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Biomedical subjects

N Maruyama

Publications and source records attributed to N Maruyama.

At least 19 recordsLinked to original sources
PubMed2006

Accelerated tubular cell senescence in SMP30 knockout mice.

An experimental model with accelerated but not drastic renal senescence seemed useful to recognize the mechanisms of how kidney function deteriorates with age. Senescence marker protein-30 (SMP30), whose expression decreased with age and was sex-independent, is mainly expressed in hepatocytes and proximal tubular cells. Therefore, we established a SMP30 deficient strain of mice with a C57BL/6 background by gene targeting to investigate whether this molecule is involved in renal tubular cell senescence. Male SMP30 knockout (SMP30Y/-) mice and male wild-type (SMPY/+) mice (n=5) aged 12 months were examined histologically. Their tubular epithelia showed the deposition of lipofuscin and the presence of senescence-associated beta-galactosidase (SA-beta-GAL). However, no tubular cells were atrophic. In electron microscopy, SMP30-KO mice showed markedly enlarged lysosomes containing an electron dense substance. These are convincing hallmarks of senescence. We recognized the early manifestation of senescence hallmarks in SMP30-KO mice at 12 months old. Thus, this model represents the first report of a mouse strain that manifests accelerated ordinal senescence in a kidney after gene manipulation.

Animals↗
PubMed2005

Elevated macrophage migration inhibitory factor (MIF) levels in the urine of patients with focal glomerular sclerosis.

The pathogenesis of focal glomerular sclerosis (FGS) is poorly understood. Macrophage migration inhibitory factor (MIF) is a potent pro-inflammatory cytokine released from T cells and macrophages, and is a key molecule in inflammation. To examine further the possible role of MIF in FGS, we measured MIF levels in the urine. The purpose of the present study was to evaluate the involvement of MIF in FGS. Urine samples were obtained from 20 FGS patients. The disease controls included 40 patients with minimal-change nephrotic syndrome (MCNS) and membranous nephropathy (MN). A group of healthy subjects also served as controls. Biopsies were performed in all patients prior to entry to the study. The samples were assayed for MIF protein by a sandwich enzyme-linked immunosorbent assay (ELISA). The levels of MIF in the urine of FGS patients were significantly higher than those of the normal controls and patients with MCNS and MN. In contrast, the levels of urinary MIF (uMIF) in patients with MCNS and MN did not differ significantly from normal values. In the present study, attention also focused on the relationship between uMIF levels and pathological features. Among the patients with FGS, uMIF levels were significantly correlated with the grade of mesangial matrix increase and that of interstitial fibrosis. There was also a significant correlation between uMIF levels and the number of both intraglomerular and interstitial macrophages. Although the underlying mechanisms remain to be determined, our study presents evidence that urinary excretion of MIF is increased in FGS patients with active renal lesions.

Adult↗
PubMed2005

Immunohistochemical localization of senescence marker protein-30 (SMP30) in the submandibular gland and ultrastructural changes of the granular duct cells in SMP30 knockout mice.

Senescence Marker Protein-30 (SMP30) is a calcium-regulating protein that decreases in an androgen-independent manner as aging occurs. An enzyme-labeled antibody technique has demonstrated that SMP30 localized to the ducts (granular, intercalated, and striated ducts) of mouse submandibular glands. Immunoelectronmicroscopy demonstrated that the granular duct cells were strongly positive for SMP30, but that pillar cells in the granular duct were negative for the protein. In SMP30-knockout (KO) mice, the granular ducts were smaller in diameter. Swelling of mitochondria in the granular duct cells was observed; however, this phenomenon was not observed in the pillar cells. After administration of alpha-isoproterenol, a beta-adrenergic stimulant, a large numbers of small secretory granules were present in the granular duct cells and an expansion of the rough endoplasmic reticulum in SMP30-wild type (WT) mice; in contrast, little change was observed in SMP30-KO mice. These results suggest that SMP30 may be closely related to a signal transduction pathway in the granular duct cells of submandibular glands.

Animals↗
PubMed2001

Design and production of genetically modified soybean protein with anti-hypertensive activity by incorporating potent analogue of ovokinin(2-7).

The potent anti-hypertensive peptide, RPLKPW, has been designed based on the structure of ovokinin(2-7). The sequence encoding this peptide was introduced into three homologous sites in the gene for soybean beta-conglycinin alpha' subunit. The native alpha' subunit as well as the modified, RPLKPW-containing alpha' subunit were expressed in Escherichia coli, recovered from the soluble fraction and then purified by ion-exchange chromatography. The RPLKPW peptide was released from recombinant RPLKPW-containing alpha' subunit after in vitro digestion by trypsin and chymotrypsin. Moreover, the undigested RPLKPW-containing alpha' subunit given orally at a dose of 10 mg/kg exerted an anti-hypertensive effect in spontaneously hypertensive rats, unlike the native alpha' subunit. These results provide evidence for the first time that a physiologically active peptide introduced into a food protein by site-directed mutagenesis could practically function in vivo even at a low dose.

Administration, Oral↗
PubMed2001

Involvement of calcium signaling in the fibronectin-stimulated macrophage recognition of oxidatively damaged erythrocytes.

Macrophages recognize oxidatively damaged autologous erythrocytes, and cell surface fibronectin of macrophages enhances the recognition (Beppu et al., FEBS Lett. 295 (1991) 135-140). In the present study, mechanisms of enhanced macrophage recognition of oxidatively damaged erythrocytes by fibronectin were investigated. Monolayers of thioglycollate-induced mouse peritoneal macrophages with cell surface fibronectin recognized autologous erythrocytes oxidized with an iron catalyst ADP/Fe(3+). The macrophage recognition of the oxidized erythrocytes was inhibited partially by pretreatment of the macrophage monolayers with a Ca(2+) channel blocker (diltiazem), calmodulin inhibitors (W-7, trifluoperazine, chlorpromazine and dibucaine), an inhibitor of myosin light chain kinase (ML-9), a microfilament formation inhibitor (cytochalasin B), phospholipase A(2) inhibitors (4-bromophenacyl bromide, mepacrine) and cyclooxygenase inhibitors (indomethacin and aspirin). Monolayers of macrophages depleted of fibronectin by trypsinization lost the ability of recognizing oxidized erythrocytes, but acquired the ability when stimulated with a fibronectin-coated coverslip. The recognition of fibronectin-stimulated trypsinized macrophages was also inhibited by the above inhibitors. On treatment with Ca ionophore A23187, trypsinized macrophages acquired the ability to recognize oxidized erythrocytes. The recognition of Ca ionophore-stimulated trypsinized macrophages was inhibited by the above inhibitors except the Ca(2+) channel blocker. These results indicate that the Ca(2+) signaling including Ca(2+) influx, calmodulin activation and myosin light chain phosphorylation are involved in the fibronectin stimulation of the recognition of macrophages for oxidized erythrocytes. Involvement of microfilament formation and arachidonate cascade in the fibronectin stimulation was also suggested.

Animals↗
PubMed2001

Acute epidural hematoma related to cesarean section in a neonate with Chiari II malformation.

We present a rare case of acute epidural hematoma in a newborn infant with congenital hydrocephalus that was related to Chiari II malformation. The hematoma was attributed to the application of excessive suction with a vacuum extractor during cesarean section. The clinical characteristics of neonatal epidural hematoma were analyzed after a review of 18 cases in the literature, and diagnosis and treatment are discussed with reference to the results. We propose that careful follow-up is essential in neonates with cephalohematoma, and that a computed tomography (CT) study should be performed immediately if an infant's head circumference is discovered to be enlarging or if the anterior fontanel bulges.

Arnold-Chiari Malformation↗
PubMed2001

Synthesis and stereostructure-activity relationship of three asymmetric center pyrethroids: 2-methyl-3-phenylcyclopropylmethyl 3-phenoxybenzyl ether and cyanohydrin ester.

2-Methyl-3-phenylcyclopropylmethyl 3-phenoxybenzyl ether 2 and cyanohydrin ester 3, a couple of pyrethroids with three asymmetric centers, were synthesized. Of each of the four diastereomers of 2 and 3, only the (1R*,2R*,3R*)-2a and 3a showed significant insecticidal activities. Dual sets of enantiomers [(1R,2R,3R)-(-)-2a and (1S,2S,3S)-(+)-2a] and [(1R,2R,3R)-(-)-3a and (1S,2S,3S)-(+)-3a] were synthesized through the asymmetric cyclopropanation using the Aratani catalyst. Significant separations of insecticidal activities were observed between both the enantiomers against the tobacco cutworm (Spodoptera litura) and the common mosquito (Culex pipiens pallens); (1S,2S,3S)-(+)-2a and (+)-3a showed higher activities than their antipodes (1R,2R,3R)(-)-2a and (-)-3a. This result is the second example of such synthetic pyrethroids with three asymmetric centers.

Animals↗
PubMed2001

Crystal structures of recombinant and native soybean beta-conglycinin beta homotrimers.

The crystal structures of recombinant and native beta homotrimers of soybean beta-conglycinin were determined by X-ray crystallography at 2.7 and 2.8 A resolutions, respectively. The crystals of the recombinant and native beta homotrimers belong to space group P21 with cell parameters a = 80.51 A, b = 63.48 A, c = 131.43 A, and beta = 90.01 degrees and with cell parameters a = 82.78 A, b = 69.47 A, c = 125.33 A and beta = 97.22 degrees, respectively. The beta monomers consist of amino-terminal and carboxyl-terminal modules that are very similar to each other and are related by a pseudo-dyad axis. Each module of the beta monomer is subdivided into a core and a loop domain. These structural features of both beta homotrimers are consistent with those of canavalin and phaseolin, which are similar vicilin class proteins. The superposition of the models of the native and recombinant beta monomers shows a root mean square deviation of 0.43-0.51 A for 343 common Calpha atoms within 2.0 A. This result indicates that the N-linked glycans do not influence the final structure of the beta homotrimer. Comparison of the models of beta-conglycinin, phaseolin and canavalin indicates that beta-conglycinin resembles canavalin rather than phaseolin, and that canavalin and phaseolin differ the most among them. The evolutional relationships are discussed.

Amino Acid Sequence↗
PubMed2001

Regulatory effects of senescence marker protein 30 on the proliferation of hepatocytes.

Senescence marker protein 30 (SMP 30) is preferentially expressed in the liver. One of its remarkable functions is the protection of cells against various injuries by enhancement of membrane calcium-pump activity. We analyzed the role of SMP 30 in hepatocyte proliferation. SMP 30 expression was decreased initially, then increased along with hepatic regeneration, after carbon tetrachloride (CCl4) administration. SMP 30 expression was decreased in the necrotic phase and then gradually increased. Its increase was slightly delayed just after the mitotic phase. These results lead us to speculate that mitoses of hepatic cells induce enhanced SMP 30 expression. In contrast, administration of lead nitrate (LN) as a hepatic mitogen induced a more stable increase of SMP 30 expression. To estimate the effect of SMP 30 on cell proliferation, we evaluated hepatic mitosis in wild-type and SMP 30-deficient knockout (KO) mice after CCl4 administration. We found an increase in mitotic numbers in hepatocytes of KO mice. This result suggests that SMP 30 has a suppressive effect on cell proliferation. Suppressive activity of SMP 30 cDNA was shown in cultured hepatoblastic cells. Our results suggest that SMP 30 performs a regulatory function in liver regeneration.

Animals↗
PubMed2001

Expression of Bcl-2 and Bax in hypokalemic nephropathy in rats.

OBJECTIVES: Potassium depletion results in hyperplasia of renal tubular and interstitial cells in humans and animals, and potassium repletion induces rapid regression of hyperplasia. Apoptosis participates importantly in this reduction of cell number, although we have observed tubular and interstitial apoptosis in rats during potassium depletion as well. METHODS: To investigate mechanisms of apoptosis in this model, we assessed expression of Bcl-2 and Bax, using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Cell proliferation identifiable by labeling with 5-bromo 2'-deoxyuridine was prominent in tubular and interstitial cells of the cortex and outer medulla (OM) 7 days after potassium depletion. Simultaneously present apoptotic cells identified by light microscopy, electron microscopy, and nick end labeling were located mainly in the OM. Seven days after potassium repletion, apoptotic cells increased again but proliferating cells decreased. Bcl-2 protein distributed in the tubules of the OM was significantly decreased in potassium-depleted and potassium-repleted rats compared with control rats, while immunoreactivity for Bax protein tended to increase above control levels in potassium-depleted rats. RT-PCR for bcl-2 and bax demonstrated a significant decrease in levels of bcl-2 mRNA in potassium-depleted and potassium-repleted rats relative to those in controls. Expression of bax mRNA in potassium-depleted and potassium-repleted rats tended to increase, while ratios of bcl-2 mRNA to bax mRNA significantly decreased. CONCLUSIONS: These results suggest that apoptosis is associated with progression and regression of cellular proliferation in hypokalemic nephropathy, and a decrease in Bcl-2 may be involved in promoting this apoptotic process.

Animals↗
PubMed2001

Quantitative analyses of messenger RNA of human endogenous retrovirus in patients with systemic lupus erythematosus.

OBJECTIVE: Human endogenous retrovirus (HERV) has emerged as a possible causative agent of systemic lupus erythematosus (SLE). To investigate the role of HERV in the etiology of SLE, we performed quantitative analyses of messenger RNA (mRNA) of the HERV clone 4-1 in patients with SLE. METHODS: Reverse transcriptase (RT)-polymerase chain reaction (PCR) and real-time quantitative PCR (RQ-PCR; TaqMan methodology) were used in this experiment. RESULTS: The quantities of mRNA of the HERV clone 4-1 gag region in patients with SLE were significantly higher than in healthy controls, and the amounts of such mRNA in the patients were decreased by steroid treatment. CONCLUSION: These phenomena may be related to the production of viral components derived from HERV clone 4-1 and contribute to the pathogenesis of SLE; studies using a larger number of patients are required to confirm these points.

Adult↗
PubMed2001

[A patient with esophageal cancer with subcutaneal abscess and esophago-tracheal fistula who survived more than 2 years following treatment by drainage and chemoradiation therapy].

A 48-year-old man presented at the hospital because of neck swelling and pain. A diagnosis of esophageal cancer with subcutaneous abscess was made based on examination and biopsy results. The cancer was Ce T4NxMx Stage III-IVa. Curative surgery was considered impossible, so chemoradiation therapy was performed (5-FU 500 mg + CDDP 5 mg/day + 2 Gy/day x 31 days) after drainage. During the therapy, an esophago-tracheal fistula was observed, but it later vanished. After chemoradiation therapy, the abscess and tumor vanished. No serious adverse reactions were observed. Now, 2 years after therapy, no recurrence has been found. The patient is now in good health with no symptoms and undergoes regular check-ups. Chemoradiation therapy is effective for inoperable advanced esophageal cancer.

Abscess↗
PubMed2001

[Diagnosis of the postoperative local recurrence of rectal cancer by FDG-PET--a case report].

Positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) as the tracer of glucose metabolism was performed to identify a postoperative recurrent lesion of rectal cancer. A 66-year-old-man underwent trans-sacral local resection of the rectum for rectal cancer in 1992. A local recurrent mass was discovered, and abdomino-perineal resection of the rectum was performed in 1999. The serum CEA level increased gradually August in 2000, but there was no sign of recurrence on CT or MRI. FDG-PET was performed to reveal a presacral recurrent lesion. Total pelvic evisceration combined with resection of the sacrum, and a bilateral ureterostomy were performed in April 2001. The beneficial role of FDG-PET in the diagnosis of the postoperative local recurrence of rectal cancer is emphasized.

Adenocarcinoma↗
PubMed2001

[A case of recurring breast cancer causing pericardial metastasis showing a good response following local treatment with methotrexate].

A 52-year-old woman was admitted with a chief complaint of dyspnea. She had undergone right mastectomy for Stage IIB breast cancer 2 years and five months earlier. Chest roentgenogram revealed cardiomegaly and bilateral pleural effusion, and a cardiac echogram showed marked retention of pericardial effusion. A diagnosis of cardiac tamponade was made and pericardiocentesis for continuous drainage was carried out cytologically, the effusion was class V and showed evidence of pericardial metastasis of breast cancer. Pericardiocentesis followed by methotrexate instillation 6 times in a dose of 110 mg successfully controlled the cardiac tamponade, after which the catheter could be removed from the pericardial space. Systemic chemotherapy (CEF) was started at the same time. The patient was discharged very much improved after these treatments, but she died of brain metastasis after 9 months. This case suggests that intrapericardial application of methotrexate may be very useful in the management of carcinomatous cardiac tamponade without any serious side effects.

Antimetabolites, Antineoplastic↗