Search PubMed⌕ Search

Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 307 records · Page 17Linked to original sources
PubMed1995

Intravascular ultrasound imaging of peripheral arteries as an adjunct to atherectomy: preliminary experience.

12 atherosclerotic lesions in nine patients, including four restenoses after balloon angioplasty, were treated by atherectomy under the guidance of intravascular ultrasound (US). Echogenicities of the plaques and morphological alterations in the arterial walls produced by atherectomy were evaluated. The two-layered appearance of post-angioplasty restenoses was found to be inner fibrous intimal thickening with proliferation of smooth muscle cells and outer residual collagen-rich plaque. The deep cut surfaces were shown as concave U-shaped defects. Medial tissues were present in all cases where intravascular US demonstrated the disruption of a thin hyperechoic layer of the internal elastic lamina. Intravascular US imaging may provide valuable information on the degree, eccentricity and histological type of stenosis, the presence of calcification before atherectomy, and on the extent of excision and the morphological changes in the arterial wall after atherectomy.

Aged↗
PubMed1995

Formation of lyso-glycosphingolipids by Streptomyces sp.

The actinomycete strain Streptomyces sp. H37 produces a novel glycosphingolipid-degrading enzyme. This strain was capable of converting ganglioside GM1 to lyso-GM1. After cultivation for 5 days in medium containing GM1, peptone, and detergent, GM1 was found to be almost completely converted to lyso-GM1. The product was purified on a DEAE-Sephadex A-25 column and thin layer chromatographies. The purified lyso-GM1 was hydrolyzed by endoglycoceramidase, and the released oligosaccharide moiety was identified as that of GM1 by HPLC using the pyridylaminoderivative method. The counterpart sphingosine moiety was confirmed with TLC. Moreover, the structure of lyso-GM1 was ascertained by 1H-NMR analysis. The maximum formation of lyso-GM1 was found in 50 mM potassium phosphate buffer (pH 7.5) containing 0.1% glycodeoxycholate. Various lyso-glycoshingolipids, including those of ganglio-, neolacto-, and globo-types, were formed from their parent glycosphingolipids using this strain.

Chromatography, High Pressure Liquid↗
PubMed1995

Superselective intraarterial infusion of cisplatin for squamous cell carcinoma of the mouth: preliminary clinical experience.

OBJECTIVE: The purpose of this study was to assess the initial clinical response to superselective intraarterial infusion of cisplatin for treating stage III and stage IV squamous cell carcinoma of the mouth. SUBJECTS AND METHODS: Thirteen patients received intraarterial cisplatin therapy. The tumors were located in the tongue (n = 7), gingiva (n = 3), buccal mucosa (n = 1), hard palate (n = 1), and floor of the mouth (n = 1). A coaxial technique was used to place microcatheters in the lingual, facial, inferior alveolar, buccinator, and distal internal maxillary arteries, depending on tumor location. The feeding vessels were identified by staining the tumor with infusion of indigocarmine dye in the selected vessel. Relatively low-dose cisplatin (30-40 mg/m2) was injected at the rate of 50 mg/hr. Two or three injections were performed, with a 1-week interval between injections. After chemotherapy, eight patients underwent surgery, four had radiation therapy, and one had both. RESULTS: Thirty-four intraarterial infusions were done successfully without any complications. Arterial infusion of indigocarmine dye was useful for exact identification of feeding vessels, especially when the tumor was extensive, at the margin of the arterial supply, or near the midline. The overall response rate was 92% (complete response [tumor completely resolved], 38%; partial response [tumor reduction > or = 50%], 54%). Ten of 13 patients had no recurrence from 4 to 19 months (mean, 10 months) after treatment. Two patients died of metastatic diseases 6 months after surgery or radiation therapy. One patient had local recurrence 8 months after surgery and postoperative irradiation. No systemic toxicity such as renal failure, liver dysfunction, or bone marrow suppression was observed. Mild and transient local toxicity such as edema or mucositis of the infused area was relatively common. Trigeminal neuralgialike symptoms and reduced mouth opening occurred in two cases and one case, respectively, probably due to direct toxicity to the peripheral trigeminal nerve and masticatory muscles, respectively. CONCLUSION: Superselective intraarterial infusion of low-dose cisplatin is feasible and safe and may have important applications in treating advanced carcinoma of the mouth.

Aged↗
PubMed1995

Acute myeloblastic leukemia associated with an intermediate state between the healthy carrier state and adult T-cell leukemia.

This report describes an intermediate state between the human T-cell lymphotropic virus type I (HTLV-I) healthy carrier and adult T-cell Leukemia (ATL) who developed acute myeloblastic leukemia (AML, FAB subtype M2). The polyclonal integration of HTLV-I proviral DNA was demonstrated in the peripheral blood lymphoid cells, whereas AML cells had no HTLV-I proviral DNA. The patient achieved remission after combination chemotherapy but cells with lobulated nuclei persist at a low level and the polyclonal integration of HTLV-I proviral DNA is still demonstrated. We suggest that the patients with the integration of HTLV-I proviral DNA might develop secondary neoplasms more frequently than healthy carriers and this case stresses the need to exercise caution with these patients. The relationship between HTLV-I and AML is briefly discussed.

Adult↗
PubMed1995

[Murine "sympathetic orchitis" induced by unilateral testicular injury and autoimmune response].

BACKGROUND: Experimental autoimmune orchitis (EAO) has been studied as an animal model for human male immunological infertility. Most EAO models have been induced by immunization with testis antigens in artificial adjuvants. In this paper, we report a more clinical EAO model. METHODS: Ten to 20 needle punctures were made to the unilateral testis of mice and it was crushed by a needle-holder. RESULTS: Contralateral EAO (so-called "sympathetic orchitis") was gradually induced starting on Day 28. Delayed type hypersensitivity (DTH), one of the cell-mediated immunities, to autologous testicular cells (TC) as well as anti-TC antibodies, humoral immunity, were both detected in those mice. Repeated crush(es) of the ipsilateral testis two weeks later (and four weeks later) as a booster did not enhance the contralateral lesion or autoimmune responses. CONCLUSION: Our present injury model mimics clinical testicular trauma; therefore, this testicular injury model can be very useful in studying the immunological mechanism of EAO and of human immunological male infertility.

Animals↗
PubMed1995

[A surgical treatment of ruptured aortic dissection with non-opacified false lumen].

A 63-year-old woman was admitted to our intensive care unit suffering from severe chest pain and shock. Emergency CT scan demonstrated an acute type A aortic dissection with non-opacified false lumen and cardiac tamponade. The aortography showed ulcer like projection at the ascending aorta. An emergency operation was performed to replace the ascending aorta with a woven double-velour Dacron graft of 30 mm in diameter. It seems that an acute type A aortic dissection with non-opacified false lumen has good prognosis. The presence of other complications, however, suggests that surgical treatment should be decided upon at an early stage.

Aortic Dissection↗
PubMed1995

[TIMPs (tissue inhibitors of metalloproteinases): their species, functions and effects on tumor metastasis].

TIMPs (tissue inhibitors of metalloproteinases) belong to a family composed of three members: TIMP-1, -2 and -3. They possess a high degree similarity in their structure including 12 conserved cystenyl residues at the same relative positions. Recently, they have been shown to inhibit not only proteolytic activities of metalloproteinases but also tumor cells metastasis in vitro and in vivo. In this review, we summarize their structure information, inhibitory mechanism of metalloproteinases, TIMPs-like secretory inhibitors, other biological functions of TIMPs such as growth-regulating activity, their chromosomal localizations and related diseases. We also mention their inhibitory effects on tumor cells metastasis in vitro and in vivo, and their clinical applications.

Glycoproteins↗
PubMed1995

[Complications of percutaneous transluminal angioplasty].

Four hundred twenty-three percutaneous transluminal angioplasties with 383 percutaneous arterial punctures in 346 patients were reviewed to determine the frequency, distribution and causes of complications. Complications were seen at the angioplasty site and puncture site along with miscellaneous complications, the incidence rates being 9.5% (40 of 423 PTAs), 11.7% (45 of 383 punctures), and 2.0% (7 of 346 patients), respectively. Major complications occurred in 20 cases, and surgical procedures were required in six cases. Mortality as a complication of PTA was not seen. Angioplasty site complications included 13 spasms, eight dissections, five thromboses, 13 distal embolizations and one perforation. Most puncture site complications were benign hematomas, but there were other types such as a pseudoaneurysm requiring bypass grafting, a thrombosis requiring thrombolysis and a large quantity of bleeding requiring transfusion. The incidence of angioplasty site complications was significantly higher (p < 0.01) in the procedure for complete occlusion than that for stenosis. The puncture site and miscellaneous complications were also more frequent in complete occlusions. The incidence of complications increased with age, although this tendency did not reach statistical significance.

Adolescent↗
PubMed1995

[Cataract epidemiology survey in the three climatically different areas in Japan--prevalence of cataracts and types of lens opacification].

A cataract epidemiology study of 1,615 subjects from three climatically different places in Japan, village S in Hokkaido, town M in Noto and village Y in Okinawa, was conducted by one study group. Cataract diagnosis and grading of cataracts were objectively done with a photo-documentation system. The percentages of cataracts of over grade I classified by the Japanese Cooperative Cataract Epidemiology Study Group were 46.6%, 64.6% and 38.0% in village S, town M, and village Y, respectively. Those in their 50s, 60s, and 70s in the above places were 24.3%, 51.1% and 71.4% (village S), 38.4%, 65.3% and 84.6% (town M), and 25.2%, 42.9% and 65.4% (village Y), respectively. Cortical cataract was the most common, followed by nuclear and subcapsular types. Although the highest percentage of nuclear cataracts was seen in the subjects of village Y, subcapsular cataract was seen almost equally in the three areas. Lens transparency changes were evaluated by the light scattering intensities in the lens layers through photographed images. Intensity increased with ageing either linearly or exponentially.

Adult↗
PubMed1995

[A case of reoperation of Ebstein's anomaly with increased tricuspid regurgitation after Hardy's operation].

A 30-year-old man, who had undergone Hardy's operation and the direct closure of an atrial septal defect for Ebstein's anomaly at age 9, was reoperated on by Carpentier's procedure for a long-standing tricuspid regurgitation. He required IABP support to wean from the cardiopulmonary bypass for the acute heart failure. Nonetheless, his postoperative course was uneventful. Echocardiography, nine months after the operation, showed a decrease in moderate residual regurgitation and an increase in the right ventricular inflow velocity, which were considered signs of an improvement in the right ventricular function and, furthermore, it showed an increase in the left ventricular volume and a marked improvement in the left ventricular ejection fraction. We consider that tricuspid regurgitation for many years result in a dysfunction in the right ventricle and, because of a decrease in the filling volume, in the left ventricle. For this reason, we should positively perform an operation without leaving tricuspid regurgitation as it is.

Adult↗
PubMed1995

Testicular injury induces cell-mediated autoimmune response to testis.

Studies on testis autoimmunity are needed for a better understanding of immunological male infertility. Evidence has accumulated that the delayed type hypersensitivity (DTH) response plays a key role in the induction and/or maintenance of experimental autoimmune orchitis (EAO), an animal model for human immunological male infertility or aspermatogenesis. We report here that an antigen-specific DTH response to autologous testicular cells (TC) could be induced by bilateral testicular injury (trauma) in mice. Pretreatment of traumatized mice with a high dose of cyclophosphamide (CY) enhances the DTH response in a dose-dependent manner. The DTH response induced by testicular injury reaches its peak on the ninth day. We have shown that the local passive transfer of the footpad reaction to normal recipients by T cells further defines the DTH reaction. These characteristics resemble those of the previously reported DTH response to syngeneic TC induced by subcutaneous immunization with viable syngeneic crude TC. Our present injury model mimics clinical testicular trauma; therefore, this testicular injury model can be very useful in studying the immunological mechanism of EAO and of human immunological male infertility.

Animals↗
PubMed1995

[Surgical treatment of infective endocarditis: application of DNA probe method].

DNA probe method is a new bacteriological method for diagnosis of bacteria. The authors tried to apply the method to diagnosis of bacteremia and treatment of infective endocarditis. We could diagnose the patient's illness as bacteremia with this method even when blood cultures are not positive. We suggest that cardiac surgery should be performed in case bacteria is detected repeatedly with DNA probe method. Therefore it is useful for decision whether cardiac surgery for patients with active infective endocarditis should be done or not.

Adolescent↗
PubMed1995

[Successful treatment of aortic prosthetic valve endocarditis and aortic root abscess by Bentall procedure].

A 53-year-old woman had undergone aortic valve replacement in 1990. Three years later, aortic prosthetic valve endocarditis and aortic root abscess had been noted. Debridement of all apparently infected tissue created left ventricular-aortic discontinuity, but the orifice of the coronary arteries were intact. We decided to reconstruct the left ventricular outflow tract and aortic root by Bentall procedure. Composite graft was made with 26 mm gelseal tube graft and a 23 mm SJM prosthetic valve, and the coronary ostia were sutured into the side of the graft. The patient's recovery was uneventful, and the aortography revealed no aortic regurgitation. We suggest that Bentall procedure using gelseal tube graft is useful to reconstruct the left ventrivular-aortic discontinuity if the coronary ostia were intact.

Abscess↗
PubMed1995

Skull metastasis from hepatocellular carcinoma. CT, MR and angiographic findings.

CT, MR and angiographic findings of 6 patients with 9 skull metastases from hepatocellular carcinoma (HCC) were reviewed. In 3 of 6 patients, local pain or neurologic deficit was the initial main manifestation of the disease, although all had been treated for chronic liver disease. In the remaining 3 patients, skull metastases were detected following treatment of HCC. The metastatic lesions appeared as expansile osteolytic masses on CT and as hypervascular masses on angiography. All lesions were demonstrated on MR imaging. Compared with the brain parenchyma, the lesions were iso- or hypointense on T1-weighted and T2-weighted MR images. The lesions were moderately to markedly enhanced by Gd-DTPA. Flow voids were shown in the tumors in 5 lesions. HCC should be included in the differential diagnosis of an osteolytic hypervascular lesion of the skull, especially in Oriental patients. The relatively hypointense tumor on T2-weighted MR images associated with flow void, different from primary skull tumors or directly invasive tumors, may support the diagnosis of HCC metastasis.

Aged↗
PubMed1995

The contraction of small arteries in the perimetrium by presurgical medication with the luteinizing hormone-releasing hormone agonist to patients with leiomyomas: an electron and immunoelectron microscopy.

The remarkable contraction of small arteries occurred in the perimetrium of the uteri with leiomyomas by a presurgical medication P6th the luteinizing hormone-releasing hormone (LHRH) agonist (buserelin). The contracted vessels showed a significant increase in number of the Weibel-Palade (WP) bodies which occasionally underwent the degranulation and the discharge in a manner of exocytosis. By immunoelectron microscopy, localizations of endothelin (ET)-1 immunoreactive gold particles on the WP bodies as well as on cisterns of the rough endoplasmic reticulum (rER) and Golgi apparatus were pronounced in the buserelin-medicated group when compared to the non-medicated one. These findings indicate that the increase of the WP bodies storing ET-1, of which synthesis in the rER-Golgi system enhances, predominantly occurred in the small arteries in the perimetrium by the buserelin-medication prior to the hysterectomy. ET-1, released into the subendothelial layer, seems to play an important role in the contraction of the vascular media in a manner of paracrine.

Adult↗
PubMed1995

[Haloperidol].

Explore the source record for details and available documents.

Antipsychotic Agents↗
PubMed1995

Antitumor activity of the new selective protein kinase C inhibitor 4'-N-benzoyl staurosporine on murine and human tumor models.

CGP 41251 (4'-N-benzoyl staurosporine, CAS 120685-11-2) has been shown to exert increased selectivity for the inhibition of protein kinase C (PKC) activity. In the present study the effect of CGP 41251 formulated in gelucire as an antitumor agent was studied in various types of murine and human tumor models. When administered at a dose of 75 mg/kg 3 times daily for 9 days, CGP 41251 prolonged the life span of the mice bearing B16 melanoma (ILS = 36%). CGP 41251, administered orally at doses of 25-225 mg/kg once daily for 9 days, however, did not show distinct efficacy in four kinds of murine tumor models (B16 melanoma, colon 26, colon 38 and M5076). In s.c.inoculated human tumor xenograft models, CGP 41251, administered orally at a dose of 200 mg/kg once daily for 4 weeks showed a broad antitumor spectrum. CGP 41251 inhibited the growth of gastric cancer (H-55), colorectal cancer (H-26), breast cancer (H-31) and lung cancer (H-74 and LC-376) with inhibition rates of 58-80%. In a histopathologic study, increase in central necrosis and condensed nuclei and vacuolar degeneration were observed, but there was no structural destruction by the treatment of CGP 41251. In addition, CGP 41251 decreased the number of PCNA (proliferating cell nuclear antigen) immunoreactive cells in human tumor cells H-55, H-26 and H-74. These results indicate that CGP 41251 shows a broad antitumor spectrum against human tumors, and it is suggested that CGP 41251 is a promising oral antitumor agent which has a novel mechanism of action.

Animals↗