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Biomedical subjects

M Fujimoto

Publications and source records attributed to M Fujimoto.

At least 19 recordsLinked to original sources

Non-peptide bombesin receptor antagonists, kuwanon G and H, isolated from mulberry.

Kuwanon G and H, isolated from the methanol extract of Morus bombycis, inhibited specific binding of [125I]gastrin-releasing peptide (GRP) to GRP-preferring receptors in murine Swiss 3T3 fibroblasts with Ki values of 470 and 290 nM, respectively. Kuwanon H was one order of magnitude less potent for inhibiting [125I]bombesin binding to neuromedin B (NMB)-preferring receptors in rat esophagus membranes. This compound antagonized bombesin-induced increases in the cytosolic free calcium concentration and GRP-induced DNA synthesis in Swiss 3T3 cells. Thus, kuwanon H, and possibly kuwanon G also, are specific antagonists for the GRP-preferring receptor and can be useful for studying the physiological and pathological role of GRP.

3T3 Cells

Influence of spontaneous portosystemic collateral pathways on portal hemodynamics in living-related liver transplantation in children. Doppler ultrasonographic study.

We investigated the influence of spontaneous portosystemic collateral pathways on the portal hemodynamics and examined the necessity for ligating these vessels in pediatric liver transplantation from living donors. We assessed portal blood flow before, during, and after surgery in 82 pediatric recipients (mean age, 4.2 years), using Doppler ultrasonography. When blood flow in the reconstructed portal vein was decreased (< 10 ml/min/kg body weight) and portosystemic collaterals persisted during surgery, those vessels were ligated and Doppler flowmetry was examined again. Spontaneous portosystemic collaterals were detected at one or more sites in 67 patients before transplantation. These collaterals had been ligated in 17 patients before intraoperative flowmetry. Among the remaining 50 patients, initial Doppler studies revealed a decrease in portal blood flow in 22 patients. Nine patients had hepatofugal splenic venous flow and 6 had no significant flow signals from the intrahepatic portal vein. Ligation of collaterals resulted in a remarkable increase in portal blood flow in 20 patients, all of whom are alive. The remaining 2 patients died of graft failure due in part to portal hypoperfusion. On the other hand, the collaterals were not ligated in 24 patients because adequate portal blood flow was confirmed by intraoperative flowmetry. Postoperatively, flow signals from the unligated collateral vessels gradually diminished, but they still persisted in 3 patients at 12 months after transplantation. Hepatofugal blood flow through the portosystemic collateral pathways may persist after implantation of a normal graft. If the patent collaterals significantly reduce the effective portal blood flow, these vessels should be ligated in order to avoid graft failure.

Adolescent

Novel angiotensin II receptor antagonists. Design, synthesis, and in vitro evaluation of dibenzo[a,d]cycloheptene and dibenzo[b,f]oxepin derivatives. Searching for bioisosteres of biphenylyltetrazole using a three-dimensional search technique.

Three-dimensional substructure searching (3D search), using the program MACCS-3D, was utilized for designing novel angiotensin II receptor antagonists which contain a bioisostere of the biphenylyltetrazole moiety of DuP 753. A 3D query was prepared from an overlay model of substructures of several potent AII antagonists. The search system retrieved 139 compounds from the database MDDR-3D, which consisted of 29,400 medicinal patent compounds. A tricyclic compound was selected from the retrieved compounds and then evolved by considering steric fitness to the overlay model and synthetic feasibility. Finally, various novel AII antagonists having dibenzo[a,d]cycloheptene or dibenzo[b,f]oxepin were designed and synthesized. The receptor binding activity (Ki) for several members of this series was in the 10(-10) M range, demonstrating the ability of 3D search technique to explore new lead structures.

Angiotensin II

Kinetic studies on the interaction of nonlabeled antagonists with the angiotensin II receptor.

Angiotensin AT1 receptor antagonists are divided into two types, surmountable and insurmountable, based on the way they inhibit angiotensin II-induced vasoconstriction. To elucidate what causes the difference, we studied how antagonists associate with and dissociate from AT1 receptor sites in rat liver membranes. Three antagonists, 6-propyl-7-oxo-4[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-4,7- dihydropyrazolo[1,5-a]pyrimidine-3-carboxylic acid (SRL1080227), 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H- benzimidazole-7-carboxylic acid (CV-11974) and 2-butyl-3-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-3H-imidazo- [4,5-b]pyridine (FK739), showed competitive antagonism when they were added simultaneously with [125I]angiotensin II, but CV11974 and SRL1080227 showed apparently noncompetitive antagonism when membranes were preincubated with each antagonist. The longer the preincubation time with CV11974 or SRL1080227 was, the more effectively the antagonist inhibited [125I]angiotensin II binding, while the inhibition by FK739 did not change with the preincubation time. To estimate their dissociation rate from the receptor binding site, we studied [125I]angiotensin II binding to membranes which had been preincubated with each antagonist and washed twice. Membranes pretreated with FK739 completely recovered the ability to bind [125I]angiotensin II with a period of 60 min, while membranes preincubated with CV11974 did not read this level of recovery. [125I]angiotensin II binding to membranes preincubated with SRL1080227 increased gradually, but did not reach the control level during the experiment. The kinetic properties of SRL1080227, CV11974 and FK739 were consistent with their characteristic modes in inhibiting angiotensin II-induced contraction of isolated rabbit aorta and decreasing blood pressure of spontaneously hypertensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin Receptor Antagonists

Induction of IgA1 and IgA2 production in immature human fetal B cells and pre-B cells by vasoactive intestinal peptide.

We studied the effects of vasoactive intestinal peptide (VIP) on IgA1 and IgA2 production in human fetal B cells and pre-B cells derived from bone marrow. VIP induced IgA1, IgA2, and IgM production in sIgM+, CD19+ fetal B cells stimulated with anti-CD40 monoclonal antibody (MoAb) without inducing the production of IgG1, IgG2, IgG3, IgG4, or IgE. The anti-CD40 MoAb plus VIP also induced IgA1, IgA2, and IgM production in sIgM-, CD19+ pre-B cells, which was enhanced by the addition of interleukin-7 (IL-7). This induction by VIP was specific, as the anti-CD40 MoAb plus other neuropeptides [ie, somatostatin (SOM) or substance P (SP)] had no effect, and moreover, the induction was specifically blocked by a VIP antagonist. Furthermore, the anti-CD40 MoAb plus various cytokines, including IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IL-10, transforming growth factor beta (TGF-beta), low-molecular-weight B-cell growth factor (BCGF), and interferon-gamma (IFN-gamma), did not induce IgA1 and IgA2 production in fetal B cells or pre-B cells. These findings indicate that, in the presence of costimulators, VIP may induce IgA1 and IgA2 production by isotype switching.

Antibodies, Monoclonal

Interleukin 8 (IL-8) inhibits the interleukin 4 (IL-4)-induced but not the spontaneous growth of human B cells via mechanisms that may involve protein kinase C.

IL-8 inhibited the IL-4-induced but not the spontaneous growth of both a human B cell line, CBL, and in vivo activated B cells. This inhibition was specific to IL-8, since anti-IL-8 mAb, but not control IgG1, blocked inhibition. Phorbol 12, 13 dibutyrate did not affect the IL-4-induced B cell growth; however, it reversed the IL-8-mediated inhibition, and this reversal was blocked by H7 (a protein kinase C inhibitor), but not by H8 (a protein kinase A inhibitor). These results indicate that IL-8 inhibits IL-4-induced B cell growth via specific mechanisms that may involve protein kinase C.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine

Autoantibodies to pyruvate dehydrogenase complex in patients with systemic sclerosis. Possible role of anti-E1 alpha antibody as a serologic indicator for development of primary biliary cirrhosis.

OBJECTIVE: To determine the prevalence and clinical significance of anti-pyruvate dehydrogenase complex (anti-PDC) antibodies in systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (n = 81) or diffuse cutaneous SSc (n = 63) were examined for anti-PDC antibodies by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. RESULTS: IgG- and/or IgM-isotype anti-PDC antibodies were demonstrated by ELISA in 26 of 144 patients with SSc (18%). By immunoblotting, 19 patients had IgG anti-PDC antibodies. Among these patients with IgG anti-PDC antibodies, antibody to the E1 alpha subunit was significantly associated with the presence of laboratory abnormalities typical of primary biliary cirrhosis (PBC). CONCLUSION: Antibody to the E1 alpha subunit of PDC may be a serologic indicator for the development of PBC in patients with SSc.

Adult

Involvement of interleukin (IL)-13, but not IL-4, in spontaneous IgE and IgG4 production in nephrotic syndrome.

Nephrotic syndrome (NS) is a renal disease characterized by proteinuria and hypoalbuminemia. In NS patients without any allergic disease, serum IgE and IgG4 levels were selectively increased, and peripheral blood mononuclear cells (MNC) spontaneously produced IgE and IgG4. T cells produced interleukin (IL)-13 spontaneously, and B cells constitutively expressed IL-13 receptors (IL-13R). In addition, T cells stimulated surface IgE-negative (sIgE-) and sIgG4- B cells to produce IgE and IgG4, respectively, and IgE and IgG4 production was specifically blocked by anti-IL-13 antibody (Ab). MNC from atopic dermatitis (AD) patients also produced IgE and IgG4 spontaneously. However, in AD patients, T cells spontaneously produced IL-4, but not IL-13, and B cells constitutively expressed IL-4R, but not IL-13R. T cells stimulated sIgE- and sIgG4- B cells to produce IgE and IgG4, respectively, and the production was specifically blocked by anti-IL-4 Ab. On the other hand, sIgE+ and sIgG4+ B cells from both NS and AD patients spontaneously produced IgE and IgG4, respectively, and this production was not affected by T cells, anti-IL-4 Ab, or anti-IL-13 Ab. These results indicate that IL-13 is involved in the enhanced production of IgE and IgG4 in NS, while IL-4 is involved in these responses in AD.

Adolescent

Microheterogeneity of mouse antidextran monoclonal antibodies.

Mouse antidextran monoclonal antibodies showed microheterogeneity which was analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Not only the heavy (H) chains but also the light (L) chains were heterogeneous in terms of isoelectric point (pI). The higher the pI, the more prominent the H chain spots. To demonstrate the cause of the microheterogeneity an IgG1 monoclonal antibody (mAb 35.8.2H) was examined especially for involvement of the sugar moiety in the microheterogeneity. The glycosylated region was determined in the Fc portion from serine 239 to methionine 309 by a glycan detection method using mild periodate oxidation, which confirms that the sugar chain is attached to the conserved glycosylation site of asparagine 297. However, charge heterogeneity of the H chain was not entirely attributed to the Fc because the papain digest of the antibody was separated into two Fc spots, a few Fd spots and two L chain spots by 2-D PAGE. This indicates that factors other than the sugar moiety are responsible for charge heterogeneity of IgG monoclonal antibody. On the other hand, the H chain isoforms of lower pI were shown to be more susceptible to V8 protease by peptide mapping. This result strongly suggests the occurrence of deamidation at glutamine or asparagine residues.

Amino Acid Sequence

Evaluation of protective effects of prostaglandin E1 on ischemic liver damage with in vivo 31P-MR spectroscopy.

The cytoprotective effect of prostaglandins (PG) was evaluated by in vivo 31P MR spectroscopy. Twenty rabbits were divided into two groups; the control group given physiological saline, and the PG group given prostaglandin E1 (0.5 microgram/kg/min). Each solution was infused for 8 min, after which complete hepatic ischemia was induced for 20 min, followed by reperfusion for 40 min. During ischemia, beta-ATP decreased to 23.6% and 42.3%, phosphomonoester increased to 260% and 200% of their initial values in the control and the PG groups, respectively. Inorganic phosphate also increased. After reperfusion, beta-ATP recovered to 65.2% and 96.5%, phosphomonoester to 130% and 110%, inorganic phosphate to 140% and 120% in the control and PG groups, respectively. The changes during ischemia were significantly smaller and the recoveries during reperfusion were more complete in the PG group. These results may confirm the cytoprotective effect of prostaglandins by in vivo 31P-MR spectroscopy.

Adenosine Triphosphate

Recovery of graft circulation following percutaneous transluminal angioplasty for stenotic venous complications in pediatric liver transplantation: assessment with Doppler ultrasound.

Percutaneous transluminal angioplasty was performed for venous stenosis after living related liver transplantation in three children. Two of them had hepatic vein stenosis and one had stenosis of both the hepatic and portal veins. Progressive development of ascites and deterioration of liver function were found in all cases. Serial Doppler ultrasound studies showed that the flow velocity in the hepatic vein gradually decreased with a flattened velocity waveform, followed by a decrease in portal blood flow. After a successful hepatic vein angioplasty, the velocity in the hepatic and portal veins increased and the Doppler waveform in the hepatic vein became pulsatile in two cases. In the remaining case, a remarkable recovery of both graft perfusion and clinical findings was achieved via combined hepatic vein and portal vein angioplasty. We conclude that balloon angioplasty is an effective alternative to surgery for post-transplant vascular stenosis and that Doppler ultrasound is useful in monitoring graft circulation.

Angioplasty, Balloon

Autoantibodies to the heat-shock protein hsp73 in localized scleroderma.

We determined the presence of antibodies to the heat-shock protein hsp73 (anti-hsp73) in 57 serum samples from patients with localized scleroderma using an enzyme-linked immunosorbent assay (ELISA). In addition, 30 samples from healthy individuals, 30 from patients with systemic lupus erythematosus (SLE) and 32 from patients with systemic sclerosis were assessed. IgG and/or IgM anti-hsp73 antibodies were detected in 33% (19/57) of the patients with localized scleroderma. Among the three subtypes of localized scleroderma, generalized morphoea showed the highest incidence of anti-hsp73 antibodies (40%, 6/15). IgG and/or IgM anti-hsp73 antibodies were also detected in 9/30 samples (30%) from patients with SLE and in 13/32 samples (41%) from patients with systemic sclerosis, while the samples from the healthy controls were all negative for anti-hsp73. By immunoblotting, specific binding of antibodies to hsp73 was confirmed with representative serum samples that were positive for anti-hsp73 in the ELISA. Our findings indicate that the presence of anti-hsp73 is an additional immunological abnormality in localized scleroderma.

Adolescent

Demonstration of interleukin-2, interleukin-4 and interleukin-6 in sera from patients with localized scleroderma.

Localized scleroderma has been reported to be accompanied by immunological abnormalities related to B cells, but little is known about T-cell activation in this disease. In this study, serum levels of interleukin-2 (IL-2), interleukin-4 (IL-4) and interleukin-6 (IL-6), which are known to be released by activated T cells, were determined using a sensitive enzyme-linked immunosorbent assay in 48 patients with localized scleroderma and 20 with systemic sclerosis, and in 20 healthy control subjects. IL-2, IL-4 and IL-6 were detected in serum from patients with localized scleroderma but not in that from healthy controls. The presence of antihistone antibodies correlated significantly with elevated IL-4 and IL-6 levels. Decreased serum levels of IL-2, IL-4 and IL-6 paralleled improvement in cutaneous sclerosis. Frequent detection of these lymphokines in serum from patients with localized scleroderma reflects T-cell activation in this disorder.

Autoantibodies

Kissing aneurysms of distal anterior cerebral arteries demonstrated by magnetic resonance angiography.

BACKGROUND Multiple aneurysms, associated with distal anterior cerebral artery (ACA) aneurysm, are not rare; therefore, it is important to examine multiplicity of the aneurysms preoperatively. CASE REPORT A case of ruptured distal ACA aneurysm, associated with another one in a mirror position, is reported. A 43-year-old woman suffered subarachnoid hemorrhage. Conventional angiography demonstrated a saccular aneurysm on the bifurcation of the right or left distal ACA; however, magnetic resonance angiography (MRA) revealed two mirror-image aneurysms on both bifurcations. CONCLUSION MRA was useful for preoperative diagnosis of kissing aneurysms on distal ACAs.

Adult

Vascular complications in living related liver transplantation detected with intraoperative and postoperative Doppler US.

BACKGROUND/AIMS: The purpose of this study was to clarify changes in the graft hemodynamics induced by vascular complications in living related liver transplantation. METHODS: This study included 46 pediatric recipients who underwent partial liver transplantation from living related donors. The blood flow was evaluated in the portal system, the hepatic artery and the hepatic vein with serial intra- and post-operative Doppler ultrasound (US). RESULTS: In 12 patients, intraoperative Doppler US showed a decrease in portal venous inflow (< 9 ml.min-1.kg-1) toward the liver graft and could act as a guide for ligation of collaterals in seven patients, portal re-construction in two, thrombectomy in one and relief of hepatic venous outflow obstruction in two for increasing the portal venous inflow. In five patients, intraoperative Doppler US showed poor arterial inflow, i.e. dampened arterial waveforms which involved both low pulsatility index (< 0.90) and low peak-systolic velocity (< 31 cm/s). In three of them, the waveform was more pulsatile after re-anastomosis or relief from stretching of the hepatic artery. The remaining two patients developed hepatic artery thrombosis. Most of the hepatic venous outflow obstruction (four of five patients) had flat waveforms, low flow velocity (< 10 cm/s) of the hepatic vein, and poor portal inflow (flow velocity < 14 cm/s). Postoperative Doppler US showed hepatic venous outflow obstruction in three patients, hepatic artery thrombosis in three (twice in one patient), portal vein stenosis in two and portal vein thrombosis in one. These complications were successfully managed with surgical procedures in three patients, transhepatic angioplasty in three and conservative treatments in four. Six patients died of non-vascular complications. CONCLUSIONS: Serial intra- and post-operative Doppler US was a useful technique for making an early diagnosis of abnormal hemodynamics of the graft circulation. Furthermore, intraoperative Doppler US could assess reconstructed vessels objectively and would reduce the incidence of vascular complications following transplantation.

Adolescent

Serum tissue inhibitor of metalloproteinases in patients with systemic sclerosis.

BACKGROUND: One of the suggested contributory factors to the development of dermal fibrosis is a decrease in collagenase activity, which may be related to levels of serum tissue inhibitors of metalloproteinase-1 (TIMP-1). OBJECTIVE: The aim of this study was to determine the clinical significance of serum TIMP-1 levels in systemic sclerosis (SSc). METHODS: We measured serum TIMP-1 concentration in 62 patients with SSc, 11 patients with systemic lupus erythematosus, 14 patients with rheumatoid arthritis, and 22 members of a normal control group. The clinical features of the patients with SSc and elevated TIMP levels were examined. RESULTS: The mean TIMP-1 level in the patients with SSc was significantly higher than that in the members of the control group or the patients with systemic lupus erythematosus or rheumatoid arthritis. In 44% of the patients with SSc the serum TIMP-1 level was elevated. The mean serum TIMP-1 level in patients with diffuse cutaneous SSc (dSSc) was significantly higher than that in those with limited cutaneous SSc. The patients with dSSc and elevated serum TIMP-1 levels showed a significantly greater incidence of lung fibrosis and anti-topoisomerase I antibody than those with normal serum TIMP-1 levels. The TIMP-1 level and diffusing capacity for carbon monoxide in the patients with SSc were negatively correlated. Increased mitogenic activity on dermal fibroblasts caused by serum from patients with dSSc was partially blocked by anti-TIMP-1 IgG. CONCLUSIONS: These findings suggest that serum TIMP-1 level is a useful indicator of disease activity in patients with SSc and that TIMP is involved in the pathogenesis of SSc.

Adolescent