I and II enzymes were markedly facilitated by the binding of Ca2+ to the enzymes. On the other hand, the binding of genuine substrate to the Group I enzymes was found to be independent of the Ca2+ binding. The former result suggests that the structures of the Group II enzyme-genuine substrate complexes and both types of enzyme-analog complexes are generally stabilized by the Ca2+ binding, whereas the latter indicates that the structures of the Group I enzyme-genuine substrate complexes are already similar to those of their Ca2+ complexes and that, therefore, these enzyme-substrate interactions are independent of the Ca2+ binding.

Amides↗
PubMed1994

Transitional cell carcinoma of the fallopian tube: a light and electron microscopic study.

Carcinomas other than adenocarcinomas are extremely rare in the fallopian tube. We report a case of a malignant neoplasm of the fallopian tube with histological features of transitional cell carcinoma that presumably arose from an extraluminal region of the tube. A 57-year-old postmenopausal woman with vaginal bleeding was found to have a left adnexal tumor. Exploratory laparotomy revealed a left tubal tumor with a metastatic nodule on the rectal surface. Histologically, the tumor surrounded the lumen of the left fallopian tube and was composed of cells with "coffee-bean"-like nuclei arranged in solid nests without keratinization. No abnormalities were found in the right tube, ovaries, or uterus. Electron microscopy revealed the tumor cells to have nuclei with deep nuclear indentations, cytoplasmic tonofilaments, and intercellular spaces with prominent interdigitations of the cell membrane. In addition, several tumor cells with protruding microvilli formed abortive lumina. These histological and ultrastructural features were consistent with the diagnosis of transitional cell carcinoma.

Carcinoma, Transitional Cell↗
PubMed1994

Immunohistochemical analysis of the peritoneum adjacent to endometriotic lesions using antibodies for Ber-EP4 antigen, estrogen receptors, and progesterone receptors: implication of peritoneal metaplasia in the pathogenesis of endometriosis.

This study was designed to investigate whether or not the pelvic peritoneum exhibits a metaplastic process into müllerian-type epithelium using a marker for epithelial differentiation (Ber-EP4 antigen) and markers that indicate müllerian differentiation (estrogen receptors and progesterone receptors). The peritoneum and/or ovarian surface epithelium adjacent to endometriotic lesions were obtained from 24 patients with endometriosis at operation, and peritoneum and ovarian surface epithelium without any lesions were also obtained from control patients without endometriosis. The specimens were immunohistochemically analyzed using antibodies for epithelial antigen Ber-EP4, estrogen receptor (ER), and progesterone receptor (PR) on frozen sections. Normal peritoneal mesothelium showed negative staining for Ber-EP4, ER, and PR. The mesothelium of the peritoneum adjacent to the endometriotic lesions showed focal positivity for Ber-EP4, ER, and PR. Several cases of ovarian surface epithelium from normal control ovaries and ovaries adjacent to endometriotic lesions also showed focal positivity for Ber-EP4, ER, and PR. Stromal cells accompanying these foci were sporadically positive for ER and/or PR but negative for Ber-EP4. Focal expression of Ber-EP4, ER, and PR in the mesothelium of the peritoneum and the ovarian surface epithelium adjacent to endometriotic lesions suggests that mesothelium possibly acquires characteristics of epithelial as well as müllerian-type nature. These results support an existence of a metaplastic process of the peritoneal mesothelium in the pathogenesis of endometriosis. The more frequent Ber-EP4 positivity in normal ovarian surface epithelium compared to normal peritoneal mesothelium also suggests a fundamental difference in these tissues that may be related to the greater prevalence of epithelial neoplasms arising in ovarian tissue.

Adult↗
PubMed1994

Lack of degradation of antithrombin III by tissue-type plasminogen activator or plasmin.

BACKGROUND: Coronary thrombolysis is an established initial approach in the treatment of acute transmural myocardial infarction. However, conjunctive anticoagulation regimens are often suboptimal. Heparin is the only intravenously administered anticoagulant approved by the USA Food and Drug Administration commonly used for this purpose. Unfortunately, it exhibits potential limitations that may either predispose arteries to reocclusion or result in failure of initial recanalization. This study was designed to determine whether consumption of heparin cofactor, antithrombin-III (AT-III), compromises the efficacy of heparin in the setting of pharmacologic fibrinolysis and, if so, whether this degradation or inactivation is directly attributable to the effects of tissue-type plasminogen activator (t-PA) or plasmin in the blood stream. METHODS: AT-III was assayed by Western blotting and with a microlatex particle immunoassay in buffer, plasma, or in vivo after exposure to plasmin or t-PA. RESULTS: Neither t-PA (1-10 micrograms/ml) nor plasmin (2 microM) appeared directly to degrade AT-III in purified systems or in plasma. However, levels fell in some patients treated with t-PA, albeit a minority, in association with intense thrombosis, as reflected by failure of recanalization. CONCLUSION: Our results demonstrate that AT-III is not degraded directly by t-PA or plasmin. They suggest that intense, ongoing thrombosis is responsible for consumption of AT-III in some patients and support the hypothesis that diminution of AT-III is a manifestation rather than a cause of inadequate anticoagulation.

Administration, Oral↗
PubMed1994

Augmented systemic immunity in mice implanted with tumor necrosis factor-alpha gene-transduced Meth-A-cells.

Syngeneic BALB/c mice bearing methylcholanthrene-induced fibrosarcoma (Meth-A) cells transduced with a tumor necrosis factor (TNF) gene showed a longer life span and tumor regression as compared with mice carrying TNF-non-producing Meth-A cells. To elucidate the mechanism of the reduced tumorigenicity of TNF-producing Meth-A, we compared systemic immune responses between mice bearing high TNF producer (C5) and unmodified Meth-A cells (M0). The results indicated that the cytotoxic activity of lymphokine-activated killer cells (LAK) induced from spleen cells of mice bearing C5 was higher against both M0 and C5 than that of LAK from mice bearing M0. Also, C5 was more sensitive to LAK induced from spleen cells of C5- and M0- bearing mice than M0. We also found that cytotoxic T lymphocyte from spleen cells of mice transplanted with C5 was more cytotoxic to M0 than that from mice with M0. In addition, the population of Lyt2 (CD8)-positive T cells was higher in freshly isolated spleen cells of mice transplanted with C5 than from mice with M0. Finally, we observed a higher expression of MHC class 1 antigen on C5 than on M0. These observations suggest that the augmented host systemic immunity in mice carrying TNF gene-modified Meth-A cells is one of the mechanisms of the reduced tumorigenicity of C5 and that the increased systemic immunity can be ascribed to the increased immunogenicity of the tumor cells. Thus, the use of TNF gene-modified tumor cells as vaccines appears to be promising for therapeutic and/or prophylactic application.

Animals↗
PubMed1994

Characterization of CA125 glycoprotein using 3 monoclonal antibodies with different specificities.

CA125 and CA130 in various tissues were characterized using the monoclonal antibodies OC125, 130-22, and 145-9. CA125 and CA130 were eluted in the same fraction in 130-22 affinity chromatography. A sandwich immunoradiometric assay using these antibodies in combination was established. When the solid phase of the assay was changed from OC125 to 145-9, the amount of 125I-OC125 that reacted with CA125 in the amnion increased more than that in other samples. On SDS-PAGE, CA125 and CA130 epitopes in the amnion migrated to different positions. These results indicate that CA125 and CA130 are located on different subunits of the same glycoprotein, and that their synthesis is regulated differently in various tissues.

Amnion↗