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Biomedical subjects

I Maruyama

Publications and source records attributed to I Maruyama.

At least 19 recordsLinked to original sources
PubMed2001

Simultaneous measurement of anandamide and 2-arachidonoylglycerol by polymyxin B-selective adsorption and subsequent high-performance liquid chromatography analysis: increase in endogenous cannabinoids in the sera of patients with endotoxic shock.

Anandamide (ANA) and 2-arachidonoylglycerol (2-AG), two endogenous cannabinoids, can be generated by activated macrophages and platelets, respectively, in the context of endotoxic shock, and are proposed to play a crucial role in the induction of the shock-related hypotension. Taking advantage of our recently discovered function of polymyxin B (PMB) binding to ANA and 2-AG, we developed a new method for measuring ANA and 2-AG by applying PMB-immobilized beads to selectively adsorb them in biological fluids, instead of organic solvent extraction. The eluate from beads can be directly fractionated by reverse-phase high-performance liquid chromatography (HPLC), and the fractionations corresponding to authentic ANA and 2-AG are collected and derivatized with fluorogenic reagent and subsequently quantified by HPLC with fluorometric detection. The calibration graphs of ANA and 2-AG were linear over a range of 1 to 500 pmol/ml. The limits of detection for ANA and 2-AG were 20 and 50 fmol, respectively. Intraassay precision was 2.24-4.25 and 3.47-5.44%, and interassay was 4.05-6.14 and 4.92-7.28% for ANA and 2-AG, respectively. Using this method, we first determined a 4-fold and 3-fold higher level of ANA and 2-AG, respectively, in the sera of patients with endotoxic shock than in normal serum. This finding should help in elucidating the role of the endogenous cannabinoids in the hypotension of human endotoxic shock. This method is rapid, sensitive, and reliable for simultaneously quantifying ANA and 2-AG in biological fluids, and has potential for clinical usage.

Adsorption↗
PubMed2001

Phosphoinositide-3 kinase-PKB/Akt pathway activation is involved in fibroblast Rat-1 transformation by human T-cell leukemia virus type I tax.

Activated phosphoinositide 3-kinase (PI3K) and its downstream target Akt are essential for the fibroblast transformation induced by many viral products. Tax, encoded by human T-cell leukemia virus type I (HTLV-I), has been demonstrated to induce the transformation of rat fibroblast Rat-1 cell through NF-kappaB activation. By stable transfection of Rat-1 cells with expressing constructs of Tax and its mutant M47, which is defective in HTLV-I LTR transactivation, we selected their transformed clones, which have characteristics of NF-kappaB activation and colony formation beyond the cell monolayer (a malignant phenotype). However, these two characteristics in the transformed clones of Tax and M47 disappear after these cells have been treated with wortmannin, a specific inhibitor of PI3K. Further, increased activity of the PI3K/Akt is observed in the transformed clones of Tax and M47 as compared to the clones of empty vector Neo and the M148, which is defective in NF-kappaB activation and cell transformation. Increased activity of PI5K is present in the transformed clones of both Tax and M47 and in the M148 clone as compared to that in the Neo cell. It is known that the efficiency of Tax-induced cell transformation is not high; a minority of Tax-expressing clones show transformation, although the majority of Tax-expressing clones show activated NF-kappaB. A Tax-expressing, nontransformed clone after transfection with an active form of the catalytic subunit of PI3K, p110alpha, becomes transformed. Consistent with these results, a Tax highly-expressing human T-cell line MT2 exhibits both higher polyphosphoinositide turnover and higher activities of PI3K and PI5K than those of Jurkat or MT1 and HTLV-I-negative and a Tax-unexpressing cell line, respectively. These results demonstrate that the activation of the PI3K/Akt signaling pathway, excepting for the NF-kappaB, is also required for the cell transformation induced by Tax.

Androstadienes↗
PubMed2001

Expression of vascular endothelial growth factor in tuberculous meningitis.

The pathogenesis of tuberculous meningitis is still unclear. Recently, vascular endothelial growth factor (VEGF) was found to be associated with inflammatory diseases and we found the increased serum level of VEGF in pulmonary tuberculosis. We hypothesized that VEGF might be associated with the pathogenesis of tuberculous meningitis and measured serum and cerebrospinal fluid (CSF) levels of VEGF in 28 patients with tuberculous meningitis and 31 non-tuberculous infectious meningitis patients (13 bacterial meningitis patients, eight fungal meningitis patients and 10 patients with viral meningitis) before therapy. We examined the CSF VEGF levels 3 months after in 12 tuberculous meningitis patients. The serum and CSF levels of VEGF were significantly higher in tuberculous meningitis than in other meningitis. The decrease in titer of CSF VEGF paralleled the clinical improvement of tuberculous meningitis. Immunohistochemical staining of autopsied brains demonstrated the presence of VEGF in the inflammatory mononuclear cells of the dense fibroconnective tissue both in the subarachnoid space and surrounding the vasculitis lesion. We found the expression of VEGF in tuberculous meningitis and think that VEGF reflects its activity.

Adolescent↗
PubMed2001

Frameshift mutation in the collagen VI gene causes Ullrich's disease.

Patients with Ullrich's disease have generalized muscle weakness, multiple contractures of the proximal joints, and hyperextensibility of the distal joints. Recently, we found a deficiency of collagen VI protein in two patients with Ullrich's disease. In this study, we detected a homozygous 26 bp deletion in exon 14 of the collagen VI alpha 2 gene (COL6A2) in one patient. This mutation causes a frameshift and a premature termination codon, and results in a truncated collagen VI alpha 2 chain. Our data suggest that at least some cases of Ullrich's disease result from recessive mutations in COL6A2.

Adult↗
PubMed2001

Acute effects of stereotactic radiosurgery on the kinetics of glucose metabolism in metastatic brain tumors: FDG PET study.

UNLABELLED: Hyperacute changes in the expression of glycolysis-associate gene products as well as FDG uptake in tumor cells after high-dose irradiation reflect response of the cells to noxious intervention and may be a potential indicator of the outcome of treatment. To understand acute effects on the kinetics of glucose metabolism of tumors in vivo after high-dose irradiation, we analyzed dynamic FDG PET data in patients with metastatic brain tumors receiving stereotactic radiosurgery. MATERIALS AND METHODS: We studied 5 patients with metastatic brain tumors by means of dynamic FDG PET before and 4 hours after stereotactic radiosurgery. Rate constants of glucose metabolism (K1*- k3*) were determined in a total of 13 tumors by a non-linear least squares fitting method for dynamic PET and arterial blood sampling data. Rate constants after radiosurgery were compared with those before radiosurgery. Changes in the rate constants induced by the therapy were also correlated with changes in tumor size evaluated by CT and/or MRI 6 months later. RESULTS: Four hours after radiosurgery, the phosphorylation rate indicated by k3* was significantly higher (0.080 +/- 0.058) than that before radiosurgery (0.049 +/- 0.023) (p < 0.05, paired t test), but there was no significant change in the membrane transport rates indicated by K1* and k2*. Although increases in the net influx rate constant K* (= K1*k3*/(k2* + k3*)) were correlated with increases in k3*, K* after radiosurgery (0.027 +/- 0.011) was not significantly different from that before the therapy (0.024 +/- 0.012). The reduction in the tumor size was correlated with k3* after radiosurgery. CONCLUSION: Acceleration of the phosphorylation process was demonstrated in vivo in metastatic brain tumors as early as 4 hours after stereotactic radiosurgery, as shown experimentally in vitro in a previous report. The phenomenon may be a sensitive indicator of cell damage.

Aged↗
PubMed2001

A possible role for leptin in normo- or hypoparathyroid uremic bone in postmenopausal dialysis women.

Leptin has been proposed to be a key molecule involved in energy regulation. Based on the generally acknowledged concept that a heavier person has a higher bone density, leptin is thought to be potentially involved in bone metabolism. Serum leptin, various bone markers, and bone mineral density (BMD) were studied in 51 dialysis patients (26 men and 25 women). The serum concentrations of leptin in dialysis patients ranged from 0.7 to 10.4 ng/ml (mean 3.2 +/- 2.1 ng/ml) for males and from 1.4 to 44.6 ng/ml (mean 11.8 +/- 10.4 ng/ml) for females. There was a good correlation between the body mass index (BMI) and leptin concentration in both male and female patients (P < 0.05). Serum leptin levels also correlated well with the age-adjusted z-score for BMD (P < 0.02) and were inversely correlated with levels of the carboxy-terminal propeptide of type I procollagen (P < 0.05) in females patients, but not in male patients. In conclusion, these results suggest an actual contribution of serum leptin in maintaining bone density in postmenopausal female dialysis patients.

Adult↗
PubMed2001

Study of cell-material interaction by estimating NF-kappaB activation in HeLa S3 cells adhered onto hydrophilic substrates.

In order to interpret how cells recognize biomaterials, nucleic factor-kappa B (NF-kappaB) activation in the attached HeLa S3 cells on various substrates was evaluated. As substrates, materials of hydrophilic nature (cellulose, poly(acrylamide)-grafted poly(ethylene) (PAAm-g-PE), and lipids films) were used. The contemporary assay method for NF-kappaB was modified to fit our system. As a result, NF-kappaB activation varied depending on the substrates. The NF-kappaB outcome was induced significantly in the HeLa S3 cells that had adhered onto the lipid films in a short time. On the other hand, high levels of NF-kappaB induction were observed in the HeLa cells adhered to the celluose and PAAm-g-PE after a 24 h incubation period. The induction of NF-kappaB by cell-material interaction is discussed from the point of view of biocompatibility.

Cell Adhesion↗
PubMed2001

Vascular endothelial growth factor (VEGF) is one of the cytokines causative and predictive of hepatic veno-occlusive disease (VOD) in stem cell transplantation.

Hepatic veno-occlusive disease (VOD) is one of the most serious complications in patients receiving stem cell transplantation (SCT). However, the cause of VOD remained to be elucidated. Vascular endothelial growth factor (VEGF) has been reported to have various physiological effects including neovascularization and acceleration of vasopermeability. Because we postulated that VEGF could be one of the causative factors in VOD after SCT, serum VEGF levels were measured by ELISA in 50 patients receiving SCT. Six of the patients showed typical manifestations of VOD and four of them died due to VOD. The mean maximum serum VEGF level in the six patients with VOD was markedly increased compared to that in the patients without VOD (P < 0.001) and in normal controls (P < 0.001). Moreover, the mean maximum serum VEGF level in patients with VOD before conditioning chemoradiotherapy for SCT was also high compared to patients without VOD (P = 0.0012) in the same period. Similarly, serum VEGF levels were significantly higher in patients whose plasma protein C activities decreased below 40% (P < 0.001). During the clinical course of VOD after SCT, the increase of serum VEGF synchronized fairly well with the development of VOD. Since VEGF causes the expression of tissue factor on circulating monocyte/macrophages and results in hypercoagulability, our observation suggests that in the patients with VOD who showed high serum VEGF it might account for the development of VOD. Furthermore, this observation may indicate a novel therapeutic strategy for prevention of VOD.

Adolescent↗
PubMed2001

Expression of type XII collagen and hemidesmosome-associated proteins in keratoconus corneas.

PURPOSE: Keratoconus is a disease characterized by thinning of the central and paracentral cornea and scarring in advanced cases. This study was performed to examine the expression of type XII collagen, proteins associated with hemidesmosomes, and beta1 integrin in keratoconus corneas. METHODS: Corneal buttons were collected from normal subjects and patients with keratoconus and other corneal diseases. Immunofluorescence staining was performed on frozen sections for type XII collagen, bullous pemphigoid antigen (BP180), and integrin subunits alpha6, beta4, and beta1. RESULTS: To varying degrees, all proteins examined were expressed in normal human corneas. The staining intensity of type XII collagen was diminished in keratoconus corneas in the epithelial basement membrane zone and the stromal matrix. No significant variation was found in either the staining patterns or intensities for BP180, or integrins alpha6, beta4, and beta1. CONCLUSIONS: The level of type XII collagen was reduced in the epithelial basement membrane zone and stromal matrices in keratoconus corneas. These alterations may affect critical interactions of the corneal epithelium with the under-lying basement membrane, and cell-matrix interactions and matrix organization in the stroma.

Adolescent↗
PubMed2001

Upregulation of toll-like receptor 2 gene expression in macrophage response to peptidoglycan and high concentration of lipopolysaccharide is involved in NF-kappa b activation.

Toll-like receptors 2 and 4 (TLR2 and TLR4) have been found to transduce signals of peptidoglycan (PGN) and lipopolysaccharide (LPS), respectively, for NF-kappa B activation. However, little is known about the expression and regulation of the TLR2 gene in monocytes/macrophages in response to the two typical bacterial products. We show in the present study that both PGN and a high concentration of LPS increase TLR2 gene expression in macrophage-like cells, 1 alpha,25-dihydroxyvitamin D(3)-differentiated human HL60 and mouse RAW264.7 cells, and human monocytes in a dose- and time-dependent manner. Actinomycin D and pyrrolidine dithiocarbamate inhibition of gene transcription and NF-kappa B activation, respectively, blocks LPS- and PGN-elevated TLR2 mRNA in monocytic cells. The LPS-induced increase in TLR2 mRNA in monocytic cells is abolished by polymyxin B pretreatment and is observed in peripheral blood mononuclear cells from pigs subjected to endotoxic shock. Further, high concentrations of LPS and synthetic lipid A increase TLR2 mRNA expression in peritoneal macrophages from both TLR4-deficient C3H/HeJ mice and normal C3H/HeN mice, a process that constitutes induction of TLR4-independent TLR2 expression. These findings demonstrate that TLR2 gene expression is upregulated in macrophage responses to PGN and to high concentrations of LPS in vitro and in vivo and correlates with NF-kappa B activation.

Animals↗
PubMed2001

Potential value of CML-Hb in predicting the progression of bone cysts in dialysis-related amyloidosis.

BACKGROUND/AIM: Carboxymethyllysine is one of the common advanced glycation end products in vivo. In a previous report, we were the first to describe the increase of circulating carboxymethyllysine-hemoglobin (CML-Hb) levels in hemodialysis patients, particularly in patients with dialysis-related amyloidosis (DRA). The aim of this study was to investigate the predictive value of CML-Hb in the progression of DRA using computed tomography images of 2-year or 3-year follow-up periods of patients with amyloid bone cysts at the hip joint. METHODS: Circulating CML-Hb levels were measured as previously reported, and computed tomography scanning was conducted from 1996 to 1998 or 1999 in 57 hemodialysis patients whose original renal disease had been confirmed to be nondiabetic. Patients who showed a new growth of cysts or a growth rate of 30% or more were classified as progressive cases, while the other patients were classified as nonprogressive cases. RESULTS: (1) The circulating CML-Hb levels showed a strong correlation with the DRA score by multiple regression analysis, and (2) patients with progression of amyloid cysts showed a significantly higher circulating CML-Hb level than patients without progression. CONCLUSION: Based upon these results, we conclude that measurement of circulating CML-Hb levels has a potential value in both judgment of the clinical state and prediction of progression of DRA in hemodialysis patients.

Amyloidosis↗
PubMed2001

Uptake and accumulation of exogenous docosahexaenoic acid by Chlorella.

Tuna oil or its hydrolysate was added to a culture of Chlorella for its nutritional fortification as a feed for rotifer. Exogenous docosahexaenoic acid (DHA) in its free form was taken up by the cells of Chlorella vulgaris strain K-22 and by other strains, but tuna oil was not taken up by the cells. Accumulated DHA was found by electron microscopy in the cells in oil droplets. All strains of Chlorella used in these experiments took up exogenous DHA into the cells. It seems that the structure of the cell wall did not affect the uptake of DHA into the Chlorella cells.

Animals↗
PubMed2001

Elevation of N-(carboxymethyl)valine residue in hemoglobin of diabetic patients. Its role in the development of diabetic nephropathy.

OBJECTIVE: Advanced glycation end products (AGEs) are a risk factor for diabetic complications. We have developed an assay method for N-(carboxymethyl)valine (CMV) of the hemoglobin (CMV-Hb), which is an AGE generated from HbA1c. Herein we describe the clinical utility of CMV-Hb measurement for the diagnosis of diabetic nephropathy RESEARCH DESIGN AND METHODS: BALB/c mice were immunized with carboxy-methylated Hb and monoclonal antibody raised against CMV-Hb. This antibody was characterized by a surface plasmon resonance. We developed a latex immunoassay using the antibody and measured CMV-Hb from erythrocytes in type 2 diabetic patients and healthy control subjects (age 64.6 +/- 12.0 vs. 61.1 +/- 13.2 years, NS: HbA1c 69 +/- 1.5 vs. 5.2 +/- 0.4%, P < 0.0001). RESULTS: A monoclonal antibody against CMV-Hb beta-chain NH2-terminal and an assay method for measurement for CNMV-Hb were both developed in our laboratory. CMV-Hb levels were significantly greater in the diabetic patients than in the control subjects (18.2 +/- 6.9 vs. 12.7 +/- 0.9 pmol CMV/mg Hb, P < 0.0001). No correlation was found between CMV-Hb and HbA1c or CMV-Hb and glycated albumin. Levels of CMV-Hb increased as the diabetic nephropathy progressed. CONCLUSIONS: We established an assay method for CMV-Hb and confirmed the presence of CMV-Hb in circulating erythrocytes. CMV-Hb was more prevalent in diabetic patients than in healthy subjects. Furthermore, it was significantly higher in patients with diabetic nephropathy, suggesting that the presence of CMV-Hb may be a valuable marker for the progression of diabetic nephropathy.

Animals↗
PubMed2001

Mechanisms of photoreceptor cell death in cancer-associated retinopathy.

PURPOSE: In a previous study, both recoverin and heat shock cognate protein (hsc) 70 were recognized as autoantigens by sera from patients with cancer-associated retinopathy (CAR), and retinal dysfunction similar to CAR was inducible by intravitreous injection of anti-recoverin and anti-hsc 70 antibodies to Lewis rat. The purpose of the present study was to elucidate the effects of these antibodies on retinal photoreceptor cell functions, the contribution of caspase during the photoreceptor degeneration, and the roles of aberrant expression of recoverin in tumor cells. METHODS: As photoreceptor functions, rhodopsin phosphorylation using freshly prepared rod outer segments (ROS) and electroretinogram (ERG) were studied. Expression of recoverin in several kinds of tumors was examined by reverse transcription-polymerase chain reaction and Western blot analysis. The effects of recoverin on calcium-dependent protein phosphorylation were studied using the A549 lung adenocarcinoma cell line, which does not express recoverin. RESULTS: Rhodopsin phosphorylation in bovine ROS was significantly promoted by the addition of anti-recoverin antibody. Similar effects on rhodopsin phosphorylation and ERG impairment were observed in rat eyes treated with anti-recoverin antibody. Co-injection of caspase inhibitors with anti-recoverin antibody inhibited ERG impairment and significantly suppressed the antibody-induced enhancement of rhodopsin phosphorylation. Aberrant expression of recoverin was found in 15 of 30 tumor tissues from patients with cancer without CAR. Profiles of calcium-dependent protein phosphorylation of cell lysate from A549 cells were modulated by the presence of purified recoverin. CONCLUSIONS: These observations suggest that anti-recoverin antibody is incorporated into rod photoreceptor cells and modulates rhodopsin phosphorylation, which in turn produces activation of caspase-dependent apoptotic pathways. Regarding antibody generation in CAR, a high incidence of aberrant expression of recoverin in cancer tissues is important, as suggested previously.

Animals↗
PubMed2001

[Autoimmune mechanisms in molecular pathology of glaucomatous optic neuropathy].

BACKGROUND: Glaucomatous optic neuropathy is characterized by loss of retinal ganglion cells and their axons, excavated appearance of the optic nerve head, and progressive loss of visual field sensitivity. In terms of pathology of the glaucomatous optic neuropathy, observations suggest retinal ganglion cell death by apoptosis. Deprivation of neurotrophic factors, ischemia, chronic elevation of glutamate, and disorganized nitric oxide metabolism have been suspected to be mechanisms triggering apoptosis. Another recent suggestion is that autoantibodies directed toward retinal antigens may be involved in facilitating apoptotic cell death in some glaucoma patients. METHOD: We summarized previous reports dealing with the relationship between glaucoma etiology and autoimmune responses, and investigated the contribution of autoimmune factors in glaucomatous optic neuropathy using electrophysiological and biochemical methods. RESULTS: We found serum anti-neuron specific enolase(NSE) antibody in approximately 20% of our glaucoma patients. In primary open angle glaucoma, maximum and mean intraocular pressures in antibody positive patients were significantly or relatively lower than pressures in antibody negative patients. In addition, we also found that apoptotic cell death of retinal ganglion cells was induced in rat eyes by intravitreal administration of purified anti-NSE antibody. CONCLUSION: As suggested by previous reports, autoimmune response is one of the mechanisms related to glaucoma etiology and NSE may have an important function as an autoantigen.

Animals↗
PubMed2001

Immunochemical assay of hemoglobin with N(epsilon)-(carboxymethyl)lysine at lysine 66 of the beta chain.

BACKGROUND: N(epsilon)-(Carboxymethyl)lysine (CML), a well-characterized and major advanced glycation end product structure, is produced via a Maillard reaction by nonenzymatic glycation and/or oxidation. Although few of the carboxymethylation sites of lysine residues on proteins have been identified, it is known that the possible lysine glycation site in hemoglobin (Hb) is Lys-66 on the beta chain. We aimed to develop an assay for the Hb with a CML (CML-Hb) site specific to Lys-66 on the Hb beta chain and to determine whether the lysine residue at that site is carboxymethylated. METHODS: Ala-His-Gly-Lys-Lys(CM)-Val-Leu-Gly-Ala-Phe-Ser-Cys, the peptide derived from the beta chain of human Hb, was synthesized as an immunogen, and a monoclonal antibody against the peptide was prepared. A latex immunoassay method was established using the antibody on an automatic analyzer. In this study, 20 samples from healthy subjects and 80 samples from nondiabetic patients undergoing hemodialysis (HD) were analyzed. RESULTS: The latex immunoassay method using the antibody correlated significantly with the ELISA method using the antibody (r = 0.95; P <0.001). Between healthy subjects (n = 20) and nondiabetic HD patients (n = 80), a significant difference was seen in circulating CML-Hb (525 +/- 76 vs 778 +/- 137 pmol CML/mg of Hb; P <0.0001). CONCLUSION: The latex method for the CML-Hb site specific to Lys-66 on the beta chain can measure large numbers of samples on an automatic analyzer.

Acetaldehyde↗
PubMed2001

Retinal dysfunction in cancer-associated retinopathy is improved by Ca(2+) antagonist administration and dark adaptation.

PURPOSE: It was recently found that recoverin acts as an autoantigen recognized by sera of patients with cancer-associated retinopathy (CAR), and that CAR-like retinal dysfunction is produced by intravitreous administration of anti-recoverin antibody in Lewis rat eyes. To examine the pathologic molecular mechanism of CAR, and to elucidate an effective therapy for CAR, the function and morphology of CAR were compared with those of phototoxic retinal damage, another form of photoreceptor dysfunction, and the effect of nilvadipine, a Ca(2+) antagonist, on the retinal degenerations was studied, using these models. METHODS: Under different illumination conditions and/or medication with nilvadipine, the functional and morphologic properties of the retinas were evaluated after intravitreous injection of anti-recoverin antibody into Lewis rat eyes (six rats, 12 eyes in each experimental condition), using electroretinogram (ERG), rhodopsin phosphorylation, and light microscopy. RESULTS: Anti-recoverin antibody administered into the vitreous of Lewis rat eyes induced a significant decrease and increase of ERG responses and rhodopsin phosphorylation levels, respectively, under cyclic or continuous light. Similar changes were observed in eyes of rats bred under continuous illumination that did not receive anti-recoverin antibodies. However, anti-recoverin antibody-induced retinal dysfunctions were not observed in rat eyes under dark conditions. Administration of nilvadipine, a Ca(2+) antagonist, to the anti-recoverin antibody-treated rats and rats with phototoxic retinal dysfunction caused significant improvement of the deterioration of ERG and normalization of rhodopsin phosphorylation. CONCLUSIONS: The present data indicate that anti-recoverin antibody-induced retinal dysfunction was functionally similar to phototoxic retinal dysfunction and was markedly suppressed under dark conditions or by systemic administration of a Ca(2+) antagonist.

Animals↗