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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 271 records · Page 15Linked to original sources
PubMed1993

Giant cell tumor of tendon sheath. An immunohistochemical observation on the characteristics and the capacity of proliferation of tumor cells.

To investigate character and proliferation of tumor cells of giant cell tumor of tendon sheath (GCTTS), we studied 25 cases of GCTTS by light and electron microscopic immunohistochemistry. Mononucleated stromal cells (SC) of GCTTS could be divided into three types according to their antigenic features. The first type was the histiocytic SC expressing antigens recognized by KP1, Mac387 and Ham56. The second type was the fibroblastic SC showing fibronectin immunoreactivity. The third type was the intermediate SC expressing both KP1 and fibronectin. The presence of intermediate SC suggested that the different types of SC of GCTTS would be of common origin, i.e. from the mesenchymal cells of the synovium and represented different functional phases or phenotypic alterations. The expression of proliferating cell nuclear antigen (PCNA) was observed only in SC and occasionally, in binucleated cells, but multinucleated giant cells (GC) were negative for PCNA, suggesting that GC were non-dividing cells.

Antigens, Neoplasm↗
PubMed1993

A newborn case of extrarenal malignant rhabdoid tumor.

Malignant rhabdoid tumor is initially differentiated from renal tumors and characterized by extremely rapid growth. We report a newborn case of extrarenal malignant rhabdoid tumor and review the literature.

Diagnosis, Differential↗
PubMed1993

Effects of substituents on the acid-catalyzed photoreaction of pyrimidine derivatives in p-xylene.

In order to obtain insight into the protonation of the electron adducts of pyrimidine bases (I) and the chemical behavior of the resulting radicals under an acidic condition, the photoreaction of 5-substituted 1,3-dimethyluracil (1) (substituents; p-xylyl, methyl, H, Cl, and F) was performed in p-xylene (2) in the presence of a large amount of trifluoroacetic acid (TFA). 5, 6-dihydrouracil derivatives (3), 5-p-methylbenzyluracils (4) and the 6-isomers (5) were yielded as the major products. Substitution of an electron-releasing group (p-xylyl) at C-5 raises the ratio of the products from the C6-protonated pyrimidine electron adduct (III) (3, 4) vs. the adduct from the O4-protonated isomer (II) (5), while the electron-withdrawing substituents (F > Cl) suppress the ratios.

Acids↗
PubMed1993

[Surgical treatment of pseudoaneurysm of the left ventricle after myocardial infarction--a case report].

A 62-year-old woman had myocardial infarction with congestive heart failure. Follow-up chest X-rays showed progressive prominent bulging of the left cardiac silhouette. Echocardiography revealed a large echo-free space behind the posterior of the left ventricle. Magnetic resonance imaging and left ventriculogram confirmed the huge pseudoaneurysm of the left ventricle. We performed the operation 4 months later the onset of the myocardial infarction. The pseudoaneurysm was opened under cardio-pulmonary bypass. It contained a large amount of old thrombi and communicated with the left ventricle through several orifices in the inferior left ventricular wall. The orifices were closed primarily with pledged mattress and running sutures. The aneurysmal wall was left unresected. The pathologic study showed no myocardial element nor endocardium in the aneurysmal wall. Postoperative course was uneventful, and she discharged from the hospital in a healthy condition.

Diagnosis, Differential↗
PubMed1993

[Acute aortic dissection after coronary revascularization--a case report].

A 59-year-old man with coronary artery disease and arteriosclerosis obliterans of left lower extremity underwent anastomosis of left internal thoracic artery to left anterior descending artery with cardiopulmonary bypass of aortic perfusion and left femoro-popliteal bypass with saphenous vein graft. On the first postoperative day, urinary output decreased and then stopped. The transesophageal echocardiography and angiography revealed the Stanford A type acute aortic dissection. Immediately the resection of the ascending aorta including the intimal tear, which was found on the site of the previous aortic perfusion, and the reconstruction of the ascending aorta with the prosthetic graft was performed. After the reperfusion of left femoral artery, which was used as the route of the arterial perfusion during cardiopulmonary bypass, serum potassium level increased gradually and at last the heart was arrested. Hemodialysis with draining from inferior vena cava produced the stability of hemodynamics, but on the next day he died of low cardiac output syndrome. We presented the case with the acute aortic dissection after open heart surgery, which was one of the rare complications in aortic perfusion of cardiopulmonary bypass and emphasized the possibility of occurrence of myonephropathic-metabolic syndrome after the repair of acute aortic dissection with limb ischemia.

Acute Disease↗
PubMed1993

[Effects of air injection on hemodynamics and sympathetic nerve activity in urethane-anesthetized rabbits].

We designed this experiment to evaluate effects of intravenous bolus injection of air (0.5 ml.kg-1) on systemic blood pressure (SBP), central venous pressure (CVP), and renal nerve activity (RNA) in urethane-anesthetized rabbits. Animals were divided into the following three groups: animals with neuraxis intact (I group, N = 5), cervical vagotomized animals (V group, N = 5) and sinoaortic denervated animals (SAD group, N = 4). All animals were placed on the right-side down position to avoid effects of the posture throughout the experiments of air embolism. In the I group, air caused profound hypotension (from 95 +/- 10 to 54 +/- 15 mmHg) associated with a significant increase in CVP (from 2 +/- 2 to 7 +/- 3 mmHg) twenty seconds after the injection of air. In spite of the significant hypotension, RNA response did not show any increase for twenty seconds. This response was followed by an augmentation in RNA thirty seconds after air injection. In contrast, vagotomized animals exhibited a significant RNA increase (147 +/- 11% of the control) in response to a decrease in SBP (from 93 +/- 6 to 78 +/- 5 mmHg) and an increase in CVP ten seconds after the administration of air. In SAD group, a rapid and remarkable decline in SBP (from 85 +/- 13 to 47 +/- 12 mmHg) occurred ten seconds after the injection of air. Despite this hypotension, RNA decreased nearly to a noise level after administration of air.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1993

[Re-operation for total anomalous pulmonary venous connection twelve years after radical operation].

Thirty five-year-old man required reoperation, twelve years after radical operation of total anomalous pulmonary venous connection (Darling IIb type), because of the clinically apparent pulmonary venous obstruction. The stenosis of ASD was revealed by cineangiocardiography and echocardiography. The fibrous thickening of atrial septal wall and stenosis of ASD were found at the operation. Operating procedure consisted of the enlargement of ASD and cut-back of the atrial septal wall. Postoperative study showed no evidence of stenosis of pulmonary venous return. The patient was discharged well and returned to his job. Late postoperative pulmonary venous obstruction is of particular concern. Usually it occurs within the first few postoperative months. We reported this case because it is rare that pulmonary venous obstruction occurred twelve years after radical operation.

Adult↗
PubMed1993

Osteocalcin levels in maternal and cord blood.

OBJECTIVE: To measure osteocalcin levels in fetal and maternal blood. METHODS: Osteocalcin was measured by radioimmunoassay in paired maternal and umbilical venous and arterial blood obtained at term deliveries. RESULTS: Umbilical venous osteocalcin levels (mean +/- standard deviation) were significantly higher than arterial levels (10.28 +/- 4.99 versus 3.85 +/- 2.27 micrograms/L). Umbilical venous but not arterial levels of osteocalcin were significantly higher than maternal values (2.54 +/- 1.19 micrograms/L). CONCLUSION: Higher osteocalcin levels in umbilical venous blood than in umbilical arterial blood suggest that the placenta may be the main source of osteocalcin in late fetal life.

Female↗
PubMed1993

[Primary chylopericardium with skeletal lymphoangiomatosis: a case report].

A 5-year-old girl admitted to our hospital complaining cardiomegaly due to pericardial fluid and punched-out area in the humerus. Analysis of pericardial fluid confirmed primary chylopericardium and the findings in the humerus suggested skeletal lymphoangiomatosis. Despite medical treatments, pericardial fluid didn't decrease. Therefore, she underwent ligation and resection of thoracic duct. She recovered uneventfully without reaccumulation of the pericardial effusion. In addition, skeletal survey resulted in lymangiomatosis.

Bone Neoplasms↗
PubMed1993

[Clinical significance of micromegakaryocytes in de novo AML].

Bone marrow specimens obtained from 54 patients with de novo AML and 7 patients with AML evolving from MDS were retrospectively examined for the presence of micromegakaryocytes defined as cells of less than 30 microns in diameter with one or two nuclei. At least 25 megakaryocytes were counted in each patient. Micromegakaryocytes were found in 17 cases (31%), M1:1/11, M2:5/18, M3:0/4, M4:5/12, M5:1/4, M6:4/4, M7:1/1. The median age of the patients was higher in de novo AML with micromegakaryocytes (57 years) than in de novo AML without micromegakaryocytes (41 years) (p = 0.014). Chromosomal analysis revealed that deletion of 5 or 5q-, 7 or 7q- was recognized only in the group of de novo AML with micromegakaryocytes and that t(15;17), t(8:21) and inv (16) were not recognized in this group. Micromegakaryocytes were identified in each bone marrow specimen obtained from 9 of 10 patients with de novo AML with trilineage myelodysplasia. The complete remission rate was significantly lower in de novo AML with micromegakaryocytes (33%) than in de novo AML without micromegakaryocytes (86%) (p = 0.001). The duration of survival of the patients with de novo AML with micromegakaryocytes was shown to be shorter than that of the patients with de novo AML without micromegakaryocytes (p = 0.017). Micromegakaryocytes were recognized in all of 7 patients with AML evolving from MDS. The presence of micromegakaryocytes in bone marrow of the patients with AML indicates a subset of AML with poor prognosis that may be closely associated with myelodysplastic syndrome.

Adolescent↗
PubMed1992

Epoxyeicosatrienoic acid stimulates ADP-ribosylation of a 52 kDa protein in rat liver cytosol.

In rat liver cytosol, rapid ADP-ribosylation of a 52 kDa protein by endogenous ADP-ribosyltransferase(s) was observed. This ADP-ribosylation was stimulated dose-dependently by 14,15-epoxyeicosatrienoic acid (14,15-EET), one of the metabolites of arachidonic acid by NADPH-dependent cytochrome P-450 mono-oxygenase. This stimulatory effect required the presence of GTP or its non-hydrolysable analogues, guanosine 5'-[beta gamma-imido]triphosphate or guanosine 5'-[gamma-thio]triphosphate. Of four regioisomeric EETs, 14,15-EET was the most potent. No stimulatory effect was observed with addition of 14,15-dihydroxyeicosatrienoic acid, a stable metabolite of 14,15-EET. The 52 kDa protein was not ADP-ribosylated by cholera toxin A subunit and pertussis toxin, and was not recognized by anti-Gs alpha and anti-Gi alpha antibodies. However, the 52 kDa protein could be photoaffinity-labelled with 8-azidoguanosine 5'-[alpha-32P]triphosphate. These results suggest that the 52 kDa protein is neither Gs nor Gi, though it may have a GTP-binding site. These results contribute to the understanding of the role of mono-oxygenase metabolites of arachidonic acid in intracellular signal transduction.

8,11,14-Eicosatrienoic Acid↗
PubMed1992

Malignant peripheral nerve sheath tumors: an immunohistochemical study in relation to ultrastructural features.

The constituent cells in malignant peripheral nerve sheath tumors were examined by studying the expression of immunohistochemical markers for Schwann cells and perineurial cells in relation to ultrastructural features in 12 malignant peripheral nerve sheath tumors. Ultrastructural studies demonstrated mixed proliferation of Schwann cells, perineurial cells, fibroblastic cells, and primitive cells in many malignant peripheral nerve sheath tumors. Expression of S-100 protein was well correlated with Schwann cell-like differentiation of tumor cells. However, Leu-7 and epithelial membrane antigen, which have been considered to be specific to Schwann cells and perineurial cells, respectively, were common to Schwann cells, perineurial cells, and primitive cells. The common immunophenotypic expression suggests a close relationship among these cell types. The unusual expression of cytokeratin could be explained by the plasticity of intermediate filament expression.

Adult↗
PubMed1992

Prostaglandins and premenstrual syndrome.

We examined plasma PGF2 alpha, PGE, PGE2, TXB2 and 6-keto-PGF1 alpha at intervals throughout 3 menstrual cycles in 20 patients with PMS. Similar measurements throughout 1 menstrual cycle were made in 12 age-matched control women. The plasma concentration of PGF2 alpha in the late luteal phase was significantly lower in patients with PMS compared with that in the control subjects. The plasma concentrations of PGE in the middle follicular phase and middle luteal phase, PGE2 alpha in the middle follicular phase and TXB2 in the middle and late luteal phase were significantly higher in 20 patients compared with the values in the controls. A disturbance of PG metabolism may contribute to the etiology of PMS.

Adolescent↗
PubMed1992

Cutaneous leiomyosarcoma.

A child's head-sized tumor on the upper back developed in a 43-year-old man. In spite of an extensive operation for the tumor, he died of multiple metastasis 15 months after the operation. Histologically, tumor cells proliferated throughout the dermal and subcutaneous regions, and a boxed-in appearance was noted with silver staining. Because electron microscopic observations strongly suggested a smooth muscle origin, we diagnosed this case as cutaneous and subcutaneous leiomyosarcoma.

Adult↗
PubMed1992

Intracellular localization of Staphylococcus aureus within primary cultured mouse kidney cells.

Staphylococcus aureus Cowan I was incubated with monolayers of cells derived from several portions of mouse kidney, and found to be ingested by all types of the renal cells. Intracellular localization of S. aureus was determined by resistance of intracellular cocci against lysostaphin digestion and confirmed by electron microscopy. From renal medulla, three morphological variants of the hyperosmolarity-tolerant (HOT) cells were obtained. The rate of cocci-ingesting cells varied from 16.9% to 93.4% among these of the HOT cells at the end of 3-hr incubation. From renal cortex, three morphological variants of epithelial cells grew in medium RK-1. Among them, only the cells on the edge of colony ingested Cowan I, while the epithelial cells on the center of colony ingested few cocci. Transferred from medium RK-1 to MEM supplemented with 10% FBS, part of the cortical cells changed into fibroblast-like appearance and obtained the capacity to ingest Cowan I. This result may indicate the correlation between ingesting capacity and cellular morphology. From a glomerulus, epithelial (GE) cells and fibroblast-like (GF) cells were obtained. The GE cells ingested not only S. aureus Cowan I but Staphylococcus epidermidis and Staphylococcus saprophyticus after 30-min incubation, while the GF cells, like both of the HOT cells and the cortical cells, ingested only S. aureus. These results suggest a possibility that S. aureus is located within nonprofessional phagocytes during its infection and intracellular coccus plays an important role in its pathogenicity.

Animals↗