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Biomedical subjects

Y Okamoto

Publications and source records attributed to Y Okamoto.

At least 73 records · Page 4Linked to original sources
PubMed2001

Interleukin-4 reversed the Interleukin-1-inhibited proteoglycan synthesis through the inhibition of NO release: a possible involvement of intracellular calcium ion.

Interleukin-1 (IL-1) causes cartilage degradation through nitric oxide (NO) synthesis. Although Interleukin-4 (IL-4) antagonizes the IL-1-mediated cartilage degradation, the precise mechanisms are not clear. We examined the effect of IL-4 on NO synthesis in parallel with intracellular Ca levels ([Ca(2+)]i) and proteoglycan (PG) synthesis. IL-4-inhibited IL-1-enhanced NO release in a dose-dependent manner. IL-1-enhanced [Ca(2+)]i in the chondrocytes, and IL-4 attenuated this increase. IL-4 reversed IL-1-inhibited PG synthesis. Accordingly, IL-4 reversed the IL-1-inhibited PG synthesis through the inhibition of NO release. An increase in [Ca(2+)]i with IL-1 is possibly involved in this action.

Journal Article↗
PubMed2001

Iantherans A and B, unique dimeric polybrominated benzofurans as Na,K-ATPase inhibitors from a marine sponge, Ianthella sp.

Two novel tetrabrominated benzofuran derivatives, named iantherans A and B, were isolated from an Australian marine sponge of the genus lanthella. The unique structures comprised of 2,3-bis(sulfooxy)-1,3-butadiene and two brominated benzofuran moieties were determined by spectroscopic and chemical methods. Iantheran A has a (Z,Z)-1,3-butadiene moiety, whereas iantheran B is the geometric isomer possessing a (Z,E)-1,3-butadiene moiety. The inhibitory activities of the iantherans and their derivatives against Na,K-ATPase as well as the efficacy of iantheran A against other several enzymes were evaluated.

Animals↗
PubMed2001

Laparoscopic-assisted removal of a large urachal cyst.

A 48-year-old woman was seen because of an abdominal tumor. Laparoscopy was performed for diagnosis and treatment. A large cystic mass was hanging from the anterior abdominal wall and was removed with laparoscopic assistance. Histologic examination revealed a urachal cyst. (J Am Assoc Gynecol Laparosc 8(1):159-160, 2001)

Female↗
PubMed2001

Laparoscopic-assisted surgery for benign ovarian cyst in a young girl.

A 7-year-old girl was admitted to our hospital because of sudden lower abdominal pain and vomiting. Emergency laparoscopy and cystectomy were performed, with a diagnosis of torsion of an ovarian cyst. All manipulations were possible through a 2-cm incision in the abdominal wall.

Abdominal Pain↗
PubMed2001

Biological activities of carbohydrate-branched chitosan derivatives.

Two types of biological activities of the carbohydrate-branched chitosan derivatives were investigated. One is the specific interaction with lectins and bacterium. The other is activation of canine polymorphonuclear leukocyte (PMN) cells. The specific bindings of the L-fucose-branched chitosan derivative with Ulex europaeus agglutinin I (UEA-I) and the N-acetyl-D-glucosamine-branched chitosan derivative with Concanavalin A (Con A) were confirmed by a surface plasmon resonance technique. The specific aggregation of the fluorescence-labeled L-fucose-branched chitosan derivative with Pseudomonas aeruginosa was observed by fluorescent microscopic observation. The aggregation would be attributed to the specific binding between the L-fucose-branched chitosan derivative and PA-II receptor on the cell surface of P. aeruginosa. The influence of the chitosan derivatives on the active oxygen species generation from canine PMN cells was also investigated by the luminol-aided chemiluminescence method. The chemiluminescence responses depended on the degree of substitution and water solubility of the chitosan derivatives. The water-insoluble chitosan derivatives would stimulate the PMN cells by a phagocytosis mechanism, and the water-soluble ones would sensitize the PMN cells by a priming mechanism.

Animals↗
PubMed2001

Suppressive effect of locally produced interleukin-10 on respiratory syncytial virus infection.

Interleukin (IL)-10 is known to be a multifunctional cytokine. This study was designed to evaluate the role of IL-10 during respiratory syncytial virus (RSV) infection using a C57BL/6 transgenic (TG) mouse model in which the expression of murine IL-10 cDNA was regulated by a human salivary amylase promoter (IL-10 TG mice). These mice expressed a large amount of IL-10 in the nasal mucosa and in salivary glands. Viral replication in the respiratory tract after intranasal infection with RSV was suppressed significantly in IL-10 TG mice compared to non-transgenic controls. This suppression was IL-10 specific, because it was prevented by treating mice with neutralizing anti-IL-10 antibodies. We also found that IL-10-stimulated T cells displayed cytotoxic activity against infected murine nasal epithelial cells. Previous data indicated that IL-10 induces Fas ligand (L) expression on mouse T cells. Taken together, these data suggest that Fas/Fas L mediated cytotoxicity is involved in the suppression of RSV replication observed in IL-10 TG mice after intranasal infection.

Animals↗
PubMed2001

One-bone forearm formation using vascularized fibula graft for massive bone defect of the forearm with infection: case report.

Massive long-bone defects of greater than 6 cm are difficult to treat with conventional bone grafts, and other methods are sometimes recommended, such as vascularized bone grafts or bone transport using the Ilizarov external fixator. The combination of local infection with a massive bone defect exacerbates the problem, and provides an even more negative prognosis. The authors treated a large bone defect of the forearm with local infection, using a one-bone forearm formation with a large vascularized fibula graft. They attached an adequate amount of muscle fascia to the vascularized fibula, which was useful not only for coverage of the skin defect, but also for treatment of the local infection. Twenty months after surgery, elbow and hand functions were maintained, and the patient had no disturbance of hand function in daily activities, although rotation of the forearm was sacrificed.

Bone Wires↗
PubMed2001

Intraarterial infusion chemotherapy and radiotherapy with or without surgery for patients with locally advanced or recurrent breast cancer.

We analyzed response, side effects, and local control rates of a multimodal treatment consisting of intraarterial infusion chemotherapy (IAIC) and radiotherapy with or without surgery for patients with locally advanced or recurred breast cancer. Thirty-three patients, clinically diagnosed as stage IIB in 1, IIIA in 2, IIIB in 12, IV in 18, were treated from 1991 to 1998. Twenty-five were primary and eight were recurrent cases after surgery. IAIC started as initial treatment up to three times maximum. In most cases, doxorubicin 50 mg, cisplatin 50 mg, and mitomycin 10 mg were infused in the subclavian and/or internal mammary artery. After IAIC, patients in primary cases underwent radical mastectomy or breast conservation surgery, after radiotherapy at a total dose of 50 Gy/25 fractions/5 weeks with a boost of 10 Gy. In recurrent cases, a full dose of radiotherapy was delivered. Clinical objective and complete response rates were 78% and 9% after IAIC. Despite a high rate of residual positive margin (67%) or clinically residual carcinoma, local recurrence developed only in 2 patients (6%) and local control rates at 5 years were calculated as 89%. Bone marrow suppression was frequent, and skin vesiculation (15%) and ulceration (9%) were experienced after IAIC. Skin ulcer (6%), brachial plexus neuropathy (3%), and radiation pneumonitis (3%) occurred as late toxicity. IAIC was effective as an induction treatment and radiotherapy played a role of local control for patients with locally advanced or recurrent breast cancer.

Adult↗
PubMed2001

Validity of local treatment including intraarterial infusion chemotherapy and radiotherapy for fungating adenocarcinoma of the breast: case report of more than 8-year survival.

A 39-year-old woman came to us complaining of severe anemia (hemoglobin: 2.3 g/dl) and a painful right breast that was entirely occupied by an ulcerative, foul-smelling tumor approximately 20 cm in maximum dimension. The tumor, which was determined to be mucinous adenocarcinoma at biopsy, had invaded the chest wall with multiple lung metastases (T4cN2M1 stage IV). After a blood transfusion, the patient received the following multimodal treatment: concurrent chemoradiotherapy (50 Gy), intraarterial infusion chemotherapy consisting of doxorubicin 50 mg, mitomycin-C 10 mg, and cisplatin 50 mg, and skin graft surgery. After intraarterial infusion chemotherapy, the fungating tumor disappeared. The patient experienced a relapse of right pleural effusion 2 years later and received multimodal treatment. Now, March 30, 2000, the patient is doing well without local recurrence, 8 years after her first admission. The combination of intraarterial infusion chemotherapy and radiotherapy plays a role in successful treatment of extensive local disease of the breast.

Adenocarcinoma, Mucinous↗
PubMed2001

Ca(2+) channels activated by endothelin-1 in CHO cells expressing endothelin-A or endothelin-B receptors.

We compared the Ca(2+) channels activated by endothelin-1 (ET-1) in Chinese hamster ovary (CHO) cells stably expressing endothelin type A (ET(A)) or endothelin type B (ET(B)) receptors using the Ca(2+) channel blockers LOE-908 and SK&F-96365. In both CHO-ET(A) and CHO-ET(B), ET-1 at 0.1 nM activated the Ca(2+)-permeable nonselective cation channel-1 (NSCC-1), which was sensitive to LOE-908 and resistant to SK&F-96365. ET-1 at 1 nM activated NSCC-2 in addition to NSCC-1; NSCC-2 was sensitive to both LOE-908 and SK&F-96365. ET-1 at 10 nM activated the same channels as 1 nM ET-1 in both cell types, but in CHO-ET(A), it additionally activated the store-operated Ca(2+) channel (SOCC), which was resistant to LOE-908 and sensitive to SK&F-96365. Up to 1 nM ET-1, the level of the formation of inositol phosphates (IPs) was low and similar in both cell types, but, at 10 nM ET-1, it was far greater in CHO-ET(A) than in CHO-ET(B). These results show that, in CHO-ET(A) and CHO-ET(B), ET-1 up to 10 nM activated the same Ca(2+) entry channels: 0.1 nM ET-1 activated NSCC-1, and ET-1 > or = 1 nM activated NSCC-1 and NSCC-2. Notably, in CHO-ET(A), 10 nM ET-1 activated SOCCs because of the higher formation of IPs.

Acetamides↗
PubMed2001

Pulmonary reduction of an intravascular redox polymer.

Pulmonary endothelial cells in culture reduce external electron acceptors via transplasma membrane electron transport (TPMET). In studying endothelial TPMET in intact lungs, it is difficult to exclude intracellular reduction and reducing agents released by the lung. Therefore, we evaluated the role of endothelial TPMET in the reduction of a cell-impermeant redox polymer, toluidine blue O polyacrylamide (TBOP(+)), in intact rat lungs. When added to the perfusate recirculating through the lungs, the venous effluent TBOP(+) concentration decreased to an equilibrium level reflecting TBOP(+) reduction and autooxidation of its reduced (TBOPH) form. Adding superoxide dismutase (SOD) to the perfusate increased the equilibrium TBOP(+) concentration. Kinetic analysis indicated that the SOD effect could be attributed to elimination of the superoxide product of TBOPH autooxidation rather than of superoxide released by the lungs, and experiments with lung-conditioned perfusate excluded release of other TBOP(+) reductants in sufficient quantities to cause significant TBOP(+) reduction. Thus the results indicate that TBOP(+) reduction is via TPMET and support the utility of TBOP(+) and the kinetic model for investigating TPMET mechanisms and their adaptations to physiological and pathophysiological stresses in the intact lung.

Acrylic Resins↗
PubMed2001

Anti-inflammatory effects of 5-aminosalicylic acid conjugates with chenodeoxycholic acid and ursodeoxycholic acid on carrageenan-induced colitis in guinea-pigs.

Two epimeric bile acid conjugates, 5-aminosalicylic acid-chenodeoxycholic acid (5-ASA-CDCA) and 5-aminosalicylic acid-ursodeoxycholic acid (5-ASA-UDCA), were synthesized to deliver 5-ASA to the large intestine by oral administration. The movement of the conjugates down the gastrointestinal tract and the anti-inflammatory effects on ulcerative colitis were investigated by administering the conjugates to guinea-pigs with an inflammatory bowel disease induced by 2% degraded carrageenan solution. The conjugates were protected from deconjugation in stomach and small intestine and reached the caecum and the colon, where 5-ASA was more easily liberated from 5-ASA-CDCA than from 5-ASA-UDCA. The conjugates at doses equivalent to 50 or 150 mg kg(-1) 5-ASA were orally administered once a day for 4 weeks from the 15th day after starting carrageenan treatment. The body weights and the bleeding scores of occult blood in faeces were measured during the experiment. The number of ulcers in the caecum and the colon were counted after killing the guinea-pigs at the end of the experiment. Rapid onset of efficacy was shown by a significant reduction in bleeding scores within a week after administration of the conjugates. Treatment with the lower dose of 5-ASA-CDCA showed a recovery of body weight and a significantly decreased number of ulcers in the caecum, and the ulcers in the colon had completely disappeared bythe end of the experiment. There was a good correlation found between the number of ulcers in the caecum and the bleeding scores of occult blood in faeces. The findings indicate that both conjugates were sufficiently delivered to the large intestine without deconjugation and that the lower dose of 5-ASA-CDCA is enough for treatment of ulcerative colitis in colonic inflammatory bowel diseases.

Animals↗
PubMed2001

[Cytokine balance in the pathogenesis of rheumatoid arthritis].

Rheumatoid arthritis (RA) is a common, frequently severe, chronic inflammatory disease. Although the cause of RA remains unknown, recent advances in understanding its pathogenesis have been substantial. Despite the use of a variety of medications, the treatment of RA is not fully effective in most patients. A T-helper type 1 (Th1)/T-helper type 2 (Th2) cytokine imbalance has been suggested to be of pathogenic importance in several diseases. In this review, the information of cytokine balance in both the experimental model of arthritis and patients with arthritis were summarized. Furthermore, to characterize the cytokine balance at a single cell level, we analyzed the subtypes of cytokine-secreting cells in an experimental model of arthritis using a dual color enzyme-linked immunospot assay (Stardust assay) which we newly developed. These information including our findings might provide us the clue for diagnosis and therapy of arthritis.

Animals↗
PubMed2001

Left ventricular epicardial outflow tract tachycardia: a new distinct subgroup of outflow tract tachycardia.

The present study investigated the incidence and ECG characteristics of ventricular tachycardias (VTs) originating from the left ventricular (LV) epicardium. Thirty-one consecutive patients with VT or premature ventricular contraction originating from the outflow tract (OT-VT) underwent catheter ablation. Twenty-one OT-VTs were ablated from the endocardium in the right ventricular (RV) OT and 3 were ablated from the endocardium in the LVOT. In the remaining 7 patients, 4 (13%) OT-VTs were LV epicardial in origin, and 1 of these was ablated from the left sinus of Valsalva. The ECG characteristics of OT-VT of epicardial origin included prominent tall R-waves in the inferior leads, an R-wave in V1 and an S-wave in V2, precordial R-wave transition in V2-4, a deep QS-wave in aVL, and no S-wave in V6. In addition, there was an atypical left bundle branch block morphology with an inferior axis. These findings were observed during pacing from several sites in the LV epicardium. Furthermore, pacing from the left sinus of Valsalva caused a relatively tall R in V1, deep S-wave in V2 and a tall R-wave with a shallow S-wave in V3, as well as tall R-waves in the inferior leads, which represented intermediate characteristics between RV endocardial OT-VT and LV endocardial OT-VT. In conclusion, OT-VT originating from the LV epicardium is not uncommon and has characteristic ECG findings. Some of them can be ablated from the left sinus of Valsalva.

Adult↗