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Biomedical subjects

H Sano

Publications and source records attributed to H Sano.

At least 307 records · Page 17Linked to original sources

Myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies -- related scleroderma renal crisis treated with double-filtration plasmapheresis.

A 46-year-old female patient who was diagnosed with systemic sclerosis (SSc) developed rapidly progressive renal failure without elevation of blood pressure or plasma renin concentration. Renal biopsy revealed necrotizing crescentic glomerulonephritis (pauci-immune type) and the myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA) titer was found to be elevated to 669 EU/ml. Methylprednisolone (MP) pulse therapy followed by prednisolone (PSL) and mizoribine (MZR) did not suppress the progression of renal failure. Therefore, we started double-filtration plasmapheresis (DFPP) which effectively removed MPO-ANCA and prevented renal failure despite the relatively low dose of immunosuppressive agents.

Acute Kidney Injury↗

Extrahepatic portosystemic venous shunt without portal hypertension.

A 72-year-old woman was admitted for recurrent episodes of encephalopathy. Laboratory data showed mild liver dysfunction and hyperammonemia, while she had neither anemia nor splenomegaly. The dilated inferior mesenteric vein (IMV) was opacified retrogradely from the superior mesenteric vein by superior mesenteric arteriography, and IMV was found to connect with the inferior vena cava (IVC) through a torturous shunt. No obstruction of the extrahepatic portal vein or hepatic vein was observed by arteriography. Histological evaluation of the liver biopsy indicated remarkable fatty change without cirrhosis. Finally, we diagnosed this case as extrahepatic portosystemic venous shunt without portal hypertension.

Aged↗

The receptor for advanced glycation end products mediates the chemotaxis of rabbit smooth muscle cells.

Long-term incubation of proteins with glucose leads to advanced glycation end products (AGEs) with fluorescence and a brown color. We recently demonstrated immunologically the intracellular AGE accumulation in smooth muscle cell (SMC)-derived foam cells in advanced atherosclerotic lesions. To understand the mechanism of AGE accumulation in these foam cells, we have now characterized the interaction of AGE proteins with rabbit-cultured arterial SMCs. In experiments at 4 degrees C, 125I-labeled AGE-bovine serum albumin (AGE-BSA) showed a dose-dependent saturable binding to SMCs with an apparent dissociation constant (Kd) of 4.0 microg/ml. In experiments at 37 degrees C, AGE-BSA underwent receptor-mediated endocytosis and subsequent lysosomal degradation. The endocytic uptake of 125I-AGE-BSA was effectively inhibited by unlabeled AGE proteins such as AGE-BSA and AGE-hemoglobin, but not by acetylated LDL and oxidized LDL, well-known ligands for the macrophage scavenger receptor (MSR). Moreover, the binding of 125I-AGE-BSA to SMCs was affected neither by amphoterin, a ligand for one type of the AGE receptor, named RAGE, nor by 2-(2-furoyl)-4(5)-(2-furanyl)-1H-imidazole-hexanoic acid-BSA, a ligand for the other AGE receptors, p60 and p90. This indicates that the endocytic uptake of AGE proteins by SMCs is mediated by an AGE receptor distinct from MSR, RAGE, p60, and p90. To examine the functional role of this AGE receptor, the migratory effects of AGE-BSA on these SMCs were tested. Incubation with 1-50 microg/ml of AGE-BSA for 14 h resulted in significant dose-dependent cell migration. The AGE-BSA-induced SMC migration was chemotactic in nature and was significantly inhibited (approximately 80%) by an antibody against transforming growth factor-beta (TGF-beta), and the amount of TGF-beta secreted into the culture medium from SMC by AGE-BSA was sevenfold higher than that of control, indicating that TGF-beta is involved in the AGE-induced SMC chemotaxis. These data suggest that AGE may play a role in SMC migration in advanced atherosclerotic lesions.

Animals↗

New anticancer antibiotics pelagiomicins, produced by a new marine bacterium Pelagiobacter variabilis.

In the course of our screening for new anticancer compounds produced by marine bacteria, we found that a new genus marine bacterium Pelagiobacter variabilis produced new phenazine antibiotics, pelagiomicins A, B and C. Those compounds were labile in water and alcohols. The absolute structure of the main component, pelagiomicin A, and the structures of the minor ones were determined from the spectroscopic data and by synthesis. Pelagiomicin A exhibits activity against Gram-positive and -negative bacteria and antitumor activity in vitro and in vivo.

Antibiotics, Antineoplastic↗

Hydroxyakalone, a novel xanthine oxidase inhibitor produced by a marine bacterium, Agrobacterium aurantiacum.

A new xanthine oxidase inhibitor named hydroxyakalone was isolated from the culture broth of a marine bacterium Agrobacterium aurantiacum N-81106. Structure of hydroxyakalone was determined to be 4-amino-1H-pyrazolo[3,4-d]pyrimidine-3-one-6-ol by the spectral studies of hydroxyakalone and its permethyl derivative. The concentration to induce 50% inhibition (IC50) was 4.6 microM against xanthine oxidase.

Enzyme Inhibitors↗

Korormicin, a novel antibiotic specifically active against marine gram-negative bacteria, produced by a marine bacterium.

A novel antibiotic named korormicin was isolated from the marine bacterium, Pseudoalteromonas sp. F-420. This strain was isolated from the surface of a macro alga Halimeda sp. collected from Palau (the Republic of Belau). The planar structure of korormicin was determined by the result of 2D NMR studies and mass spectral data. Korormicin had specific inhibitory activity against marine Gram-negative bacteria, but was inactive against terrestrial microorganisms.

Anti-Bacterial Agents↗

Pitfalls in aneurysm surgery in acute stages.

Since the dawn of aneurysm surgery, many aneurysms present a more complex challenge. Large size, intimacy with critical perforator branches, deep location, atherosclerotic walls, ruptured aneurysms in the elderly and incorporation of afferent or efferent arteries in the dome represent factors that singly or in combination preclude safe clipping while high pressure circulation continues in the aneurysm. Despite the relative frequency of many class of aneurysms, there remains in the neurosurgical community some degree of confusion regarding the detailed anatomic features and the technical aspects of the treatment of these lesions in the acute stage. In our study of 1,433 cases, we have enumerated four aspects of the pitfalls in aneurysm surgery which should be considered when planning the operative approach to these lesions. These four aspects will be reviewed in relation to the aneurysm surgery: (1) inadequate pre-operative planning; (2) inappropriate response to unexpected premature rupture; (3) poor clipping techniques and clip selection; (4) unintentional occlusion or injury of perforating branches. This discussion will simply elaborate our own conceptual and microsurgical technical approach in dissecting the aneurysms. Minimal retraction was used during the whole surgical procedure. The intracranial brain tension was reduced through a ventricular tap for hydrocephalus or evacuation of hematoma prior to aneurysm surgery. A venous pathway was established for blood circulation. Sharp dissection, using our newly designed jet irrigation bipolar suction method was employed. Regarding the clipping of the aneurysm, we used the tentative clipping and the dome coagulation method thereby preventing the ischemic changes and shortening of the entire clipping procedure. Although the strategies, discussed represent simply our approach to this problem, the principles included have proven quite successful and have allowed safe and definitive treatment in the overwhelming majority of patients and also options to overcome the pitfalls in aneurysm surgery.

Acute Disease↗

Expression of adhesion molecules on mononuclear cells from individuals with stable atopic asthma.

Activated mononuclear cells (lymphocytes and monocytes) (MNCs) circulate in peripheral blood and accumulate in the airways of individuals with steady-state asthma. The expression of adhesion molecules on MNCs of 10 patients with steady-state atopic asthma and 10 non-atopic control subjects was measured by flow cytometry. The mean fluorescence intensity of CD23 (P = 0.0003), CD11a (P = 0.034), and very late antigen-4 (VLA-4) (P = 0.016) was increased on lymphocytes of asthmatic patients relative to those of controls. Although the expression of CD16 (P = 0.002) and CD23 (P = 0.002), which are associated with differentiation into macrophages, was increased on monocytes of patients relative to those of controls, monocyte expression of VLA-4 (P = 0.006) and sialyl Lewis x (P = 0.005) was reduced. The concentration of interleukin-4 (IL-4) in serum was significantly higher in asthmatic patients than in normal subjects (P = 0.023), and a significant correlation was apparent between the serum concentration of IL-4 and the expression of VLA-4 on lymphocytes (p = 0.71, P = 0.03) or on monocytes (p = -0.72, P = 0.03) in asthmatic patients. Results suggest that IL-4 may contribute to the priming of adhesion molecule expression on lymphocytes even in steady-state conditions in individuals with chronic allergic inflammation.

Adolescent↗

[AGE receptor].

Explore the source record for details and available documents.

Animals↗

Identification of significant residues in the substrate binding site of Bacillus stearothermophilus farnesyl diphosphate synthase.

Farnesyl diphosphate synthases have been shown to possess seven highly conserved regions (I-VII) in their amino acid sequences [Koyama et al. (1993) J. Biochem. (Tokyo) 113, 355-363]. Site-directed mutants of farnesyl diphosphate synthase from Bacillus stearothermophilus were made to evaluate the roles of the conserved aspartic acids in region VI and lysines in regions I, V, and VI. The aspartate at position 224 was changed to alanine or glutamate (mutants designated as D224A and D224E, respectively); aspartates at positions 225 and 228 were changed to isoleucine and alanine (D225I, D228A); lysine at position 238 was changed to either alanine or arginine (K238A, K238R). The lysines at positions 47 and 183 were changed to isoleucine and alanine (K471, K183A), respectively. Kinetic analyses of the wild-type and mutant enzymes indicated that the mutagenesis of Asp-224 and Asp-225 resulted in a decrease of Kcat values of approximately 10(4)- to 10(5)-fold compared to the wild type. On the other hand, D228A showed a Kcat value approximately one-tenth of that of the wild type, and the k(m) value for isopentenyl diphosphate increased approximately 10-fold. Both K471 and K183A showed k(m) values for isopentenyl diphosphate 20-fold larger and kcat values 70-fold smaller than the wild type. These results suggest that the two conserved lysines in regions I and V contribute to the binding of isopentenyl diphosphate and that the first and the second aspartates in region VI are involved in catalytic function. Aspartate-228 is also important for the binding of isopentenyl diphosphate rather than for catalytic reaction.

Acyclic Monoterpenes↗

N (epsilon)-(carboxymethyl)lysine protein adduct is a major immunological epitope in proteins modified with advanced glycation end products of the Maillard reaction.

Long-term incubation of proteins with glucose leads to the formation of advanced glycation end products (AGE). Recent immunological studies have suggested the potential role of AGE in atherosclerosis, aging, and diabetic complications. We previously prepared a monoclonal (6D12) as well as a polyclonal anti-AGE antibody and proposed the presence of a common AGE structure(s) that may act as a major immunochemical epitope [Horiuchi, S., Araki, N., & Morino, Y. (1991) J. Biol. Chem. 266, 7329-7332]. The purpose of the present study was to determine the major epitope. Amino acid analysis of AGE-proteins indicated that N(epsilon)-(carboxymethyl)lysine (CML) was a major modified lysine residue. Immunologic studies demonstrated the positive reaction of 6D12 not only to all CML-modified proteins tested, but also to BSA modified with several aldehydes known to generate a CML-protein adduct, and a linear correlation between the CML contents of CML-BSA and their immunoreactivity to 6D12 up to approximately 8 mol/mol of protein. Further experiments with CML analogs revealed that the epitope of 6D12 is a CML-protein adduct with an important carbonyl group. In contrast to 6D12, our polyclonal anti-AGE antibody showed a significant but much weaker immunoreactivity to CML-BSA, suggesting that the polyclonal antibody contains two populations, one reactive to CML (CML-PA) and the other unreactive to CML (Non-CML-PA). Non-CML-PA separated from CML-PA by CML-BSA affinity chromatography did not react with all CML-modified preparations, but retained its property to react commonly with AGE preparations obtained from proteins, lysine derivatives, and monoaminocarboxylic acids. Therefore, it is clear that a CML-protein adduct is a major immunological epitope in AGE structures, but there still exist other major epitope(s) expressed commonly in AGE-proteins.

Animals↗

Body surface distribution of significant changes in QRST time-integral values after radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome.

We analyzed 87-lead body surface QRST time-integral values (QRST values) in 29 patients with Wolff-Parkinson-White syndrome (group A, 17 patients with manifest left-sided accessory pathway; group B, 6 patients with manifest right-sided accessory pathway; and group C, 6 patients with concealed left-sided accessory pathway), before, 1 day after, and 1 week after radiofrequency catheter ablation (RCA). The number of leads with abnormal QRST values was significantly lower 1 week after RCA compared with those before RCA and 1 day after RCA in groups A and B (p < 0.05); there was no significant difference in QRST values before and 1 day after RCA in groups A and B. The QRST values over areas with preexisting repolarization abnormalities were significantly altered 1 week after RCA compared with before and 1 day after RCA in groups A and B (p < 0.01). However, there was no significant difference in the QRST values over areas without preexisting abnormalities before RCA. In group C, there were no significant differences in the QRST values or the number of leads with abnormal QRST values before, 1 day and 1 week after RCA. In conclusion, RCA did not significantly influence repolarization properties over areas without preexisting abnormalities, but gradually reduced preexisting repolarization abnormalities, which were closely related to the location of the accessory pathway in patients with manifest Wolff-Parkinson-White syndrome. Our results suggest that body surface QRST values are useful for assessment of repolarization abnormalities during the periablation period.

Adolescent↗