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Biomedical subjects

S Oka

Publications and source records attributed to S Oka.

At least 325 records · Page 18Linked to original sources

[Growth regulation of vascular cells by cytokines].

Cytokines with stimulatory or inhibitory activities for vascular cells are reviewed. Directly or via humoral factors, vascular endothelial cells interact with blood cells, such as lymphocytes, neutrophils and platelets, while smooth muscle cells do so with inflammatory cells. Various cytokines, including IL-1, 6, 7, 8, GM-, G-, M-CSF, a, b-FGF, PDGF, TGF beta, PAF, PA, PAI-1, cell adhesion molecules and endothelin are produced by endothelial cells and/or smooth muscle cells, and in turn they and cytokines produced by blood cells, act as modulators of growth or function of the vascular cells under some physico-pathological states. Vascular cells, especially, endothelial cells might thus be involved in cytokine network.

Cell Division↗

[Chemotherapy of biliary tract infections (XXXVII). Excretion into bile and gallbladder tissue levels of levofloxacin and its clinical effect in biliary tract infections].

Evaluations were made on biliary excretion and penetration into the gallbladder tissue of levofloxacin (LVFX, DR-3355), a new quinolone antibacterial agent, and its clinical efficacy in biliary tract infections. 1. Gallbladder tissue concentrations and biliary concentrations of LVFX at 2-6 hours at oral administration of 100 mg were 0.58-1.99 micrograms/g and 0.49-5.63 micrograms/ml, respectively. These tissue and biliary levels are almost equal or somewhat higher than the serum levels (0.55-1.63 micrograms/ml) of the compound. 2. The concentrations of LVFX and optical isomer DR-3354 in the serum, gallbladder tissue, and bile were determined after a single or a concomitant administration of LVFX 100 mg and/or ofloxacin (OFLX) 100 to 200 mg. The concentration ratio of LVFX to DR-3354 paralleled with the ratio of the 2 compounds administrated. 3. At a dose of 100 mg, the glucuronide of LVFX in the common duct bile was detected at proportions between 0.9 and 36.0%. 4. A total of 11 patients with biliary tract infections, including 6 cholecystitis 3 cholangitis, and 1 each of cholecystocholangitis and liver abscess was treated with LVFX at 100-200 mg t.i.d. for 3-14 days. Clinical results were excellent or good in 8 cases and fair in 3 cases, resulting in an efficacy rate of 72.7%. 5. A side effect and an abnormal change in laboratory findings were observed in both 1 case each and they were both mild. It was concluded that LVFX showed good penetration to the biliary tract as does OFLX, and that it would be a useful oral agent for the treatment of biliary tract infections.

Adult↗

[A death caused by fulminant B-hepatitis which was latent preoperatively].

It is not always easy to evaluate the preoperative liver functions exactly. In this paper we report a patient who died of fulminant hepatitis postoperatively in spite of careful examination of preoperative liver functions. A 60-year-old male had severe bleeding following total cystectomy, resulting in cardiac arrest. He was resuscitated successfully but developed multiple organ failure. He came through it but thereafter he had repeated infectious episodes from uretero-cutaneous fistula and fluctuation of liver functions. Seven months later he had repair of postoperative ventral hernia. His liver functions were within normal limits except for positive HBs antigen. But eventually the patient died of acute fulminant transfusion hepatitis B 30 days after the operation. A cause of his death was, we presume, loading stress of surgical operation on the acute stage of hepatitis B. Other possible causes or deteriorating factors were drug liver injury, alcoholic chronic hepatitis, and coincidence of non A-non B hepatitis. When HBs antigen is positive in spite of normal liver function test, differential diagnosis between asymptomatic carrier and the first stage of acute hepatitis B should be made carefully.

Cystectomy↗

Human immunodeficiency virus DNA copies as a virologic marker in a clinical trial with beta-interferon.

The number of human immunodeficiency virus (HIV) DNA copies in peripheral blood mononuclear cells (PBMC) was quantitated by the polymerase chain reaction (PCR) and used as a virologic marker in a clinical trial with beta-interferon (beta-IFN) (6 x 10(6) IU/day administered intravenously for 4 weeks). In 11 HIV-infected patients who were clinically stable, the number ranged from 10 to 1,063 copies per 10(5) PBMC. However, percent change of the number in the individual untreated patients stayed between -46.2% and 203.0% of the basal level by one month interval. In six patients who were treated with beta-IFN, changes in the number were not significant before and after the trial.

Biomarkers↗

Further characterization of allergenically active oligosaccharitols isolated from a sea squirt H-antigen.

Complete primary structures of five allergenically active oligosaccharitols (HPG-beta 2-N5a, -N6, -N7a, -N7b, and -N9) derived from a sea squirt H-antigen were studied. Structural characterization was carried out by a new method in which products of limited periodate oxidation, followed by derivatization with p-aminobenzoic acid ethyl ester, were analyzed by a combination of HPLC, fast atom-bombardment mass spectrometry, sequential glycosidase digestion, methylation analysis, and 500-MHz 1H NMR. Established structures of GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3) GlcNAc beta 1-3GalNAc-ol, GalNAc beta 1-4GlcNAc beta 1-3 (GalNAc beta 1-4GlcNAc beta 1-6) GalNAc-ol, GalNAc beta 1-4GlcNAc beta 1-3[GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-6] GalNAc-ol, GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-3[GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-6] GalNAc-ol, and GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3)GlcNAc beta 1-3 [GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3)GlcNAc beta 1-6]GalNAc-ol are represented by HPG-beta 2-N5a, -N6, -N7a, -N7b, and -N9, respectively. These structures have not been encountered previously. Oligosaccharide units GalNAc alpha 1-2Fuc alpha 1-, GalNAc beta 1-4GlcNAc beta 1-, and Fuc alpha 1-3GlcNAc beta 1- are considered to be the allergenically specific epitopes. Partial assignments of 500-MHz 1H NMR spectra of these novel O-linked oligosaccharitols were attempted.

Allergens↗

Primary torsion of the greater omentum.

A case with primary torsion of the greater omentum is reported. This pathological condition is an uncommon cause of acute abdominal emergency and it is very difficult even for general surgeons to differentiate this from other acute abdomen. The etiology remains unknown and the treatment of choice is resection of the affected organ.

Acute Disease↗

Novel proliferative effect of phospholipase A2 in Swiss 3T3 cells via specific binding site.

Phospholipase A2 (PLA2), EC 3.1.1.4, which catalyzes the release of free fatty acids from the sn-2 position of glycerophospholipids, has been extensively studied from the viewpoint of eicosanoid production (Arita, H., Nakano, T., and Hanasaki, K. (1989) Prog. Lipid Res. 28, 273-301). Several lines of evidence suggest that extracellular PLA2 is pathophysiologically related to some disorders, including inflammation and hypersensitivity. Despite this, little is known of the precise mechanism of the pathological processes as well as their intrinsic correlation with dysfunction. Here, we report a novel PLA2 action on the proliferation of Swiss 3T3 fibroblasts via specific binding sites of approximately Mr 200,000. Pancreatic type PLA2 in the active form specifically recognized the sites and stimulated thymidine incorporation in DNA. Its inactive zymogen and other PLA2s from platelets, snake, and bee venoms showed much lesser activities. Although the physiological significance remains to be identified, our finding is the first to offer a new viewpoint on the effect of mammalian extracellular PLA2 on cellular function.

3T3 Cells↗

Inflammatory factors stimulate expression of group II phospholipase A2 in rat cultured astrocytes. Two distinct pathways of the gene expression.

Inflammatory factors such as tumor necrosis factor (TNF), interleukin 1 (IL-1), and lipopolysaccharide (LPS) greatly enhance the expression of group II phospholipase A2 (PLA2-II) mRNA, leading to increased secretion of PLA2-II enzyme from rat-cultured astrocytes. The potent antiinflammatory agent dexamethasone suppressed the PLA2-II expression induced by LPS. In vivo studies also demonstrated that the level of PLA2-II mRNA in the brain increased with intravenous injection of LPS. These results suggest that PLA2-II in the brain plays important roles in the inflammatory response. Agents which increase intracellular cAMP concentration did not stimulate PLA2-II expression by themselves but selectively enhanced TNF-induced PLA2-II expression about 5-fold. Phorbol ester, a well known protein kinase C activator, increased the PLA2-II expression. H-7, a protein kinase C inhibitor, inhibited the LPS-induced PLA2-II expression, but did not inhibit the TNF-induced one. Therefore, we conclude that the TNF-activated pathway differs from the LPS-activated one: the former is enhanced by cAMP and the latter involves protein kinase C.

Animals↗

Effects of various mucosal protective drugs on diethyldithiocarbamate-induced antral ulcer in rats.

This study was designed to determine the effects of exogenous Cu,Zn-superoxide dismutase (SOD) and various mucosal protective agents against antral ulcer induced by diethyldithiocarbamate (DDC), inhibitor of Cu,Zn-SOD. Exogenous Cu,Zn-SOD reduced ulcer formation and prevented a decrease in SOD activity in gastric mucosa. This result indicates that maintenance of mucosal SOD activity is essential to prevent the ulcerogenicity of DDC. Many mucosal protective drugs that increase blood flow, mucus secretion, and endogenous prostaglandin failed to prevent ulcer formation and decrease of mucosal SOD activity. Rebamipide, however, significantly reduced ulcerogenesis and maintained mucosal SOD activity. This suggests that rebamipide has new protective effects on gastric mucosa.

Alanine↗

Immunocytochemical distribution of FMRFamide-like substance in the brain of the cloudy dogfish, Scyliorhinus torazame.

The distribution of the molluscan cardioexcitatory tetrapeptide FMRFamide (Phe-Met-Arg-Phe-NH2) in the brain of the cloudy dogfish, Scyliorhinus torazame, was examined by immunocytochemistry. FMRFamide-like immunoreactivity was demonstrated to occur extensively in various regions of the dogfish brain, except for the corpus cerebelli. Immunoreactive neuronal perikarya were located in the ganglion of the nervus terminalis, the preoptic area, and the hypothalamic periventricular gray matter consisting of the nucleus medius hypothalamicus, the nucleus lateralis tuberis, and the nucleus lobi lateralis. Some of the immunoreactive cells in the hypothalamus were identified as cerebrospinal fluid-contacting neurons. The bulk of the immunostained fibers in the nervus terminalis penetrated into the midventral portion of the telencephalon and ran dorsocaudally toward the basal telencephalon and hypothalamus, showing radial projections or ramifications. The labeled fibers were abundant in the midbasal part of the telencephalon and in the hypothalamus, where some fibers were found in loose networks around the cell bodies of the nucleus septi and hypothalamic periventricular nuclei. The fibers demonstrated in the hypothalamus terminated around the vascular wall of the primary capillary plexus of the median eminence or penetrated deeply into the pars intermedia of the hypophysis. These results suggest that, in the dogfish, an FMRFamide-like substance participates in the regulation of adenohypophysial function. This molecule may have a role as a neurotransmitter and/or neuromodulator in the central nervous system.

Amino Acid Sequence↗

Structures of asparagine-linked oligosaccharides from hen egg-yolk antibody (IgY). Occurrence of unusual glucosylated oligo-mannose type oligosaccharides in a mature glycoprotein.

Asparagine-linked oligosaccharides present on hen egg-yolk immunoglobulin, termed IgY, were liberated from the protein by hydrazinolysis. After N-acetylation, the oligosaccharides were labelled with a UV-absorbing compound, p-aminobenzoic acid ethyl ester (ABEE). The ABEE-derivatized oligosaccharides were fractionated by anion exchange, normal phase and reversed phase HPLC, and their structures were determined by a combination of sugar composition analysis, methylation analysis, negative ion FAB-MS, 500 MHz 1H-NMR and sequential exoglycosidase digestions. IgY contained monoglucosylated oligomannose type oligosaccharides with structures of Glc alpha 1-3Man7-9-GlcNAc-GlcNAc, oligomannose type oligosaccharides with the size range of Man5-9GlcNAc-GlcNAc, and biantennary complex type oligosaccharides with core region structure of Man alpha 1-6(+/- GlcNAc beta 1-4)(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(+/- Fuc alpha 1-6)GlcNAc. The glucosylated oligosaccharides, Glc1Man8GlcNAc2 and Glc1Man7GlcNAc2, have not previously been reported in mature glycoproteins from any source.

4-Aminobenzoic Acid↗

Macrophage-activating factor extracted from mycoplasmas.

Mycoplasmas (M. gallisepticum, chicken mycoplasmas), in concert with interferon gamma (IFN gamma), were effective in activating macrophages (M theta) to be tumoricidal. The M theta-activating capacity of mycoplasmas was maintained after treatment with heat. 0.1 M NaOH, 1 M HCl, or trypsin. M theta-activating factor was extracted from mycoplasmas with chloroform/methanol and water (Mf-B). Mf-B was also effective in activating M theta in the presence of IFN gamma. The threshold dose of Mf-B for M theta of ordinary C3H/He mice and that for those of C3H/HeJ mice, the latter being known to be low responders to bacterial lipopolysaccharide, were actually the same. This seems to indicate that the effectiveness of Mf-B was not attributable to possibly contaminating lipopolysaccharides, and that the pathway of activity of Mf-B is different from that of lipopolysaccharides. Since the M theta-activating principle was only a very small part of Mf-B, we have not yet succeeded in identifying it, but there was no evidence that it was protein, nucleic acid, sugar, or lipid. The cytotoxicity of M theta activated by Mf-B plus IFN gamma was dependent on L-arginine in the culture, suggesting that arginine metabolites are involved in M theta cytotoxicity. Mf-B induced a small amount of tumor necrosis factor in M theta, and this induction was markedly enhanced by IFN gamma.

Animals↗

Intra-abdominal desmoid tumors in familial polyposis coli: a case report of tumor regression by prednisolone therapy.

A case of intra-abdominal desmoid tumors in familial polyposis coli (FPC), which regressed and disappeared by prednisolone treatment, is reported. A 37-year-old Japanese man with abdominal lumps was admitted to our hospital. He had had proctocolectomy two years before because of FPC with rectal cancer. At laparotomy, tumors were present in the abdominal wall, mesentery, and retroperitoneum. Only a small part of the tumors was resected and diagnosed microscopically to be desmoid tumors. With prednisolone administration (20 to 5 mg/day) subjective symptoms were ameliorated and desmoid tumors slowly regressed. Bilateral hydronephrosis continued and resulted in "retroperitoneal fibrosis." To our knowledge, this case is the first well-documented case of retroperitoneal fibrosis in a patient with FPC. The characteristics of the desmoid tumor in familial polyposis coli or in Gardner's syndrome and the methods for its management are discussed.

Abdominal Neoplasms↗

Immunoglobulin superfamily molecules in the nervous system.

Among the various types of membrane molecules involved in cell-cell interactions in the nervous system, we have focused in this review upon membrane proteins belonging to the immunoglobulin superfamily (IgSF). IgSF molecules are distinctive in that: (1) a large percentage of known neural adhesion molecules belongs to the IgSF; (2) they are homologous in structure (Ig domain), yet exhibit large variation of function in cell-cell interactions. The structure of IgSF molecules is briefly summarized in Section II, and each member of the IgSF which has been found in the nervous system is reviewed in Section III. In Section IV, we have discussed possible properties of yet-unknown nervous system IgSF molecules, on the assumption that nervous system IgSF molecules thus far discovered comprise only a small portion of those existing. Discussion is based upon an analogy with the immune system and upon knowledge of cell-cell interactions in the development of the nervous system. Our principal aims in this review are to summarize knowledge of neural IgSF molecules and to discuss the possibility that some IgSF molecules may encode in their structures instructions for recognizing, or for being recognized by, target neural cells. Further growth of knowledge of IgSF molecules may yield insights into the patterns of cell-cell interactions underlying the formation of neuronal circuits during development.

Animals↗

Ultrastructural localization of telencephalin, a telencephalon-specific membrane glycoprotein, in rabbit olfactory bulb.

Localization of a telencephalon-specific glycoprotein, telencephalin (TCLN), in the olfactory bulb of the rabbit was studied with an electron microscope. Anti-TCLN antisera appeared to stain plasma membrane, Golgi apparatus and multivesicular bodies of granule cells which are local circuit interneurons in the bulb. Principal neurons, mitral and tufted cells, were not immunoreactive. No glial cells showed immunoreactivity. Thus, expression of telencephalin is specific not only to the telencephalic segment of the brain, but also to the neuronal types.

Animals↗