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S Yamagata

Publications and source records attributed to S Yamagata.

At least 109 records · Page 6Linked to original sources
PubMed1990

Two-dimensional mapping by the high-performance liquid chromatography of oligosaccharides released from glycosphingolipids by endoglycoceramidase.

A two-dimensional sugar mapping method has been developed by which sensitive, reproducible, and simple analysis can be carried out on the structures and compositions of oligosaccharides released from glycosphingolipids by endoglycoceramidase. The oligosaccharides were labeled quantitatively with an ultraviolet-absorbing compound, p-aminobenzoic acid ethyl ester (ABEE). The ABEE-oligosaccharides were separated first on an amide-silica column and then on a C4-silica column by high-performance liquid chromatography. The acidic ABEE-oligosaccharides were eluted as a group at the start of the chromatography while the neutral ABEE-oligosaccharides were separated according to size and structure on an amide-silica column using an eluent without salt. The acidic oligosaccharides were separated according to size and structure when rechromatographed on the same column using an eluent containing KH2PO4. NeuAc-containing ABEE-oligosaccharides were extensively separated from the corresponding NeuGc derivatives. The ABEE-oligosaccharides separated on an amide-silica column were then chromatographed on a column of C4-silica on which lactotriose and neolacto-series oligosaccharides were clearly shown to be separated from the others. On the basis of the retention times of the individual ABEE-oligosaccharides on two separate columns, 9 neutral and 15 acidic oligosaccharides derived from glycosphingolipid standards were two-dimensionally mapped without overlapping. The gangliosides of a human chondrosarcoma tissue and glycosphingolipids of tumor tissue of FBJ virus-transformed murine osteosarcoma cells were analyzed by this method in conjunction with exoglycosidase treatment. At least 11 species of glycosphingolipids were identified in both cases.

Animals↗
PubMed1990

Human papillomavirus infection of the uterine cervix analyzed by nonisotopic in situ hybridization.

Some types of human papillomaviruses (HPVs) have been suggested to be strongly related to uterine cervical carcinoma. An attempt to detect these in formalin-fixed, paraffin-embedded sections was made by either immunohistochemical or by in situ hybridization. Anticapsid protein of bovine papillomavirus antibody labeled with peroxidase was used for immunohistochemistry, and biotin was used instead of radioisotopes to label probes for in situ hybridization, which resulted in low background and a rapid procedure. Condylomatous changes were stained immunochemically with this antibody even in invasive carcinoma, whereas the carcinoma itself was not stained. Direct correlation was demonstrated by in situ hybridization between the HPV genome and histopathological structure, which was impossible by Southern or dot hybridization. HPV DNAs were detected in the nuclei of koilocytes and dyskeratinocytes of condylomata and dysplasias. Furthermore, hybridization signals of HPV DNAs in basal and parabasal cells suggested that HPV infection had already begun in the basal cells. In the case of malignant neoplasia accompanied by dysplasia, the same type of HPV was detected both in the malignant neoplasia and accompanying dysplasia. In one case of intraepithelial carcinoma, the very small focus of carcinoma just arisen in the cells of dysplasia was identified, and both were positive for HPV 18. This fact supports the suggestion that the carcinoma arises in dysplasia. Invasive carcinomas were classified further into keratinized, large-cell nonkeratinized, and small-cell nonkeratinized types, and the positive frequency for HPV 16 decreased as the differentiation of the carcinoma decreased. In the case of keratinized type of invasive carcinoma, strong hybridization signals were prominent around the malignant pearl formation.

Adult↗
PubMed1990

Treatment of a giant aneurysm of the cavernous internal carotid artery associated with a persistent primitive trigeminal artery: case report.

A case of an unruptured giant aneurysm of the cavernous portion of the left internal carotid artery associated with a persistent primitive trigeminal artery (PTA) is presented. The usual surgical approach to giant aneurysms at this site, including ligation of the ipsilateral internal carotid artery (ICA) and an extracranial-intracranial (EC-IC) bypass, was inadequate because of continued blood supply to the aneurysm via the PTA from the vertebrobasilar system. The patient was successfully treated with a combination of EC-IC bypass surgery, ICA ligation, and simultaneous intravascular balloon obliteration of the ICA just distal to the junction of the PTA and immediately proximal to the aneurysmal neck. Follow-up radiological investigations showed thrombosis of the aneurysm.

Carotid Artery, Internal↗
PubMed1990

Glucose consumption and rate constants for 18F-fluorodeoxyglucose in human gliomas.

To investigate the value of direct measurement of the rate constants by performing 18F-labeled fluorodeoxyglucose (FDG) studies of glucose consumption in human gliomas in vivo, a kinetic method with 3- and 4-parameter rate constant models for FDG uptake was used to analyze data from dynamic scans obtained by positron emission tomography after injection of FDG into 14 patients with glioma. The results were compared with those obtained by the autoradiographic method using 3- and 4-parameter rate constant models. There were no significant differences in the glucose consumption calculated by the four different methods both in the gliomas and in the contralateral intact cortex. It was found that the rate constant k4* could be neglected in calculation of glucose consumption in gliomas as well as in the contralateral intact cortex. The rate constant k3*, an index of hexokinase function, was higher in malignant gliomas than in benign gliomas and was close to that in the contralateral cortex. This study indicates that the 3-parameter autoradiographic method, which is the most common one used in clinical practice, is reliable for the calculation of glucose consumption in human gliomas. Furthermore, direct measurement of the regional rate constants for FDG by the kinetic method was found to be useful for evaluation of the biochemical and physiological characteristics of human gliomas in vivo.

Adult↗
PubMed1990

[Chemotherapy of cancer of the cervix].

Systemic chemotherapy has been widely used for the purpose of inducing remission of advanced cancer of the cervix. Almost all anti-cancer drugs have been applied to this way of chemotherapy, however, the high effectiveness of cisplatin is worthy of notice, and this drug plays a central role in combination chemotherapy. Local hyperthermia, drug-induced hypertension and intra-arterial infusion of anti-cancer drugs are the representative methods to reinforce the effect of chemotherapy. Adjuvant chemotherapy has to be designed to adapt the extremely slow growing potential of residual microcarcinomas after surgery. Oral administration of tegafur for two years is a choice of maintenance chemotherapy preventive against postoperative recurrence.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Intraluminal thrombosis and growth-mechanism of giant intracranial aneurysms].

12 giant intracranial aneurysms were studied by MRI. Intraluminal thrombosis was observed in 9 aneurysms. Thrombosis was found more frequently in larger aneurysms. Thrombi were formed posteriorly or inferiorly in the lumen of 4 among 5 IC-cavernous aneurysms. Location of the neck of the aneurysms and stagnation of blood flow influenced by gravity may be causative factors determining the location of thrombi. In 6 aneurysms intraluminal thrombi were inhomogeneous on MRI, suggesting that the thrombi had been formed at different times. New thrombi were formed between the aneurysmal wall and the old thrombus in 3 cases. Dissection of the aneurysmal wall by residual blood flow in the lumen or hemorrhage in the aneurysmal wall may be one of the growth mechanisms of giant intracranial aneurysms.

Adolescent↗
PubMed1990

[Improvement in the mechanical properties of artificial blood vessel suitable for the extracranial cerebral artery].

Saphenous vein interposition grafts have been commonly used for the reconstruction of occlusive lesions in the extracranial cerebral vessels, such as carotid or vertebral arteries. In contrast, cerebral revascularization using an artificial blood vessel has not been so common. This is due to the fact that conventional artificial blood vessels have been too firm or too rigid for use in the neurosurgery. Another reason is that the long term patency rate of small caliber artificial blood vessels has usually been inferior to that found in autologous vein grafts. The purpose of this study was to develop a soft and compliant artificial blood vessel suitable for cerebrovascular surgery. This new artificial blood vessel is made of polyurethane, porous in structure (porous polyurethane). Thus, multiple small-sized pores exist both in the inner and outer surfaces, and in the wall of the porous polyurethane graft. To test its mechanical properties, we evaluated stress-strain curves and compliance. In comparison to expanded polytetrafluoroethylene graft (Goretex), which has been one of the most commonly used artificial blood vessels in the cardiovascular surgery, the mechanical properties of the porous polyurethane graft more closely resembled those of the common carotid artery in dogs. Thus, porous polyurethane graft was shown to be a soft and compliant new artificial blood vessel. This means not only that it can be maneuvered with technical ease for anastomosis but also that there is a reduction of compliance-mismatch between the host vessel and the artificial vessel. Compliance mismatch has been documented as a major factor in the inducement of intimal hyperplasia, which causes a delayed occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Gelatinases of murine metastatic tumor cells.

The properties of gelatinases secreted in culture medium of murine fibroblasts, macrophages, colonic carcinoma, FBJ virus-induced osteosarcoma, Lewis lung carcinoma and mammary tumor cells were compared. Normal fibroblasts and macrophages secreted gelatinases of 60,000 and 95,000 molecular weights, respectively. Tumor cells secreted both of these gelatinases, although the relative amounts of the 60 kDa and 95 kDa gelatinases differed among the cell lines. The cell lines that had the greatest metastatic potential to the lung secreted the highest amount of 95 kDa gelatinase. The 95 kDa gelatinase produced by tumor cells had properties similar to that of macrophages.

Animals↗
PubMed1989

Regional cortical blood flow during extra-intracranial bypass surgery in young patients with moyamoya disease.

Regional cortical blood flow (rCBF) was measured with a thermal diffusion flow probe in 14 cortical regions of 12 young patients with moyamoya disease before and after completion of superficial temporal-middle cerebral artery anastomosis. The prebypass rCBF value was low in most patients, especially in the frontal regions. On temporary occlusion of the cortical artery during the surgical procedure, no significant drop in rCBF occurred. rCBF increased immediately after anastomosis in all but one region and continued to increase for 5-10 minutes in four of the eight regions measured. In the other four regions, rCBF declined gradually after the initial increase, and the final increase was slight. The average increase in rCBF was significant at 1-2 minutes and at 5-10 minutes after anastomosis. However, the latter increase did not bring the flow into the normal range. It may be that the initial increase in postbypass rCBF is determined solely by the pressure gradient between the donor and recipient arteries, and that subsequent rCBF is controlled by other factors within the brain. In one patient who underwent double anastomoses to the frontal and temporal lobes, neither anastomosis increased rCBF in the non-corresponding lobe to recipient artery. This suggests that there is no direct connection between supra- and infra-Sylvian arteries and supports the concept of nonuniform epicerebral microcirculation in moyamoya disease.

Adolescent↗
PubMed1989

Comparison of dynamic and xenon computed tomography in the evaluation of cerebrovascular ischemia.

Dynamic computed tomographic (DCT) scans with iodine contrast enhancement were compared with simultaneously obtained xenon CT studies of cerebral blood flow (CBF) in 15 patients with subacute or chronic cerebrovascular ischemic disease. Specifically, the width and corrected first moment (cMT1), as demonstrated by DCT, were compared with the regional CBF (rCBF) data and the rCBF map obtained with xenon CT. The DCT and rCBF images were well correlated in patients without, but poorly correlated in those with, leptomeningeal anastomotic collateral circulation. The correlation of rCBF and 1/width with 1/cMT1 was significant (r = 0.78, p less than 0.01) in the former, but not in the latter. These data were thought to reflect a difference in the tracer inflow pattern between the patients with and those without leptomeningeal anastomoses. Our series did not include patients with acute cerebral infarction or recanalization, which are thought to be associated with marked changes in cerebral blood volume in the affected region. However, the influence of cerebral blood volume should be studied in detail in our subacute or chronic series.

Brain Ischemia↗
PubMed1989

[The application of vascular endoscope for the extracranial cerebrovascular occlusive disease: the development of the endoscopic system].

Flexible thin fiber catheter is applied as vascular endoscope for occlusive lesions in the extracranial cerebral arteries. This fiber catheter is introduced transfemorally through 6 or 7 french-sized double lumen balloon catheters. Vascular endoscope clearly demonstrates the internal surface of these vessels by transient occlusion of the proximal side of the vessel through balloon inflation. The occlusive lesions in the subclavian artery or in the proximal vertebral artery were revealed as round smooth-surfaced mass to be treated by the percutaneous transluminal angioplasty.

Aged↗
PubMed1989

[Study of the clinical background and therapeutic method in patients with vulvar cancer].

Forty-two cases of vulvar cancer were reviewed with regard to clinical condition and therapeutic method, especially the efficacy of local administration of BRM. By histological examination, koilocytosis was found in 45%. Furthermore, there was 90% positive koilocytosis rate in immunohistological study using anti-human papilloma virus antibody and in situ hybridization method by HPV DNA probe (type 6, 11, 16, 18). The HPA was mostly type 16. Therefore, vulvar cancer was considered to occur in close relation with HPV type 16. Some 12% of vulvar cancer was complicated with other gynecologic cancer. In these cases, NK activity was low. Thus, cancer may be considered to occur in association with low immunological status. With regard to the therapeutic method, surgery and radiotherapy were usually used after chemotherapy in our institute. At stage 3-4, combination therapy using surgery and radiotherapy were found to be most effective. In regard to local immunotherapy using OK-432 and LAK cell and IL-2, local administration of OK-432 was effective. Therefore, surgery and radiotherapy with local immunotherapy after chemotherapy were considered to be the most effective therapeutic method for vulvar cancer.

Aged↗
PubMed1989

[Human papilloma virus (HPV) antigens and DNA in dysplasia and carcinoma of the uterine cervix].

Routinely paraffin-embedded sections of dysplasia, carcinoma in situ (CIS) and invasive (squamous) carcinoma of the cervix were studied to determine the participation of human papilloma virus (HPV) in these tissues. Morphological observation (1,059 cases) revealed condylomatous changes to reach 54% in dysplasia, 25% in CIS and 25% in invasive carcinoma. Condylomatous changes were also found to be 25 to 40% in the non-cancerous epithelia adjacent to in situ or invasive carcinomas. The immuno-peroxidase-PAP-method using anti-HPV serum was applied to 98 selected sections in which condylomatous changes were morphologically observed. HPV antigens were found to reach 56% in dysplasia, 42% in CIS and 35% in invasive carcinoma, and this result suggested that the morphologically observed condylomatous changes did not always coincide with virus maturation in the infected cells. By means of the in situ hybridization technique, HPV type-6, -11, -16 and -18 DNAs were all detected in dysplasia sections, whereas HPV type-16 DNA was demonstrated distinctively at a high rate among in situ and invasive carcinomas.

Antigens, Viral↗
PubMed1989

[Estrogen production in epithelial tumors of the ovary--clinical and endocrinological study in postmenopausal women].

Estrogen-producing activity of common epithelial tumors (54 cases) and metastatic tumors (4 cases) of the ovary was clinically and endocrinologically studied in postmenopausal patients. High serum concentrations of E1 (greater than or equal to 50 pg/ml) and E2 (greater than or equal to 30 pg/ml) were demonstrated in 78% in the group of postmenopausal patients. Mucinous tumors were more commonly associated with high estrogen levels than serous tumors. Patients with malignant tumors more frequently have a high level of serum estrogen than those with benign tumors. Estrogen decreased to normal after complete resection of the tumor, but returned to the abnormal range following a recurrence. The local-peripheral gradient of the estrogen level was noted by measuring the estrogen concentration in the blood of the affected ovarian and peripheral veins at the time of laparotomy. These results indicated that serum estrogen in the patient was originally produced in the ovarian tumor mass. The increased estrogen were reflected in such target tissues as the endometrium and vaginal mucosa. Proliferation, hyperplasia, atypical hyperplasia and even a case of carcinoma of the endometrium were observed in patients with ovarian tumors. An increase in the karyopyknotic index (KPI) of the vaginal smear, as well as uterine bleeding, could be an important signs of asymptomatic ovarian tumors in postmenopausal women.

Biomarkers, Tumor↗
PubMed1989

[Estrogen production in epithelial tumors of the ovary--identification of estrogen-synthesizing cells].

Morphological, fine structural and enzyme histochemical investigation of common epithelial tumors of the ovary was aimed at identifying the estrogen-synthesizing cells in the stroma of the tumor. Histological changes in cell condensation or "thecosis" and cell enlargement or "luteinization" were commonly observed in the stromal area of the tumor. Two types of stromal cells were found by electron microscopic study; one had characteristic organelles of steroid hormone-producing cells, and the other had a similar cytoplasmic structure to that of fibroblastic cells. Both types of cells had lipid droplets in the cytoplasm. The former seemed to be transformed from the latter. Steroidogenesis-related enzymes such as 3 beta-hydroxy steroid dehydrogenase (HSD) and 17 beta-HSD were demonstrated in the stromal cells. Electron microscopy revealed that these enzymes were localized at the intercrystal space and inner membrane of mitochondria with tubular crystal. These findings indicated that thecosis appeared in the stroma of the epithelial tumor, and the stromal cell acquired estrogen-producing potential.

Cytoplasm↗