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Biomedical subjects

S Fujii

Publications and source records attributed to S Fujii.

At least 325 records · Page 18Linked to original sources
PubMed1997

Thioredoxin expression in the human endometrium during the menstrual cycle.

Human thioredoxin, a cellular disulphide reducing protein, is known to be secreted by some types of cells and to display unique extracellular activities including modulation of cytokine actions and protection of the cell against damage from oxidative stress. This study has been undertaken to investigate the pattern of expression and tissue distribution of thioredoxin in human endometrium during the menstrual cycle. Immunohistochemical studies showed increased thioredoxin immunoreactivity in the glands of the secretory phase compared to those of the proliferative phase. Although the staining of thioredoxin was relatively intense in predecidual stromal cells, the most prominent staining of thioredoxin was present in both glands and stroma of the endometrium in the early secretory phase of the menstrual cycle. Northern hybridization analyses revealed that expression of thioredoxin mRNA in the endometrium of the early secretory phase was approximately 3-fold compared to the other phases of the menstrual cycle, consistent with the results of the immunohistochemical studies. These results suggest that both protein and gene expression of thioredoxin in the endometrium are menstrual cycle phase-specific and highly active in the phase of endometrial differentiation which occurs in preparation for implantation (early secretory phase of the menstrual cycle). Thioredoxin expressed in the early secretory phase of the menstrual cycle may be advantageous for blastocyst implantation.

Endometrium↗
PubMed1997

Effects of a GnRH analogue on human smooth muscle cells cultured from normal myometrial and from uterine leiomyomal tissues.

Leiomyomas are tumours of uterine smooth muscle tissue that are oestrogen and progesterone dependent. When explants of these tumours were grown in culture, the proliferating tissue formed characteristic ball-like aggregates (BLA), rather than the usual hill and valley (HV) pattern of growth of normal myometrial tissue in culture. Immunocytochemical staining with fluorescein isothiocyanate (FITC)-labelled gonadotrophin-releasing hormone (GnRH) revealed that both myometrial and leiomyomal cells have membrane receptors for this hypothalamic releasing hormone. Furthermore, polymerase chain reactions (PCR) with primer sets that were specific for GnRH receptor mRNA, as well as GnRH mRNA, showed that transcripts for both of these nucleic acids are present in myometrial and leiomyomal tissues. The treatment of cultured explants of leiomyomal tissue with a GnRH analogue (buserelin, HOE766) diminished the formation of BLA, but this synthetic hormone had only a moderate effect on the HV topography of normal myometrial tissue. A colorimetric assay indicated that GnRHa inhibited cell proliferation in leiomyomal tissue in a dose-dependent manner. Western blotting, to detect the expression of G1 phase cell cycle-related gene products, showed that cyclin E and p33cdk2 formation in leiomyomas were inhibited by high concentrations of GnRHa. In conclusion, GnRHa might suppress leiomyomal growth by interfering with the expression of cell cycle factors.

Base Sequence↗
PubMed1997

Analysis of stem cell factor for mast cell proliferation in the human myometrium.

The proliferation and differentiation of human mast cells (MCs) occur under the influence of the mitogenic agent known as stem cell factor (SCF). This study analyses the distribution of SCF and SCF receptor in human myometrial tissue to further the understanding of the role(s) of MCs in the uterus. Immunohistochemical staining revealed that the majority of uterine MCs are located in close proximity to myometrial smooth muscle cells, and also among fibroblast-like spindle shaped cells. RNA extracts from myometrial tissues were subjected to reverse transcription. The resulting cDNA population was amplified by polymerase chain reaction (PCR) using a pair of 20-mer primers that were specific for SCF cDNA. Electrophoresis of the PCR products showed that the myometrial tissues contained transcripts for SCF. In-situ reverse transcription-PCR also revealed the expression of the transcripts for SCF in myometrial smooth muscle cells. Furthermore, enzyme-linked immunosorbent assays confirmed that the cultured myometrial cells produced SCF. Since immunohistochemical staining indicated there are SCF receptors on the surface of myometrial MCs, the results suggest that MC proliferation and differentiation in the myometrium is regulated by SCF secretion from the uterine smooth muscle cells. The mature MCs might, in turn, secrete mediators that influence tissue remodelling during the human menstrual cycle.

Base Sequence↗
PubMed1997

Nanomolar quantification and identification of various nitrosothiols by high performance liquid chromatography coupled with flow reactors of metals and Griess reagent.

Nitrosothiols (RS-NOs) appear to be critically involved in various signal transduction mechanisms. We describe here a specific and highly sensitive quantification method for RS-NOs by using high performance liquid chromatography (HPLC) combined with a flow reactor system. RS-NOs were applied to an HPLC system of C18-reverse phase or a gel filtration column and eluted with 10 mM sodium acetate buffer (pH 5.5) plus 0.5 mM diethylenetriamine pentaacetic acid with or without either 0-7% methanol or 0.15 M NaCl. The eluate from the HPLC column was mixed with a solution containing 1.75 mM HgCl2 or 1.75 mM CuSO4 for RS-NO decomposition in a reaction coil via a three-way connector. NO2- generated via the metal-induced RS-NO decomposition was then reacted with Griess reagent, which was infused through a second three-way connector, yielding a diazo-compound detected at 540 nm. In a separate experiment, a copper particle-loaded column was used for RS-NO degradation instead of the metal-ion flow reactor. In all RS-NOs tested, i.e., nitrosoglutathione (GS-NO), nitroso-L-cysteine, and nitrosoalbumin, the nitroso- group was converted to NO2- by the Hg2+-reaction system as well as copper-loaded column, and the recovery was almost 100%. The Cu2+-solution flow reaction system, however, yielded only 30% recovery of RS-NOs as NO2-. Also, the RS-NOs could be identified at nanomolar concentrations: detection limit, 3.0 nM in a 150-microl aliquot. These RS-NOs showed well-resolved elution profiles even in the presence of NO2- and NO3-. More importantly, biological generation of GS-NO was quantitatively demonstrated with RAW264 cells in culture incorporating free GSH in the medium. In conclusion, our novel RS-NO assay will be useful to examine the formation and functions of RS-NOs in biological systems.

Animals↗
PubMed1997

Result of long-term administration of L-threo-3,4-dihydroxyphenylserine in patients with pure akinesia as an early symptom of progressive supranuclear palsy.

Results of long-term administration of L-threo-3,4-dihydroxyphenylserine (L-DOPS), a synthetic precursor of noradrenaline, in a patient with freezing gait and pure akinesia are reported. Effects were temporal and disappeared during a 16-month treatment period. It was recognized that pure akinesia is an early symptom of progressive supranuclear palsy (PSP). Previously, we reported results of short-term (4 weeks) administration of L-DOPS in this patient. We present the further clinical course of the patient, along with results of long-term (16 months) administration of L-DOPS.

Antiparkinson Agents↗
PubMed1997

Minimal deviation adenocarcinoma of the uterine cervix has abnormal expression of sex steroid receptors, CA125, and gastric mucin.

To provide clues to the histological differentiation between minimal deviation adenocarcinoma (MDA) of the uterine cervix and normal cervical glands, we analyze the histochemical expression of ovarian steroid receptors [estrogen receptor (ER) and progesterone receptor (PR)], mucosubstances such as gastric mucin, CA125, and carcinoembryonic antigen (CEA) in normal cervical glands (10 cases) and MDA (seven cases). Mucin histochemistry showed that gastric mucin was focally demonstrated in all the cases of MDA but in none of the normal cervical glands. ER and PR were not expressed in MDA, whereas both receptors were invariably expressed in normal cervices. Expression of CA125 was significantly decreased in MDA, but was diffusely positive in normal endocervical glands. CEA was focally positive in all cases of MDA, but it was consistently negative in normal cervical glands. These results suggest that MDA lacks expression of the characteristic müllerian-type substances such as ER, PR, and CA125, and that a proportion of its cells contain gastric epithelial substances, comprising gastric mucin and CEA. In conclusion, loss of the expression of ER and PR, decreased expression of CA125, and staining for gastric mucin and CEA could be used for histologic discrimination of MDA from benign cervical glands.

Adenocarcinoma↗
PubMed1997

Immunohistochemical detection of cyclin A with reference to p53 expression in endometrial endometrioid carcinomas.

Cyclins are essential proteins in cell cycle control, and their deranged expression has been reported to be associated with malignant transformation. Involvement of cyclins in the development of endometrioid carcinomas of the endometrium was studied immunohistochemically using antibodies against both cyclin A and tumor suppressor gene product p53, and their expression was compared with that of Ki-67 antigen. Sixty-two cases of endometrial endometrioid carcinoma and 20 cases of normal endometrium (10 proliferative and 10 secretory phase) were examined. Of the 62 endometrioid carcinomas, atrophic endometrium and hyperplasia were found adjacent to the cancers in 30 and 19 cases respectively. Cyclin A was expressed in < 1% of the glandular cells of normal endometrium in the proliferative phase and in hyperplasia, but was negligible in normal secretory phase and atrophic endometrium. p53 was almost always negative in normal endometrium and hyperplasia. Of the 62 endometrioid carcinomas, 12 tumors (19.4%) overexpressed cyclin A and 21 tumors (33.8%) overexpressed p53 (positive cells > 1%). Cyclin A and p53 were more frequently expressed in poorly differentiated tumors than in well differentiated tumors (cyclin A, p = 0.002; p53, p = 0.016). In addition, cyclin A-positive cells were topographically related to those cells positive for p53 as well as Ki-67. In conclusion, the abnormal expression of cyclin A and p53 is associated with high-grade endometrial endometrioid carcinomas.

Adult↗
PubMed1997

Expressions of cell cycle regulators in human colorectal cancer cell lines.

To study the altered mechanisms of cell cycle regulation in colorectal cancer, the expressions of cyclins, cyclin-dependent kinases (CDKs), CDK inhibitors, p53 and retinoblastoma (Rb) protein were analyzed by western blotting in a series of human colorectal cancer cell lines. The colorectal cancer cell lines exhibited various expression patterns of cell cycle regulators, which may reflect differences in the biological characteristics of cancer cells and in the genetic backgrounds of carcinogenesis. A correlation was found between p53 gene alteration and p21 expression, suggesting that p53 gene mutation usually suppresses p21 expression, though p21 expression could be induced via both a p53-dependent and a p53-independent pathway in colorectal cancer. None of the cell lines studied expressed p16 protein, suggesting that inactivation of p16 may be a common alteration in colorectal cancer. Moreover, all the D-type cyclins, especially D2 and D3, were expressed at a high level in most of the cell lines. Loss of p16 expression and increased expression of D-type cyclins promote CDK-mediated Rb phosphorylation. All of the colorectal cancer cell lines studied herein expressed Rb protein, but the growth-suppressive properties of Rb may be inactivated by the loss of p16 expression and increased expressions of D-type cyclins. In view of the pivotal role of Rb in cell cycle regulation, loss of p16 expression and overexpression of D-type cyclins may be critical alterations in colorectal cancer.

Cell Cycle↗
PubMed1997

Identification of T-cell epitope sequences on an important mite antigen.

BACKGROUND: T-cell epitopes on Der 1 and Der 2 groups, the major mite allergens, have been intensively analysed, while those on the other important allergens remain to be elucidated. We have cloned four cDNAs coding for important mite allergens on the basis of frequency and capacity of IgE binding. Stimulatory action of glutathione S-transferase-fused Mag1 on lymphocytes from mite-allergic patients was relatively high among them. OBJECTIVE: To identify T-cell epitopes on Mag1, we studied the stimulating activity of truncated Mag1 proteins and synthetic peptides on proliferative response of lymphocytes from mite antigen-immunized mice and mite-sensitive patients. METHODS: Truncated Mag1 proteins were expressed as a fusion protein with beta-galactosidase in Escherichia coli pop2136 carrying a variety of deleted Mag1 inserts. Murine T-cell epitope regions were estimated by the truncated antigen-induced lymphocyte proliferation assay. Overlapping peptides covering the whole sequence of the presumed T-cell epitope regions were synthesized to identify the epitope core sequences using murine and human Mag1-specific T-cell lines. RESULTS: Amino acid range 56-70 on Mag1 molecule showed remarkable stimulatory action on murine T cells, while amino acid ranges 51-65 and 86-100 had potent stimulatory activity on human T cells. CONCLUSIONS: These results suggest that Mag1 is a valuable antigen suitable for studies on T-cell responses and T-cell epitopes in mice and humans.

Animals↗
PubMed1997

Induction of nitric oxide synthesis and xanthine oxidase and their roles in the antimicrobial mechanism against Salmonella typhimurium infection in mice.

The role of superoxide anion (O2-) and nitric oxide (NO) in the host defense mechanism against Salmonella typhimurium (LT-2) was examined by focusing on xanthine oxidase (XO) as an O2(-)-generating system and on inducible NO synthase (iNOS). When ICR mice were infected with a 0.1 50% lethal dose (2 x 10(5) CFU) of S. typhimurium, bacterial growth in the liver reached a peak value 3 days after infection (10(4.32) CFU/g of liver) and decreased thereafter. XO activity in the liver became maximum at 7 days after infection; the value was 34.6 +/- 1.4 mU/g of liver at 7 days (compared with 11.0 +/- 1.3 mU/g of liver before infection). The time profile of NO production in the liver as determined by electron spin resonance spectroscopy was consistent with that of XO activity. Histological examination of infected liver showed the formation of multiple microabscesses with granulomatous lesions consisting of polymorphonuclear cells and mononuclear cells, and iNOS-expressing cells were localized in the confined areas of the microabscesses. When XO inhibitors such as allopurinol and 4-amino-6-hydroxypyrazolo[3,4-d]pyrimidine (AHPP) were administered to the infected mice, the mortality of the mice was significantly increased (10 of 21 and 11 of 20 for the allopurinol- and AHPP-treated groups, respectively, versus 2 of 20 for control mice), and bacterial growth was significantly enhanced. A similar exacerbation of the infection was obtained with N(omega)-monomethyl-L-arginine (L-NMMA) treatment of the mice. Of considerable importance is that granuloma formation in the liver was poorly developed by treatment with either XO inhibitors or L-NMMA. These results suggest that XO and NO play an important role in the antimicrobial mechanism against S. typhimurium in mice.

Allopurinol↗
PubMed1997

Factors inducing codistribution of marginal actin fibers and fibronectin in rat aortic endothelial cells.

Rat endothelial cells have a unique arrangement of actin fibers running with subendothelial fibronectin along the cell margins. The present study was conducted to identify the factors that are associated with codistribution of these actin fibers and fibronectin in fetal rat aortic endothelial cells, mainly using rheological techniques. Fluorescence histochemistry revealed that the codistribution pattern was established between gestational days 14 and 15. The endothelial cells changed from polygonal to spindle shaped during this gestational period. Although the aortic length remained almost unchanged during this period of gestation, both the diameter and expansion ratio of the aorta increased, by 9 and 10%, respectively. On the other hand, the wall shear rate increased rapidly during gestational days 13-16. These results indicate that the codistribution of actin fibers and subendothelial fibronectin along the margins of endothelial cells in fetal rat aorta occurs in association with a rise in stretch and shear stress and that the endothelial cells may require this change to maintain structural integrity.

Actin Cytoskeleton↗
PubMed1997

A novel prespore-cell-inducing factor in Dictyostelium discoideum induces cell division of prespore cells.

In Dictyostelium discoideum strain V12M2, at a very low cell density (approximately 10(2) cells/cm2), most amoebae differentiate into prespore cells in a salt solution containing cAMP if an adequately diluted conditioned medium (CM) is provided (Oohata, A. A. (1995) Differentiation 59, 283-288). This finding suggests the presence of factor(s) released into the medium that are involved in inducing prespore cell differentiation. In the present study, we report the presence of two types of factors that function synergistically in prespore cell induction; one is a heat-stable and dialysable factor(s) and the other is a heat-labile and non-dialysable factor termed psi (psi) factor (prespore-inducing factor). We purified and characterized the psi factor. Its relative molecular mass was determined to be 106x10(3) Mr by SDS-PAGE and 180x10(3) Mr by gel filtration HPLC, respectively. These results indicate that psi factor exists as a dimer under native conditions. In addition to inducing prespore cell differentiation, psi factor induced cell division of prespore cells in submerged culture. Our results suggest that psi factor plays important roles not only in prespore cell differentiation but also in the progress of the cell cycle in the prespore pathway in normal development.

Animals↗
PubMed1997

Effect of cilnidipine, a novel dihydropyridine Ca++-channel antagonist, on N-type Ca++ channel in rat dorsal root ganglion neurons.

We investigated the effects of cilnidipine, a dihydropyridine derivative, on neuronal Ca++ channels in rat dorsal root ganglion neurons. Voltage-dependent Ca++-channel currents were recorded, using 5 mM Ba++ as the charge carrier, by means of the whole-cell patch-clamp technique. The Ba++ current was subdivided pharmacologically into calciseptine-sensitive (L-type), omega-conotoxin GVIA- (omegaCgTx) sensitive (N-type), omega-agatoxin IVA- (omegaAgTx) sensitive (P/Q-type) and toxin-resistant currents. Cilnidipine inhibited the L-type current with an IC50 of 100 nM in neurons pretreated with omegaCgTx plus omegaAgTx. In neurons pretreated with Cal plus omegaAgTx, cilnidipine induced a potent inhibition of the N-type current, but was unable to block the residual Ba++ current. The IC50 for cilnidipine in respect of the N-type current was 200 nM. Cilnidipine (300-500 nM) modified neither the voltage-dependent inactivation curve nor the decay of the N-type current. Furthermore, elevation of the holding potential did not enhance the inhibitory action of cilnidipine (300 nM) on the N-type current. No effect was induced by 100 nM cilnidipine on the P/Q-type current. However, nicardipine (1 microM) barely inhibited the N-type current at a concentration that almost completely blocked the L-type current. In conclusion, cilnidipine has potent inhibitory actions on N-type as well as L-type voltage-dependent Ca++-channel in rat dorsal root ganglion neurons. The former action may bestow an additional clinical advantage for the treatment of hypertension, such as suppression of reflex tachycardia.

Animals↗
PubMed1997

[Usefulness of directional coronary atherectomy as a bail-out device for acute closure after coronary angioplasty].

The usefulness of directional coronary atherectomy (DCA) as a bail-out device for acute closure (reclosure) after percutaneous transluminal coronary angioplasty (PTCA) was evaluated. PTCA was performed in 1,023 patients (182 with acute myocardial infarction) between January 1993 and January 1994 in our hospital. Thirty-one patients (11 with acute myocardial infarction) suffered acute closure (reclosure) after PTCA. In six patients (five with acute myocardial infarction), DCA was performed as a rescue treatment for acute closure (reclosure). In three of these patients, angioscopy was performed before DCA, which demonstrated intimal tear and some thrombi although coronary angiography showed no evidence of thrombus. Bail-out DCA was successful in all six patients without complications. DCA is useful as a bail-out device for acute closure (reclosure) after PTCA when the thrombus is not massive.

Angioplasty, Balloon, Coronary↗
PubMed1997

Termination of early pregnancy in the rat by a single dose of human menopausal gonadotropin.

Human menopausal gonadotropin (hMG) is commonly used to induce ovarian follicular development and ovulation in infertile women. This report is a preliminary analysis of the ability of hMG to cause folliculogenesis and ovulation in pregnant laboratory animals. Wistar rats were injected subcutaneously with 0.5 mg of hMG on selected days of pregnancy. In addition, 2 days after receiving hMG, one group of animals was injected with 50 IU of human chorionic gonadotropin (hCG) as a substitute for an ovulation-inducing dose of luteinizing hormone. A single dose of hMG caused follicular development and ovulation in the pregnant animals. Furthermore, the results show that such hormone treatment usually terminated the gravid state of the animals. The frequency of pregnancy termination was greater (1) When hMG was administered during the first quarter of the 21-day gestation period; (2) When higher doses of hMG were used; and (3) When the hMG injection was followed 2 days later by hCG. In conclusion, hMG can terminate early pregnancy in a laboratory animal like the rat, and this observation raises the possibility that it may also act as an abortifacient agent in humans. Therefore, a more extensive analysis of the effects of hMG on pregnancy is warranted.

Abortifacient Agents↗
PubMed1997

Advances in the understanding of diabetic vascular disease.

In summary, the articles in this Review in Depth cover some of the most important aspects in the diabetic vascular disease. The topics included microvascular disease, macrovascular disease, coronary artery disease, diminished fibrinolysis, percutaneous transluminal coronary recanalization and PTCA. The most common manifestations of diabetic vasculopathy are emphasized. Despite an enormous database, the fundamental mechanisms responsible for the diabetic vascular disease remain poorly understood and continue to be the subject of fascinating inquiry.

Angioplasty, Balloon, Coronary↗
PubMed1997

Mechanism of decreased albuminuria caused by angiotensin converting enzyme inhibitor in early diabetic nephropathy.

The mechanism of decreased albuminuria caused by an inhibitor of angiotensin converting enzyme (ACE) was investigated in patients with early diabetic nephropathy. The subjects were 10 patients with non-insulin-dependent diabetes mellitus without azotemia but with albuminuria (less than 650 mg/day). First, a two-week study was done: one week with a diet with ordinary sodium levels and one week with a sodium-restricted diet, in random order. The systemic blood pressure and urinary excretion of sodium and albumin were measured daily. Intrarenal hemodynamics, in terms of the resistance of afferent and efferent arterioles (RA and RE) and glomerular capillary pressure (PGC), were calculated from renal clearance, the plasma total protein concentration, and the pressure-natriuresis relationship. Results obtained before and two weeks after starting the ACE inhibitor cilazapril (2 mg/day) were compared. Urinary excretion of albumin was decreased by cilazapril in 8 of the 10 patients. Cilazapril decreased the RE [6830 (3680, 14,750) to 4660 (1750, 10,790) dynes.sec.cm-5, P < 0.05, mean (minimum, maximum)] and PGC (53 +/- 5 to 43 +/- 9 mm Hg, P < 0.02, mean +/- SD) in these 8 patients, but not in the two other patients. The RA was not significantly changed in any patient. The percent change caused by cilazapril in the urinary excretion of albumin was significantly correlated with the change in PGC (N = 10, r = 0.875, P < 0.01), but not with changes in the systemic blood pressure. In conclusion, the mechanism by which an ACE inhibitor caused a short-term decrease in albuminuria in early diabetic nephropathy involved a glomerular hemodynamic change, namely, a decrease in PGC.

Aged↗