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Biomedical subjects

K Sekiguchi

Publications and source records attributed to K Sekiguchi.

At least 235 records · Page 13Linked to original sources
PubMed1982

Competition for cellular receptor sites among selected aphthoviruses.

The competition between different types of aphthoviruses (foot-and-mouth disease virus [FMDV]) for receptor site utilization was determined. The Southern African Territories (SAT) types of FMDV absorbed poorly to BHK-21 cells as measured by a radioactivity binding assay but grew to relatively high titers on these cells. On BK cells, however, all three SAT types bound well and competed with each other for receptor sites. In addition, unlabeled FMDV types A12 and O1B were able to completely inhibit the binding of 3H-uridine labeled SAT types. Unlabeled SAT, however, was only slightly able to inhibit the adsorption of labeled A12 and moderately inhibit the binding of labeled O1B. Saturation binding studies with homologous virus showed that BK cells contain at least 100-fold more receptor sites for types A12 and O1B than for the SAT types. Competitive binding analysis between type A12 FMDV and poliovirus and encephalomyocarditis virus revealed that these three viruses all used different receptor sites. Thus, different FMDV serotypes appear to utilize both common and unique receptor sites which are different from those of at least two other picornaviruses.

Animals↗
PubMed1982

Further observation on empyema after resection of bronchogenic carcinoma and survival.

Out of 11,247 cases undergoing resectional therapy for bronchogenic carcinoma at 39 institutions, 6,348 were operated before July 1976 and the remaining 4,899 thereafter. Analyzing both series, the following results were obtained: 1) The rate of pneumonectomies to lobectomies was 1:2.3 in the former and 1:3.9 in the latter. Pneumonectomies were more on the left side, whereas the right lobectomies were about twice as many as the left ones. 2) Postoperative empyema occurred in 180 cases (2.8%) in the former and 79 cases (1.6%) in the latter. The incidence was significantly higher in the cases of right pneumonectomy than in the cases of left pneumonectomy, and in the cases of pneumonectomy than in the cases of lobectomy. Although the incidence of postpneumonectomic empyema decreased only slightly, overall incidence decreased significantly because of marked increase of lobectomy cases. 3) Out of 180 cases of empyema in the former series, 17 died within 30 days. 4) The 5-year survival rate of the patients with empyema was 28 per cent. 5) The 5-year survival rate was 30 per cent in 93 cases of squamous cell carcinoma, 30 per cent in 50 cases of adenocarcinoma and 15 per cent in 13 cases of large cell carcinoma. There was no survivor among 7 cases of small cell carcinoma. 6) Out of 259 cases of empyema, micro-organisms were cultured in 161 cases, were negative in 20, and unknown in 78. Although various organisms were found, gram-negative bacteria and Pseudomonas were most frequently isolated, i.e. 37 per cent and 36 per cent, respectively. 7) As for the treatment of 5-year survival cases of empyema, thoracoplasty and bronchial closure were frequent as compared with open thoracic window technics such as Eloesser's and Symbas' operation. And, more than half of the cases of empyema seem to have been complicated with bronchial fistulae.

Adenocarcinoma↗
PubMed1981

Virus-induced fusion of human erythrocyte ghosts. I. Effects of macromolecules on the final stages of the fusion reaction.

Human erythrocyte ghosts prepared by hypotonic hemolysis can be fused by Sendai virus, provided that certain macromolecules (bovine serum albumin, dextran and others) are sequestered in the ghosts. Since fusion of the ghosts is dependent on intactness of the F(fusion)-glycoprotein of the virion, and since the other requirements for this reaction are also similar to those for the Sendai virus-induced fusion of intact erythrocytes, this system can be used as a model for the Sendai virus-induced cell fusion reaction. Sequestered macromolecules seem to be required for rounding of locally fused ghosts. Under low osmotic swelling conditions, such as use of ghosts sealed without macromolecules or using bovine serum albumin-loaded ghosts sealed in the presence of external macromolecules, no apparently complete cell fusion (large spherical polyghost formation) could be observed. Even under these conditions, however, occurrence of local cell fusion could be demonstrated either by transfer of fluorescent-labeled albumin from one ghost to an other, or by observation of polyghost formation after osmotic swelling in the cold. Thus, final stages of the fusion reaction can be divided into local cell-cell fusion which could not be observed by phase-contrast microscopy, and rounding (i.e. formation of spherical polyghosts). For the observation of fusion of ghosts, the last step seems to be important.

Albumins↗
PubMed1981

[A case of deep sylvian meningioma with intracerebral hematoma (author's transl)].

A case of deep sylvian meningioma is reported which is unusual in the aspect that the initial symptoms were headache and vomiting due to intracerebral hemorrhage from meningioma. After evacuation of hematoma in the right temporal lobe and biopsy of the tumor, it was found to be meningothelial meningioma with psammoma bodies. Cerebral angiography showed characteristic findings of intrasylvian vascular tumor. Complete removal of this tumor was performed under microscopy, dissecting dense adhesion between the tumor and main branches of the middle cerebral artery. Consequently, the patient showed only slight impairment of fine movement of his left fingers. Deep sylvian meningioma designated by Cushing and Eisenhart is very rare. This case is the only one of deep sylvian meningioma in our whole series of 181 intracranial meningiomas and probably the twentieth case reported so far in the literature.

Cerebral Angiography↗
PubMed1980

Preliminary evaluation of intratumoral injection of a Streptococcus pyrogenes preparation in patients with malignant brain tumors.

Thirteen patients with malignant brain tumors, 12 anaplastic gliomas and one metastatic tumor, received repeated intratumoral injections of an immunopotentiator, Picibanil, prepared from streptococcus pyogenes. All patients tolerated this therapy; morbidity rates were acceptable. Significant tumor regression was noted on computerized tomography scanning for 6 of 12 patients for whom scanning was performed. Histologic examination of the post-therapy specimens obtained from 8 patients revealed that inflammatory reactions were evoked in all of the tumors, although the extent of inflammatory changes varied from patient to patient and mostly was localized to an area surrounding the intratumoral tubes.

Adjuvants, Immunologic↗
PubMed1980

Functional domain structure of fibronectin.

Structural domains of fibronectin (FN) and their ability to associate with cell surface components have been systematically investigated. Plasma FN was cleaved into three structural domains (Mr 150,000-140,000, 40,000, and 32,000) by sequential digestion with trypsin and thermolysin. A single digestion with thermolysin alone generated Mr 150,000-140,000, 40,000, and smaller fragments. With the inclusion of thermolysin, but not with other proteases, one can, with a high yield dissect FN simultaneously into three clearly distinctive functional domains. Of three major fragments only the Mr 40,000 fragment bound to a gelatin column; this fragment contained essentially all of the carbohydrates present in the original FN. In contrast, heparin-binding sites were localized on both the Mr 150,000-140,000 and 32,000 fragments but not on the Mr 40,000 fragment. Only the Mr 150,000-140,000 fragments and intact FN promoted cell spreading, whereas the Mr 40,000 and 32,000 fragments could induce cell attachment but failed to promote cell spreading. These results indicate that FN is composed of (at least) three structural domains that are functionally distinct from each other.

Animals↗