Search PubMed⌕ Search

Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 883 records · Page 49Linked to original sources
PubMed1985

[Diagnosis and estimation of mitral regurgitation by two-dimensional pulsed Doppler echocardiography].

The sensitivity and specificity of detecting and estimating mitral regurgitation were assessed by two-dimensional pulsed Doppler echocardiography (PDE) for 85 patients, aged 17 to 79 years. Mitral regurgitation was clinically diagnosed in 10 patients, and confirmed by angiography in 60 patients. Using real time two-dimensional images and M-mode displays, the sample volumes were taken at 36 sites, including the mitral ostium, the left atrium, and the left ventricular inflow tract. Doppler signals were analyzed by the FFT method and the diagnosis of mitral regurgitation was based on the systolic turbulence with a wide range of velocities greater than +/- 1 KHz. The results obtained were as follows: In 61 of 70 cases with mitral regurgitation, distinctly abnormal systolic Doppler signals were detected at the mitral ostium or within the left atrium, which were not recorded in the other 15 cases without angiocardiographically documented mitral regurgitation. The signals had either unidirectional or bidirectional wide frequency-band patterns, which were thought to indicate the systolic turbulence caused by mitral regurgitation, because these were occasionally recorded beyond the second heart sound, and increased with the administration of methoxamine and diminished after the inhalation of amyl nitrite. When mitral regurgitation was graded I degree, II degree, III degree and IV degree based on Sellers' classification, a PDE sensitivity for detecting mitral regurgitation was 78.1, 89.5, 100 and 100%, respectively. When approaches were divided by the parasternal long-axis, parasternal short-axis and apical long-axis, a PDE sensitivity was 80.0, 74.2, and 70.0%, respectively. The PDE was highly sensitive in diagnosing mitral regurgitation due to rheumatic valvular disease, mitral valve prolapse or ruptured chordae tendineae (sensitivity 100%), but it was less sensitive in ischemic heart disease, dilated cardiomyopathy or hypertrophic cardiomyopathy. Nine cases in which mitral regurgitation was missed by PDE, mitral regurgitation was mild (seven cases: Sellers I degree, two cases: Sellers II degree). No false positives were found. The overall sensitivity of the PDE was 87.1%, with a specificity of 100%, a diagnostic accuracy of 89.4%, and a predictive value of 100%. By displaying the distribution of systolic turbulence on parasternal or apical long-axis image (flow mapping), the direction and the extent of the regurgitant flow in the left atrium were clearly visualized. The localization of the regurgitant flow at the mitral ostium was visualized in parasternal short-axis images by the flow mapping method.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

Cell surface phenotypes and expression of viral antigens of various human cell lines carrying human T-cell leukemia virus.

Human T-cell leukemia/lymphoma virus (HTLV)-carrying cells from various origins were characterized by cell surface markers and expression of HTLV antigens. Eight cell lines named TCL were obtained by transformation of peripheral blood leukocytes (PBL) of healthy donors or HTLV carriers in cocultures with HTLV-producer MT-2 cells. Nine cell lines named ILT were interleukin 2 (IL2)-dependent cell lines cloned from PBL of ATL patients and healthy HTLV-carriers. Tc-Kan9 cell line was also an IL2-dependent cell line clonally established from PBL culture stimulated with autologous TCL cells. Five cell lines named TL were established in vitro directly from PBL of an adult T-cell leukemia (ATL) patient and from ILT cells of an ATL patient and three HTLV-carriers, respectively, to grow autonomously without IL2. All the TCLs, ILTs, TLs and Tc-Kan9 possessed Leu-I antigen, a pan-T-cell marker. Leu3a antigen, a helper/inducer T-cell marker, was expressed on five of eight TCLs and all of the ILTs and TLs. Leu-2a, a cytotoxic/suppressor T-cell marker, was detected only on Tc-Kan9 but not others. Fresh ATL leukemic cells of patients had a helper/inducer T-cell marker. Ia, OKT9 and Tac antigens, markers for activated and differentiated T cells, were strongly expressed on all of the cell lines tested and fresh ATL leukemic cells were weakly positive for these antigens. Expression of HTLV antigens detected by mouse monoclonal antibodies and an ATL-patient serum varied among these cell lines. One TL, two ILTs and most of the fresh ATL leukemic cells did not express HTLV antigens on the cell surface. The other cell lines were all positive for the surface viral antigens. However, molecular species of antigens defined by radioimmunoprecipitation with an ATL-patient serum were not always identical among the cell lines. Molecular weights of polypeptides detectable in most of the cell lines were 62K, 46K, 40K, 24K, 21K and 19K which could never be detected in several control T-cell lines. 68K and 28K polypeptides were frequently detected in MT-2 and TGLs. GIN14, a mouse monoclonal antibody against HTLV core protein (p19) detected not only p19 in various cell lines but also p28, p29, p31 or p40 in certain cell lines tested. B-cell lines named LCL were established and cloned from PBL of two HTLV-carriers by EB-virus-induced transformation and they also expressed HTLV antigens, Ia, OKT9 and Tac antigens.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Induction of digestive-tract tumors in F344 rats by continuous oral administration of N-butyl-N-nitrosourea.

Male and female F344/DuCrj rats were administered N-butyl-N-nitrosourea at a concentration of 400 ppm in their drinking water. By the 50th week of the experiment, the cumulative incidence of upper-digestive-tract tumors was as high as 35/39 (90%) and 34/39 (87%) in male and female rats, respectively. Among these, esophageal and forestomach tumors occurred most frequently. Except one female rat with fibroma, upper-digestive-tract neoplasms were of the epithelial type -- papilloma, squamous-cell carcinoma or adenocarcinoma. In female rats, vaginal tumors were induced in 16 (41%) animals. Ear-duct tumors and hematopoietic neoplasms were also induced in both sexes of rats, with incidence of less than 21%.

Adenocarcinoma↗
PubMed1984

The activity of synthetic analogs of serum thymic factor (FTS) to convert mouse pre-T cells into Thy-1 positive cells.

Serum thymic factor (FTS) and its 33 analogs were compared with regard to the ability to induce Thy-1 antigen on mouse pre-T cells. The pre-T cells were prepared from spleen cells of athymic nu/nu mice by passing them through a nylon wool column, and the induction of Thy-1 antigen was analysed using a fluorescence-activated cell sorter. Thy-1 negative cells were converted into Thy-1 positive cells by FTS and some of its analogs. Deletion of pGlu at the amino terminus of FTS did not alter the activity. Des ( pGlu1 , Ala2)-FTS and des ( pGlu1 , Ala2, Lys3 )-FTS were inactive and deletion of the carboxyl terminal residue, Asn, also resulted in the loss of activity. Substitution or modification of pGlu1 and Asn9 with an amino acid, an acyl group or an amine caused a marked reduction of the activity. The residue 3, Lys, could be substituted without any loss of the activity by Arg, but not by Leu. These results show that the octapeptide moiety, Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, is the minimum essential part of the FTS molecule for the expression of activity and they suggest that the positive charge at the residue 3 is also important for its activity.

Animals↗
PubMed1984

Paradoxical tubular obstruction after release of ureteral obstruction in rat kidney.

The healing process of hydronephrosis was studied using rat kidney. Following release of 2 weeks' unilateral hydronephrosis, renal papilla and cortex were examined by scanning electron microscopy. Shortly after the release of obstruction, massive loss of brush border and ballooning of epithelial cells were noted in proximal tubules. Distal tubules and collecting tubules also showed severe ballooning of epithelial cells. Actually most of them were completely or nearly obliterated in spite of the release of ureteral obstruction. Two weeks later, on the other hand, the many tubular components became patent with normal epithelial lining. Some of them, however, deteriorated further in spite of the release of obstruction. Thus there was a marked tubular heterogenicity in recovery. The sudden decrease of the pelvic pressure and chronic ischemic state during ureteral obstruction may cause the tubular changes which were observed in this study.

Animals↗
PubMed1984

Radioimmunoassay of serum thymic factor (FTS).

We established a radioimmunoassay (RIA) method which enables a quantitative estimation of serum thymic factor (FTS). This assay is based on the displacement of 125I-(Lys[Tyr] 3)-FTS bound to the anti-FTS antibodies by FTS. Formaldehyde-fixed Staphylococcus aureus Cowan I cells were used to precipitate the antigen-antibody complex. The anti-FTS antiserum was raised in rabbit by repeated injections of FTS-conjugated bovine serum albumin. The antiserum seemed to recognize the carboxy-terminal seven amino acid residues, Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH, of the FTS molecule. As little as 0.5 to 1 pg FTS can be detected by this method. To measure the FTS content in the serum, a serum sample was pretreated with 10% trichloroacetic acid and then with ethanol for removal of serum proteins. The FTS content in pig serum was around 22 pg/ml, and that in BALB/c mouse serum was 1.3 pg/ml. The FTS contents in the sera of DBA/2, C57BL/6 and (C57BL/6 X DBA/2)F1 mice were also less than 5 pg/ml. Since more than 70% of FTS exogenously added to pig or mouse serum was recovered, the mouse serum probably contains only a small amount of FTS.

Animals↗
PubMed1984

Studies on cation-induced membrane vesicle aggregation of porcine intestinal brush borders.

Cation specificity and effects of pH and temperature on membrane aggregation of porcine intestinal brush borders were studied in terms of the turbidity change of the membrane suspensions due to the addition of polyvalent cations. Monovalent cations (K+ and Na+) did not induce the membrane aggregation at 5 mM or below. Divalent and trivalent cations induced membrane aggregation even below 0.5 mM in the following orders of effectiveness: Hg2+ much greater than Cd2+ greater than Zn2+ greater than Mn2+ greater than Ca2+ greater than or equal to Ba2+ greater than Sr2+ greater than or equal to Mg2+ and Lu3+ greater than Yb3+ greater than Nd3+ = Er3+ = Tb3+ greater than Ce3+ greater than La3+, respectively. The aggregation of membranes induced by these polyvalent cations was reversible. Membrane aggregation induced by either divalent or trivalent cations followed saturation kinetics with increasing cation concentration and the apparent dissociation constants of these cations for the membranes were estimated to be at 4-6 mM for divalent cations (Ca2+, Mn2+, and Sr2+) and 1-2 mM for trivalent cations (Lu3+, Tb3+, and La3+). Cd2+ and Hg2+ had peculiarly much lower dissociation constants than any other divalent cations tested, being rather comparable to trivalent ones. The membrane aggregation induced by Ca2+, Mn2+, or Sr2+ was independent of pH in the range of 6.6 to 8.0, whereas that induced by Tb3+ or Cd2+ was linearly enhanced with increasing pH, very steeply above pH 7.0. The membrane aggregation induced by Cd2+, Hg2+, or Tb3+ was enhanced steadily with increasing temperature between 15 and 45 degrees C. On the other hand, Ca2+-induced aggregation showed a peak at around 30 degrees C in the temperature dependence profile, still being enhanced above 40 degrees C.

Animals↗
PubMed1984

Assessment of left ventricular function in ischemic heart disease. The relation between pressure decay during the isovolumic relaxation phase and regional wall motion abnormality.

We examine whether regional wall motion abnormality (RWMA) could contribute to the slowed relaxation rate of the left ventricle (LV) in patients with coronary artery disease (CADpts). Simultaneous observations were made on the time constant (Tc) of the isovolumic pressure decay and left ventriculography at the control period and after right atrial pacing. Subsequently, the subjects investigated were divided into 3 groups, i.e. normal subjects (Group I, n = 8), CADpts with normal wall motion during the control period (Group II, n = 21), and CADpts with RWMA during the control period (Group III, n = 28). The latter two groups were further divided into two subgroups according to the presence (Group IIa and IIIa) or absence (Group IIb and IIIb) of pacing-induced RWMA. We measured Tc by a method of exponential analysis that could estimate the asymptote. During the control period, Tc was significantly prolonged in Group III (82 +/- 26 msec) than that in Group I (60 +/- 6 msec) and Group II (63 +/- 12 msec). Tc was prolonged in proportion to the extent of RWMA during the control period. Immediately after right atrial pacing, Tc was markedly prolonged in Group IIa (from 61 +/- 12 to 90 +/- 20 msec, p less than 0.001) and in Group IIIa (from 73 +/- 26 to 95 +/- 34 msec, p less than 0.001). The post-pacing prolongation of Tc was closely correlated with the extent of post-pacing RWMA. From these results, it is postulated that RWMA may play an important role as a causes of the altered LV relaxation in CADpts.

Adult↗