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S Maeda

Publications and source records attributed to S Maeda.

At least 199 records · Page 11Linked to original sources
PubMed1999

Promoter structure of mouse RANKL/TRANCE/OPGL/ODF gene.

Receptor activator of NF-kappa B ligand (RANKL)/tumor necrosis factor-related activation induced cytokine (TRANCE)/osteoprotegerin ligand (OPGL)/osteoclast differentiation factor (ODF) is a membrane-bound signal transducer responsible for differentiation and maintenance of osteoclasts. To elucidate the mechanism regulating RANKL/TRANCE/OPGL/ODF gene expression, we cloned the 5'-flanking basic promoter region of the mouse RANKL/TRANCE/OPGL/ODF gene and characterized it by transient transfection studies and genomic Southern blot analysis. Inverted TATA- and CAAT-boxes and a putative Cbfa1/Osf2/AML3 binding domain constituted the basic promoter structure. The repeated half-sites for the vitamin D3 (VitD3) and glucocorticoid receptors were located at -935 and -640, respectively. Transient transfection studies revealed that short-term treatment with 1alpha,25(OH)2 VitD3 or dexamethasone increased luciferase activity up to 204% and 178%, respectively; on the other hand, treatment with dibutyryl cyclic AMP did not affect the promoter activity. Since the expression of Cbfa1/Osf2/AML3 is also regulated by VitD3, 1alpha,25(OH)2 VitD3 might affect RANKL/TRANCE/OPGL/ODF gene expression both directly and indirectly. CpG methylation was observed dominantly in mouse stromal cells, ST2, of a later passage which ceased to support in vitro osteoclastogenesis, suggesting that the methylation status of the CpG loci in the RANKL/TRANCE/OPGL/ODF gene promoter may be one of the influential cis-regulating factors.

Animals↗
PubMed1999

Rotational Digital Angiography for the Evaluation of Iliac Artery Disease.

Ten cases with iliac artery disease were evaluated using rotational angiography with revolution of the arm of the X-ray tube support unit. The tip of the catheter was advanced to the infrarenal aorta, and contrast medium was injected at a rate of 6-10 ml/second. Digital angiographic images from multiple projection angles were acquired at 15 frames/second with a rotation speed at about 10 degrees/second and a range of greater than 90 degrees. This method made it possible to detect ulcerations of the artery, which could not be visualized using conventional single-plane angiography. The three-dimensional structure of a dissection could also be visualized. In seven cases of occlusive iliac artery disease, comparison with rotational angiography revealed that anteroposterior views of single-plane angiography underestimated the extent of the disease in four cases and overestimated the extent of the disease in one case. In two cases, no additional clinical information was obtained. In conclusion, rotational angiography provides accurate three-dimensional information concerning the lumen of the iliac arteries.

Journal Article↗
PubMed1999

Intracortical osteoblastic osteosarcoma with oncogenic rickets.

Intracortical osteosarcoma is the rarest variant of osteosarcoma, occurring within, and usually confined to, the cortical bone. Oncogenic osteomalacia, or rickets, is an unusual clinicopathologic entity in which vitamin D-resistant osteomalacia, or rickets, occurs in association with some tumors of soft tissue or bone. We present a case of oncogenic rickets associated with intracortical osteosarcoma of the tibia in a 9-year-old boy, whose roentgenographic abnormalities of rickets disappeared and pertinent laboratory data except for serum alkaline phosphatase became normal after surgical resection of the tumor. Histologically, the tumor was an osteosarcoma with a prominent osteoblastic pattern. An unusual microscopic feature was the presence of matrix mineralization showing rounded calcified structures (calcified spherules). Benign osteoblastic tumors, such as osteoid osteoma and osteoblastoma, must be considered in the differential diagnosis because of the relatively low cellular atypia and mitotic activity of this tumor. The infiltrating pattern with destruction or engulfment of normal bone is a major clue to the correct diagnosis of intracortical osteosarcoma. The co-existing radiographic changes of rickets were due to the intracortical osteosarcoma.

Bone Neoplasms↗
PubMed1999

In situ hybridization with polymerase chain reaction-derived single-stranded DNA probe and S1 nuclease.

A rapid and simplified protocol for in situ hybridization (ISH) with polymerase chain reaction (PCR)-derived single-stranded DNA probes and S1 nuclease revealed transcripts of bone matrix proteins on decalcified skeletal bone specimens. Mouse bone tissue was fixed with 4% paraformaldehyde, decalcified with 20% EDTA, and embedded in paraffin. Each pair of primers for reverse transcriptase -PCR was designed to amplify a 280-bp DNA fragment from the coding region of the mature protein of mouse osteonectin (ON) and a 320-bp fragment from the coding region of mouse osteopontin (OP). Initial PCR products were eluted, purified, and reamplified by unidirectional PCR in the presence of the digoxigenin (DIG)-labeled dUTP. ISH was carried out by proteinase K treatment, hybridization, and washing. The unhybridized single-stranded DNA probe was selectively removed by S1 nuclease treatment. Hybridized probes were visualized with the alkaline phosphatase-conjugated anti-DIG antibody. The transcripts of ON and OP were clearly detected on the thin sections of the decalcified bone. Because this protocol does not require cloning or in vitro transcription, reliable and stable ISH can be done in an ordinary laboratory equipped with a thermal cycler.

Animals↗
PubMed1999

Expression of platelet-derived growth factor proteins and their receptor alpha and beta mRNAs during fracture healing in the normal mouse.

Platelet-derived growth factor (PDGF), abundant in bone tissue, has been reported to stimulate mesenchymal cell proliferation and migration. To elucidate the functional roles of PDGF during fracture healing, we investigated the expression of PDGF-A and -B chain proteins and receptor alpha and beta mRNAs in fractured mouse tibiae. Twelve-week-old male BALB/c mice were operated on to make a closed fracture on the proximal tibia. On days 2, 4, 7, 10, 14, 21, and 28 after the operation, the fractured tibiae were excised, fixed with 4% paraformaldehyde, decalcified with 20% EDTA, and embedded in paraffin to prepare 7-microm sections. Immunohistochemistry using polyclonal antibodies against human PDGF-A and -B chains was carried out by the avidin-biotin-peroxidase method. For in situ hybridization, we used digoxigenin-labeled single-stranded DNA probes specific for mouse PDGF receptors alpha and beta generated by unidirectional polymerase chain reaction. In the inflammatory phase on days 2-4 after the fracture, mesenchymal cells gathering at the fracture site expressed the PDGF-B chain and beta receptor mRNA. At the stage of cartilaginous callus formation on day 7, the immunoreactivity for PDGF-A and -B chains on proliferating and hypertrophic chondrocytes and the signals of alpha and beta receptor mRNAs on proliferating chondrocytes became manifest. At the stage of bony callus and bone remodeling on days 14-21, the predominant expression of the PDGF-B chain and beta receptor was observed on both osteoclasts and osteoblasts. On day 28, signals for PDGF ligand proteins and receptor mRNAs diminished. The coincidental localization of PDGF ligands and their receptors implies a paracrine and autocrine mechanism. Our data suggested that PDGF contributed in part to the promotion of the chondrogenic and osteogenic changes of mesenchymal cells from the early to the midphase of fracture healing; the functions mediated by the beta receptor, including cell migration, might be prerequisites to the recruitment of mesenchymal cells in the initial step and to the interaction between osteoclasts and osteoblasts in the bone remodeling phase.

Animals↗
PubMed1999

In situ demonstration of parathyroid hormone-related protein mRNA in sclerosing hepatic carcinoma.

A 69-year-old man had a hepatic tumour occupying the left and half of the right lobe, with portal vein thrombus. There were hypercalcaemia and hypophosphataemia with increased nephrogenous cyclic adenosine monophosphate; bone metastases were excluded. Serum parathyroid hormone-related protein (PTHrP) was elevated, but no increase in intact parathyroid hormone (PTH) or vitamin D3 metabolites was found. At autopsy the histological features were typical of sclerosing hepatic carcinoma. By immunohistochemistry PTHrP was detected in cancer cell nests but not in the fibrous stroma. PTHrP transcripts were demonstrated by in situ hybridization using a polymerase chain reaction (PCR)-derived single-stranded DNA probe. Tumour cells expressed AE1 and CA19-9 (markers for cholangioepithelium) and CEA (for bile canaliculi). Electron microscopy revealed microvilli on the apical surface, and secretory granules 100 nm in diameter were observed. These findings indicate that this case is one of cholangiocellular sclerosing hepatic carcinoma. The interaction between cancer and stromal cells may be the cause of PTHrP overexpression.

Aged↗
PubMed1999

Synaptology and ultrastructural characteristics of laryngeal cricothyroid and posterior cricoarytenoid motoneurons in the nucleus ambiguus of the rat.

The laryngeal motoneurons innervating the cricothyroid muscle (CT) are located in the semicompact formation just ventral to the rostral part of the compact formation of the nucleus ambiguus. The motoneurons innervating the posterior cricoarytenoid muscle (PCA) are located in the loose formation. We retrogradely labeled the CT and the PCA motoneurons using cholera toxin subunit B-conjugated horseradish peroxidase, and determined the ultrastructure and synaptic organization of these neurons. The CT and the PCA motoneurons had the appearance of alpha-motoneurons, i.e., large, oval or polygonal cells containing well-developed organelles and a prominent spherical nucleus. Two kinds of neurons were recognized among the PCA motoneurons. The one (PCA-A) was significantly smaller than the other (PCA-B). The average number of axosomatic terminals in a section was significantly largest in the PCA-B (56.6), smaller in the PCA-A (36.0), and smallest in the CT (32.3) neurons. Most of the axosomatic terminals (64.7%) contained pleomorphic vesicles and made symmetric synaptic contacts (Gray's type II) with the PCA-A neurons, while more than 60% contained round vesicles with asymmetric synaptic contacts (Gray's type I) in the CT (69.5%) and the PCA-B (60.6%) neurons. A few terminals associated with subsurface cisterns were present on all laryngeal motoneurons. These results indicated that the CT motoneurons may receive mostly excitatory terminals, whereas the PCA muscle may be regulated by neurons having many inhibitory terminals, and neurons having many excitatory terminals.

Animals↗
PubMed1999

Molecular characterization of baculovirus Bombyx mori nucleopolyhedrovirus polyhedron mutants.

Four newly isolated and two previously isolated polyhedron mutants of Bombyx mori nucleopolyhedrovirus (BmNPV) were studied. Two polyhedron deficient mutants, #126 and #136, produced small uncrystallized particles of polyhedrin in the nuclei and cytoplasm of infected cells. Mutant #211 produced a large number of variably sized polyhedra in the nucleus and #220 produced a few large cuboidal polyhedra in the nucleus. Mutant #24 and #128 were previously isolated BmNPV mutants. Mutant #24 could not produce polyhedrin mRNA and polyhedra produced by mutant #128 lacked oral infectivity. Nucleotide sequence analysis indicated that five mutants (#126, #136, #211, #220 and #128) had amino acid substitutions in polyhedrin and mutant #24 had a point mutation only in the promoter region of the polyhedrin gene. Cotransfection experiments showed that the altered phenotypes were due to the mutations found in the polyhedrin gene regions. In mutants #126 and #136, amino acid sequences of the nuclear localization signal of polyhedrin were identical to those of wild-type BmNPV, suggesting that this sequence was necessary but not sufficient for nuclear localization of polyhedrin. Electron microscopic observation revealed that fewer occluded virions were contained in polyhedra of #128 and #220.

Animals↗
PubMed1999

Myocardial expression of endothelin-2 is altered reciprocally to that of endothelin-1 during ischemia of cardiomyocytes in vitro and during heart failure in vivo.

We and other groups have reported that endothelin (ET)-1 expression in the heart is altered in the setting of heart diseases. We have also reported that myocardial ET-1 is involved in the progression of heart failure, and that an ET receptor antagonist improves long-term survival in heart failure (Nature 384: 353-355, 1996). However, the role of myocardial ET-2 in disease states are not known. To characterize the role of ET-2, we used a) the failing hearts of rats with heart failure caused by myocardial infarction, and b) primary cultured cardiomyocytes subjected to hypoxia. In the failing heart in vivo, ET-1 mRNA increased by 390% compared with that in the non-failing heart, while ET-2 mRNA drastically decreased by 88%. Thus, gene expression of ET-1 and ET-2 was reciprocally altered in the failing heart in vivo. In in vitro studies, reciprocal alterations in ET-1 and ET-2 gene expression were also observed in isolated primary cultured cardiomyocytes, subjected to hypoxia. Specifically, acute hypoxic stress induced a significant increase (360% of the basal level) in ET-2 mRNA expression compared with that in normoxic cells, whereas it decreased ET-1 mRNA expression by 62% in primary cultured cardiomyocytes. Although these two crucial conditions, i.e., heart failure in vivo and acute hypoxic stress in vitro, are pathophysiologically distinct from each other, reciprocal alteration of ET-1 and ET-2 gene expression was observed in both cases. To further investigate the regulatory mechanism of the altered gene expression, luciferase analysis was performed using primary cultured cardiomyocytes. ET-2 promoter, which is the 5'-flanking region of preproET-2 gene (5'ET-2), showed a marked increase in luciferase activity during acute hypoxia. In contrast, the luciferase activity of 5'ET-1 (ET-1 promoter) did not change in response to hypoxic stress. The present study suggests that there are transcriptionally distinct regulatory mechanisms for ET-1 and ET-2 expression in cardiomyocytes, and therefore this study may provide a new aspect of cardiac ET system that not only ET-1 but also ET-2 can be participated in the pathophysiological conditions.

Animals↗
PubMed1999

Kininogens and kallikrein in pruritic papular eruption.

Pruritic papular eruption (PPE) is a common inflammatory cutaneous lesion observed only in HIV/AIDS patients. Since kinin is an important mediator in inflammation, we evaluated the levels of total kininogen (TKg), low and high molecular weight kininogen (LKg and HKg, respectively) and the activity of kallikrein in plasma of 11 patients (median age = 31.4) with AIDS and PPE (PPE+), eight patients (median age = 31.5) with AIDS without PPE (PPE-) and in 12 control individuals (median age = 32.9) with anti-HIV negative serum. Kininogens were measured by ELISA and expressed in median (m) of BK Equivalent/ml plasma and the kallikrein by its activity upon selective chromogenic substrate, and expressed as U kallikrein/ml of plasma. TKg or LKg concentrations in PPE+ patients (m = 4.11 and 4.5) and in PPE- patients (m = 6.23 and 4.54) were significantly higher when compared to control (m = 2.10 and 1.17). Compared to controls PPE- patients presented similar values of HKg (m = 0.78 and 0.61), whereas PPE+ patients presented undetectable values. Plasma kallikrein activity was significantly decreased in PPE+ and PPE- (m = 0.6 and 0.89, respectively) when compared with control individuals (m = 2.23).

Adolescent↗
PubMed1999

p130cas is a cellular target protein for tyrosine nitration induced by peroxynitrite.

We found that the exposure of human neuroblastoma SH-SY5Y cells to the peroxynitrite donor 3-morpholinosydnonimine (SIN-1) induced tyrosine nitration of a 130-kDa protein, and prevented tyrosine phosphorylation of the 130-kDa protein. The focal adhesion protein p130cas was identified as a component of the 130-kDa protein using specific antibody. These results suggest that p130cas is a new target protein for nitration induced by SIN-1.

Crk-Associated Substrate Protein↗
PubMed1999

Involvement of calcineurin in the signal transduction of PBAN in the silkworm, Bombyx mori (Lepidoptera).

In several moth species sex pheromone production in the pheromone gland is regulated by a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN). In Bombyx mori it is suggested that PBAN, after binding to the cell-surface receptor, primarily activates a plasma membrane receptor-activated Ca2+ channel to increase cytosolic levels of Ca2+, and Ca2+/calmodulin complex directly or indirectly activates a phosphoprotein phosphatase, which in turn elicits activation of acyl CoA reductase (the key enzyme under PBAN control) through dephosphorylation, resulting in pheromone (bombykol) production. The effect of cyclosporin A (CsA) and FK 506, specific inhibitors of calcineurin (phosphoprotein phosphatase 2B) was studied on the sex pheromone production, in B. mori. The in vitro experiments showed that both chemicals exerted a dose-dependent inhibitory action when they were co-incubated with TKYFSPRL amide (Hez-PBAN fragment peptide). Practically, no difference was detected between the two chemicals in the tested doses (0.025-1250 microM). When effects of CsA or FK 506 were studied on cell-free production of bombykol by using microsomal fraction no inhibition was detected. Since microsomal fraction contains the acyl CoA synthetase, the rate-limiting acyl CoA reductase and the precursor, bombykol is produced if supplied with CoA, ATP and NADPH. Thus, the inhibitory action of CsA and FK506 under in vitro conditions should occur before the step of acyl group reduction and the effect is likely to be attributable to the inhibition of calcineurin in the signal transduction cascade mechanism of PBAN, in B. mori. The existence of calcineurin in the pheromone gland by using Western blot analysis is also demonstrated.

Animals↗
PubMed1999

Physicochemical properties of amorphous clarithromycin obtained by grinding and spray drying.

In order to characterize the amorphous clarithromycin (CAM) obtained by grinding and spray drying, physicochemical properties (crystallinity, thermal behavior, stability and solubility parameters) were evaluated. From powder X-ray diffraction, it was estimated that the crystalline state of CAM was changed into an amorphous state by grinding and spray drying. In differential scanning calorimetry measurements, both broad and sharp peaks for crystallization were observed in ground samples, whereas spray dried samples showed one broad peak due to crystallization. As to the stability test under high humidity, structural difference was confirmed between ground CAMs and spray dried CAM. The heat of dissolution of ground CAMs was greater than that of intact CAM. In the solubility parameter measurement, the increase of the special term, deltas, indicated that the energy change was due to the polarity of the surface energy of the powder particles by grinding.

Anti-Bacterial Agents↗
PubMed1999

Communication between the axillary and radial nerves in the human upper arm.

The communication between the axillary (Ax) and the radial (R) nerves, which was observed in eight upper arms from 602 arms of 301 Japanese cadavers, was studied to determine its origin and distribution. The brachial plexus and spinal segments contributing to the Ax and R in all cases where communication occurred had no distinct differences from those in cases having no communication. According to the direction, the communication is divided into two groups: the communication from the Ax to R (7 cases) and vice versa (2 cases). One specimen had both groups of communication. The origin of communicating branches in these groups extended into the overlapping area (C5 + 6) of the origin of the Ax with that of the R, mainly from the ventral layer of the posterior cord from C6. The distribution of the communicating branch varied in development according to specimens. The communication from the Ax to R has a tendency to invade, from proximally to distally, the distribution of the muscular branches of the R to the radial extensor muscles of the forearm including the supinator muscle. However, the development into the cutaneous branches has no distinct inclination. These findings in humans and some other comparative anatomical descriptions show that in phylogeny the radial extensor muscles of the forearm have a different origin from other extensor muscles of the forearm and have a close relationship with the Ax. Therefore, the communication between the Ax and R holds an important clue in clarifying the morphological significance of the extensor nerves and muscles of the forearm.

Arm↗
PubMed1999

Real time assessment of myocardial revascularization during coronary artery bypass surgery by means of ultrasonic integrated backscatter.

OBJECTIVE: The recovery of cyclic variation (CV) of ultrasonic integrated backscatter (IB) may provide a more sensitive predictor of the success of myocardial revascularization. This study was designed to elucidate the possibility of real time assessment of coronary artery bypass grafting (CABG) using CV of IB. METHODS: We studied 10 patients (61 +/- 4 years old) with the perfused areas by stenosed or occluded LAD without myocardial infarction. There were six ischemic dysfunctional areas, and four ischemic but non-dysfunctional areas. The CV of IB was measured before and just after extracorporeal circulation (ECC). Wall motion was analyzed by segmental wall thickening during systole at the same time of the IB analysis during CABG and at 3 weeks after CABG. Those 10 areas were completely revascularized. RESULTS: In the non-dysfunctional areas, wall thickening did not change and remained at normal values before and after ECC, and 3 weeks after CABG (31 +/- 3% 29 +/- 3% and 29 +/- 5%, respectively). The magnitude of CV of IB did not also change before and after ECC (8.0 +/- 1.6 dB and 7.8 +/- 1.3 dB). However, in the ischemic dysfunctional areas, while wall thickening did not change before and after ECC (21 +/- 5% and 20 +/- 5%), it increased and reached similar values as the non-dysfunctional regions at 3 weeks after CABG (26 +/- 7%, P < 0.01 vs. before and after ECC values). The magnitude of CV of IB increased even after ECC (3.71 +/- 0.4 dB vs. 7.4 +/- 3.5 dB, P < 0.05), and reached the same level as those in the non-dysfunctional areas. There was a significant relationship between wall thickening at 3 weeks after bypass grafting and magnitude of CV of IB after ECC (r = 0.67, P < 0.05). CONCLUSIONS: Improvement in wall motion was gradually attained after bypass grafting. On the contrary, an increase in the magnitude of CV of IB was obtained immediately after myocardial revascularization. Our data suggest that CV of ultrasonic IB method can provide close real time information regarding the effectiveness of bypass surgery.

Coronary Artery Bypass↗
PubMed1999

Endoscopic variceal ligation is a sufficient procedure for the treatment of oesophageal varices in patients with hepatitis C liver cirrhosis: comparison with injection sclerotherapy.

AIMS: Endoscopic variceal ligation (EVL) is a recently developed alternative to endoscopic injection sclerotherapy (EIS) for the treatment of oesophageal varices. Endoscopic variceal ligation and EIS were compared in an attempt to clarify the efficacy and safety of EVL for patients with cirrhosis due to hepatitis C. METHODS: Endoscopic variceal ligation was performed in 60 patients and EIS in 30. Varices were eradicated in all patients by EVL and 87% (26 out of 30) by EIS. RESULTS: There was no significant difference between EVL and EIS in relation to the incidence of bleeding and the 5 year survival rate after treatment. There were no severe complications except mild substernal pain after EVL, while pulmonary embolism occurred in one patient receiving EIS. CONCLUSIONS: Endoscopic variceal ligation is a safe and effective technique for eradicating oesophageal varices in patients with hepatitis C cirrhosis.

Esophageal and Gastric Varices↗
PubMed1999

Preservation of pathological tissue specimens by freeze-drying for immunohistochemical staining and various molecular biological analyses.

Conditions of preserving DNA, RNA and protein in pathological specimens are of great importance as degradation of such macromolecules would critically affect results of molecular biological analysis. The feasibility of freeze-drying as a means of preserving pathological tissue samples for molecular analysis has previously been shown. In the present study, further tests on long-term storage conditions and analyses of freeze-dried samples by polymerase chain reaction (PCR), reverse transcriptase (RT)-PCR, western blotting and immunohistochemistry are reported. Rat chromosomal DNA of freeze-dried samples stored for 4 years showed slight degradation while RNA degradation was more prominently seen at an earlier stage of storage. However, these 4 year DNA and RNA samples were still able to serve as a template for some PCR and RT-PCR analyses, respectively. Overexpression of c-erbB-2 and p53 protein was demonstrated by western blotting and immunohistochemical staining using freeze-dried human breast cancer tissues. Although macromolecules in freeze-dried samples degrade to some extent during the preservation period, they should still be of value for certain molecular biological analyses and morphological examination; hence, providing more convenient and inexpensive ways of pathological tissue storage.

Animals↗