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Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 649 records · Page 36Linked to original sources
PubMed1992

Primary mesenchymal chondrosarcoma of the lung. A case report with immunohistochemical and ultrastructural studies.

A case of primary pulmonary mesenchymal chondrosarcoma is reported. The tumor occurred first in the lower lobe of the right lung of a Japanese female aged 45. Three years after the first operation it metastasized to the upper lobe of the left lung. The tumors were highly cellular and composed of undifferentiated mesenchymal cells and interspersed islands of well-differentiated cartilaginous tissue. Immunohistochemistry failed to detect S-100 and vimentin in the undifferentiated cells. In contrast, Leu-7 and blood coagulation factor XIIIa were positive in these cells. Electron microscopically, undifferentiated mesenchymal cells had narrow cytoplasm with sparsity of organelles, but no intermediate-sized filaments were detected. In the transitional areas between undifferentiated cells and cartilaginous components, thin intracytoplasmic filaments were sometimes observed in the tumor cells. The differentiation toward cartilaginous cells of undifferentiated mesenchymal cells was suggested by immunohistochemistry and electron microscopy. This is the first case of mesenchymal chondrosarcoma occurring in the lung with long-term follow-up.

Chondrosarcoma↗
PubMed1992

[Ergometric and pathologic study of a family with complex I deficiency].

We studied a family with a myopathic form of complex I deficiency with regard to the clinical symptoms, usefulness of the exercise tolerance test with an ergometer for screening of mitochondrial abnormalities, pathological findings in biopsied muscles and genetics. In this family, none of the members had disorders of the central nervous system, such as convulsions, mental deterioration or stroke-like episodes. In the two affected generations, three mothers and three children had mitochondrial abnormalities. Two children were diagnosed as having complex I deficiency. One of them, an 8-year-old girl with normal psychomotor development during infancy, began to experience easy fatigability at about 3 years of age. At the age of 5 years, she experienced respiratory distress and became unconscious. Thereafter, she had similar episodic respiratory problems with lactic acidosis. Ragged-red fibers and respiratory chain enzyme defects were detected in the biopsied muscle. Another child, a 15-year-old boy with easy fatigability but no muscle weakness, had normal respiratory chain enzyme activities and a normal oxysogram: oxygen consumption showed a normal responses when malate and pyruvate were added as substrates for the isolated mitochondria. His muscle pathology revealed rare ragged-red fibers and abnormal subsarcolemmal mitochondrial aggregation. An investigation with an ergometer showed elevated serum lactate and pyruvate levels. Only one mother had muscle weakness and hyper-lactic acidemia. The other two mothers had no muscle symptoms, but abnormal results were obtained with the ergometer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Oxygen utilization, carbon dioxide elimination and ventilation during recovery from supine bicycle exercise 6 to 8 weeks after acute myocardial infarction.

The pattern of oxygen (O2) consumption (VO2), carbon dioxide (CO2) production (VCO2), ventilatory and metabolic responses during and in recovery from supine bicycle exercise was examined in 18 patients with recent myocardial infarction. An increase in VO2 with increasing work load was accomplished by proportional increases in both cardiac output and the arteriovenous O2 difference. During recovery, however, the arteriovenous O2 difference rapidly decreased below levels at rest, whereas VO2 and cardiac output remained elevated, indicating that VO2 during recovery further depended on relatively high cardiac output. The ratio of VCO2 to VO2 further increased after exercise, suggesting that such cardiac output contributed to the remaining high CO2 flow to the lung and therefore enhanced ventilation. Increased arterial catecholamines during exercise remained elevated for the first 5 minutes of recovery. Arterial lactate during this period continued to increase and resulted in profound metabolic acidosis, causing alveolar hyperventilation after exercise. These results suggest that during recovery from exercise, cardiopulmonary responses remain enhanced because of continuing high cardiac output, resulting in subsequent high CO2 flow to the lung and metabolic acidosis, and that this may be associated with profound fatigue or dyspnea after exercise.

Acidosis, Lactic↗
PubMed1991

Doppler assessment of right ventricular filling dynamics during volume loading in ischemic heart disease.

To assess the effects of volume loading on right ventricular (RV) filling dynamics, the RV inflow pattern was recorded using pulsed Doppler echocardiography (PDE) during dextran infusion in 7 normal subjects (Group I) and 24 patients with ischemic heart disease. The patients with ischemic heart disease were divided into three groups according to the left ventricular (LV) and RV ejection fractions (EF). Group II consisted of 11 patients whose LVEF and RVEF exceeded 50%. Group III consisted of 7 patients whose LVEF was lower than 50% and RVEF was higher than 50%. Group IV was comprised of 6 patients whose LVEF and RVEF were lower than 50%. Peak flow velocity of the RV rapid filling wave in early diastole [R(T)] and that of the atrial contraction wave [A(T)] were measured, and the ratio of A(T) to R(T) [A(T)/R(T)] in each cardiac cycle was calculated. In some of the subjects, simultaneous right-sided cardiac catheterization was performed with a Swan-Ganz thermodilution catheter. The LV and RV function during volume loading were calculated according to the following formulae: delta Stroke volume index (SVI)/delta pulmonary artery wedge pressure (PAWP) and delta SVI/delta right atrial pressure (RAP), respectively. After dextran infusion, R(T) increased significantly in Groups I, II, and III, but not in Group IV. The A(T) and A(T)/R(T) ratio remained unchanged in all groups. The percent change of the R(T) correlated well with delta SVI/delta RAP (r = 0.56, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Primary culture and cryopreservation of mouse astrocytes under serum-free conditions.

The methods of primary culture and cryopreservation of mouse astrocytes under serum-free conditions were examined. Cerebra from newborn C3H/He mice were employed as the source of astrocytes. The cultured cells were able to grow in a serum-free, chemically defined medium containing transferrin, hydrocortisone, biotin, sodium selenite, insulin, fibroblast growth factor and epidermal growth factor. After the culture was maintained in the medium for 3 weeks, purity was assessed using immunofluorescence staining. The great majority of the cells (greater than 98%) contained glial fibrillary acidic protein and S-100 protein which are cell markers of astrocytes. To cryopreserve the enriched astrocytes under serum-free conditions, various cryoprotectants were examined. The combination of 10% dimethylsulfoxide and 0.1% methylcellulose gave the highest survival rate. These methods of primary culture and cryopreservation will be useful in physiological and biochemical studies which require mouse astrocytes.

Animals↗
PubMed1991

Expression of fibronectin and laminin by different types of mouse glial cells cultured in a serum-free medium.

The expression of fibronectin and laminin by cultured glial cells was studied. The glial culture from neonatal mouse cerebra maintained in a chemically defined, serum-free medium consisted of type-1 astrocytes, oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells, oligodendrocytes and type-2 astrocytes. Double-labelling immunofluorescent experiments performed using the mixed glial culture indicated that fibronectin and laminin are expressed in different patterns among the glial subtypes. The staining intensities with anti-fibronectin or anti-laminin antibodies decreased in the order: type-1 astrocytes, O-2A progenitor cells and type-2 astrocytes. Both molecules were deposited in a fibrillar matrix underneath type-1 astrocytes, whereas only intracytoplasmic localization of these molecules was observed with O-2A progenitor cells and type-2 astrocytes. Western blot analysis showed that glial fibronectin has a slightly higher molecular weight than mouse plasma fibronectin (230 kDa) and that glial laminin is a variant with a 220 kDa B chain present and the 400 kDa A chain missing. Using enzyme-linked immunosorbent assays (ELISA), these molecules were detected in the glial extracellular matrix at the concentration of 4 ng/10(6) cells. A large amount of fibronectin (82 ng/10(6) cells) was secreted into the culture medium, while secretion of laminin was not detected.

Animals↗
PubMed1991

In vitro bone resorption by isolated multinucleated giant cells from giant cell tumour of bone: light and electron microscopic study.

The behaviour of multinucleated giant cells (GCs), obtained from a giant cell tumour of the tibia and cultured on glass coverslips or on devitalized bone slices, was studied using light and electron microscopy. Monitoring the GCs on bone slices by phase-contrast microscopy revealed that they had removed calcified bone matrix resulting in excavation of lacunae, with subsequent lateral extension and perforation of the bone slices. Electron microscopy demonstrated for the first time that the GCs responsible for exavating lacunae had two specific membrane modifications, ruffled border and clear zone, and showed basically similar cytoplasmic fine structures to those of osteoclasts. Fluorescence images of the GCs on glass and on bone after rhodamine-conjugated phalloidin staining revealed that most of the GCs had an intensely fluorescent peripheral band composed of a number of F-actin dots called podosomes. Some GCs showed unusual arrangements of podosomes suggesting abortive attempts at GC formation. We have demonstrated that the band structure of the GCs cultured on bone is intimately involved in bone resorption. Two stromal cell types could be recognized. The predominant type, which seemed to be the only neoplastic element because of its proliferative capability, showed quite different fine structural and cytoskeletal features from the GCs. The other type, which was much less frequent and seemed not to proliferate, had morphological similarities to the GCs, and seemed to be their precursor. Importantly GCs cultured on bone and the osteoclasts share common structures for adhesion to and resorption of bone, strongly supporting the view that the GCs of the giant cell tumour of bone are potentially active bone resorbers and can be regarded as osteoclasts.

Adult↗
PubMed1991

Cepharanthine inhibits two-stage tumor promotion by 12-O-tetradecanoylphorbol 13-acetate and mezerein on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene.

Cepharanthine, isolated from Stephania cepharantha, is one of the bisbenzylisoquinoline-type alkaloids. We have found that it inhibits tumor promotion after topical application in two-stage carcinogenesis in mouse skin. Epidermal ornithine decarboxylase activities inhibited by topical application of cepharanthine, with an 5 micrograms/mouse) and mezerein (5 micrograms/mouse) were found to be inhibited by topical application of cepharanthine, with a ED50 of 1.2 mumol and 1.4 mumol respectively. These inhibitory effects of cepharanthine are considered to be related to its antitumor activity in two-stage carcinogenesis in mouse skin. Cell-mediated immunosuppression by TPA was unaffected by topical application of cepharanthine. A diet containing 0.005% cepharanthine (about 0.5 mg mouse-1 day-1) slightly suppressed the two-stage promotion of skin tumors by twice-weekly applications of 2.5 micrograms TPA for 2 weeks (first stage) followed by twice-weekly applications of 2.5 micrograms mezerein for 23 weeks (second stage) in ICR mice following initiation by 50 micrograms 7,12-dimethylbenz[a]anthracene. Oral administration of cepharanthine inhibits the tumor promotion in two-stage carcinogenesis in mouse skin.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Factors associated with atrial fibrillation in Q wave anterior myocardial infarction.

To elucidate the role of inflammatory and hemodynamic factors in the genesis of atrial fibrillation in acute myocardial infarction, 228 patients with a first Q wave anterior myocardial infarction were studied. Forty-nine patients had pericarditis (detection of pericardial rub by careful auscultation), and 36 patients had echocardiographically demonstrated hydropericardium (presence of pericardial effusion without pericardial rub). During the first 3 days after admission, transient episodes of atrial fibrillation were observed in 10 patients (20%) with pericarditis (group 1), 15 patients (42%) with hydropericardium (group 2), and 20 patients (14%) without pericarditis and hydropericardium (group 3). Although there was no significant difference in the incidence of atrial fibrillation between groups 1 and 3, patients in group 2 had a significantly higher incidence of atrial fibrillation than those in groups 1 and 3. Pulmonary capillary wedge pressure and the number of advanced asynergic segments were found to be the important factors discriminating the three groups by multivariate analysis. Therefore atrial fibrillation after acute Q wave anterior infarction was not related to the inflammatory infiltration involving the atria but to the increase in atrial pressure resulting from hemodynamic change caused by more extensive myocardial damage.

Atrial Fibrillation↗
PubMed1991

Mixed venous oxygen saturation as a guide to tissue oxygenation and prognosis in patients with acute myocardial infarction.

The relation of mixed venous oxygen saturation and the cardiac index to tissue oxygenation and prognosis was investigated in 119 patients with acute myocardial infarction. There was a positive correlation between mixed venous oxygen saturation and the cardiac index in 97 survivors and 22 nonsurvivors, but a significantly lower mixed venous oxygen saturation level at the same level of cardiac index was observed in nonsurvivors compared with survivors. Results of multivariate analysis with mixed venous oxygen saturation and the cardiac index indicated that only mixed venous oxygen saturation was significantly related to survival and to hyperlactacidemia. Oxygen delivery to tissues declined significantly in nonsurvivors because of a lower cardiac index and a lower hemoglobin concentration in these patients than in survivors. However, at the same level of oxygen delivery to tissues, nonsurvivors had a significantly higher rate of oxygen consumption leading to a correspondingly greater decrease in mixed venous oxygen saturation, suggesting that a greater increase in oxygen demand was also observed in nonsurvivors than in survivors. Thus mixed venous oxygen saturation after acute myocardial infarction is a better predictor of hyperlactacidemia and survival than the cardiac index, and this may be associated with an increased oxygen demand and an impaired oxygen transport system in seriously ill patients.

Aged↗
PubMed1991

Production of platelet-like particles by a human megakaryoblastic leukemia cell line (MEG-01).

The distribution of microtubules and platelet-specific glycoproteins (GPIIb/IIIa) in particles was probed by an immunofluorescence method using anti-tubulin and anti-GPIIb/IIIa antibodies to identify whether particles released from a human megakaryoblastic cell line (MEG-01) are platelets. The fluorescence image showing anti-tubulin staining of the particles revealed a characteristic ring structure observed in platelets. Anti-platelet GPIIb/IIIa antibody staining showed an image in which small patches or spots were seen throughout the particle with brighter staining at the periphery. No significant difference was observed between these particles and human blood platelets under immunofluorescent staining. These results show that MEG-01 cells released platelet-like particles.

Blood Platelets↗
PubMed1991

Studies on the carotenoids in the muscle of salmon--V. Combination of astaxanthin and canthaxanthin with bovine serum albumin and egg albumin.

1. Bovine serum albumin (BSA) and/or egg albumin were bound to astaxanthin or canthaxanthin easily and the spectroscopic characteristics of these complexes were similar to those of astaxanthin or canthaxanthin in the salmon muscle. 2. This result indicates that astaxanthin-BSA, -egg albumin, canthaxanthin-BSA and -egg albumin complexes were basically similar to astaxanthin-actomyosin and/or canthaxanthin-actomyosin complex in the salmon muscle. 3. The binding of salmon actomyosin to astaxanthin or canthaxanthin is not specific.

Actomyosin↗
PubMed1991

Differential responses of p56lyn and p53lyn, products of alternatively spliced lyn mRNA, on stimulation of B-cell antigen receptor.

We previously cloned a lyn cDNA-encoding 56-kd Src-like protein-tyrosine kinase, p56lyn. Anti-Lyn antibodies raised against a sequence of 95 amino acids (Arg-25 to Ala-119 of p56lyn) recognized two species of the protein, p56lyn and p53lyn. V8 proteinase analysis showed that p53lyn differs only slightly from p56lyn. Analysis of mRNA from B lymphocytes by the polymerase chain reaction indicated the presence of two forms of alternatively spliced lyn mRNA. Nucleotide sequencing of the corresponding cDNAs revealed that these two forms of lyn mRNA differ in the presence and absence of a 63 nucleotides sequence near the 5'-terminus of the coding region; 21 amino acid residues (Pro-23 to Arg-43 or Val-24 to Pro-44) of p56lyn were tentatively concluded to be missing in p53lyn. On cross-linking of the membrane-bound IgM (mIgM) on the surface of B lymphocytes, the kinetics of down-regulations of the two Lyn proteins demonstrated to be associated with the mIgM antigen receptor were found to be different. This observation suggests that the amino terminal proximal sequence of the Lyn protein is important for determining its mode of interaction with mIgM.

Amino Acid Sequence↗
PubMed1991

Structures and functional roles of the sugar chains of human erythropoietins.

Erythropoietin (EPO) is a haemopoietic hormone specific to cells of erythroid lineage. EPO has recently become available for the treatment of anaemia as the first human recombinant biomedicine produced in heterologous mammalian cells. Human EPO is characterized by its large carbohydrate chains, which occupy close to 40% of its total mass. These sugar moieties were thought to be important for the biological activity of EPO, but detailed studies were not performed until the structures were elucidated. The variety of roles for the sugar chains were then immediately found once the structures were known. EPO is an excellent model for investigating the roles of sugar chains on glycoproteins, since its gene and its multiple glycoforms are available, as well as sensitive bioassays for testing. In this review, we will first summarize the known sugar chain structures of EPO from different host cells, and then discuss the host-cell dependent and peptide structure-dependent glycosylation of glycoproteins. We will then address how one investigates the roles of sugar chains of glycoproteins, show several examples of such investigations, and discuss the functional roles of HuEPO's sugar chains in its biosynthesis and secretion, its in vitro and in vivo biological activities, and its half-life in blood circulation.

Carbohydrate Sequence↗
PubMed1991

Increased extravascular lung water in patients with low pulmonary artery occlusion pressure after acute myocardial infarction.

OBJECTIVE: To evaluate the clinical characteristics of increased extravascular lung water (EVLW) in patients with low pulmonary artery occlusion pressure (PAOP) in the early phase of acute myocardial infarction. DESIGN: Consecutive sample for descriptions of the clinical features of medical disorders. SETTING: A general medicine group practice in a university hospital. PATIENTS: Sixteen patients with low PAOP (less than 18 mm Hg) on the initial measurement obtained within 12 hr of chest pain onset. MEASUREMENTS AND MAIN RESULTS: EVLW was measured by the thermal indocyanine green dye double-indicator dilution method. QRS score was obtained on hospital day 7 from the Selvester's QRS Scoring System. Eleven (69%) patients had increased EVLW greater than 7 mL/kg despite low PAOP. EVLW had no significant correlation with PAOP and the difference between plasma colloid osmotic pressure and PAOP, but did have a significant correlation with pulmonary vascular resistance index (r2 = .31, p less than .05), and QRS score (r2 = .45, p less than .005). CONCLUSIONS: Larger infarcts led to increased EVLW even with low PAOP, and the accumulation of increased EVLW around the small arterioles might have led to increased pulmonary vascular resistance.

Blood Pressure↗
PubMed1991

Spontaneous development of autoimmune uveoretinitis in nude mice following reconstitution with embryonic rat thymus.

This paper describes the spontaneous occurrence of an autoimmune uveoretinitis in nude (nu/nu) mice reconstituted when 4 weeks old by the grafting of rat embryonic thymus. The uveoretinitis was characterized histologically by progressive loss of the photoreceptor layer, observed in 4.0, 17.6, 42.9% and 71.4% of such mice at 3, 5, 7 and 12 months of age, respectively. Mice with uveoretinitis were shown to have serum IgG antibody reactive by indirect immunofluorescence with retinal photoreceptors, and with interphotoreceptor retinoid-binding protein (IRBP), but not retinal S-antigen, by immunoblotting and ELISA. A uveoretinitis could be adoptively transferred to syngeneic ungrafted nude mice by splenic CD4+ T cells from diseased animals. This is the first experimental model of a (T cell mediated) autoimmune uveoretinitis which develops spontaneously and which is not dependent upon deliberate sensitization with retinal antigens and adjuvants.

Animals↗