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Biomedical subjects

T Katsuki

Publications and source records attributed to T Katsuki.

At least 109 records · Page 6Linked to original sources
PubMed1988

Portopulmonary shunt by splenopneumopexy for portal hypertension in children.

Portopulmonary shunting by splenopneumopexy was successfully performed on seven children with portal hypertension, associated with extrahepatic portal vein occlusion in six and congenital hepatic fibrosis in one. Technically, this procedure is very simple and safely performed even in infancy. No operative mortality has been encountered to date. All children with portal hypertension treated by this portopulmonary shunt are doing very well, without any disturbances in their growth. Their postoperative survival ranges from 8 years and 9 months to 17 years and 9 months. Splenic pulp pressure was reduced to a postoperative mean value of 306 +/- 40.7 mmH2O from a preoperative mean value of 402.9 +/- 35.7 mmH2O. Hemorrhages esophageal varices were completely controlled postoperatively. Postoperative liver function tests were essentially unchanged from the preoperative values.

Child↗
PubMed1988

"Transformation" of human endothelial cells by SV40 virions.

Human endothelial cells derived from the umbilical vein were transformed with SV40 virions. A cell line subcultured for over 60 serial passages was characterized in comparison with its untransformed counterpart which was culturable for less than five passages. The SV40-transformed human endothelial cells, designated SV-HUVEC, were positive not only for tumor (T) antigen specific to the SV40-transformed cell, but also for two markers of endothelial cells, Factor VIII-related antigen and a receptor for Ulex europaeus agglutinin I. By transformation the growth potential of the human endothelial cells was increased and their serum requirement was decreased. The SV40-transformed endothelial cells were, however, unable to form colonies in soft agar or to form tumors in athymic nude mice, although a small nodule was produced at the site of inoculation. Subcultivation of these cells up to the 62nd passage eventually resulted in crisis and loss of further cell division. Thus, the human endothelial cells were transformed by SV40 while retaining certain normal functions but without showing tumorigenicity.

Animals↗
PubMed1988

Combination therapy with diltiazem and nifedipine in patients with effort angina pectoris.

The antianginal effects of diltiazem and nifedipine alone and in combination were evaluated in a double-blind, randomized, placebo-controlled trial in 11 patients (nine men and two women, 57 +/- 8 years old) with stable effort angina. Each patient received placebo, 30 mg of diltiazem, 10 mg of nifedipine, and 30 mg of diltiazem plus 10 mg of nifedipine four times daily for 1 week each. Antianginal efficacy was assessed by means of a treadmill exercise test. The exercise tolerance time was significantly prolonged from 235.1 +/- 52 (placebo period) to 342.2 +/- 101 sec by diltiazem (p less than .01) and to 325.6 +/- 73 sec by nifedipine (p less than .01). The drug combination further prolonged exercise time to 451.1 +/- 103 sec, which was significantly longer than the interval attained with either diltiazem (p less than .01) or nifedipine (p less than .01) alone. The plasma concentration of diltiazem was unaffected by the addition of nifedipine, whereas the plasma nifedipine concentration was significantly increased from 34.8 +/- 11 to 106.4 +/- 37 ng/ml (p less than .001) by the concomitant administration of diltiazem. These data suggest that exercise tolerance in patients with effort angina is increased by the concomitant administration of diltiazem and nifedipine associated with an increase in the nifedipine plasma concentration.

Adult↗
PubMed1988

Differences in regulatory mechanisms of atrial and ventricular muscle contraction in bovine heart.

The purpose of this study was to characterize the regulatory mechanisms of atrial muscle contraction. Natural actomyosin (NAM) and tropomyosin-troponin (TM-TN) complex were prepared from atrial and ventricular muscle of the same bovine heart. The results were as follows: (1) Atrial NAM was more sensitive to Ca2+ than was ventricular NAM: the pCa required for 50% ATPase activation was 5.96 +/- 0.10 vs. 5.63 +/- 0.07, (mean +/- SE; n = 6; p less than 0.01); (2) reconstitution of desensitized actomyosin of rabbit skeletal muscle plus atrial or ventricular TM-TN complex produced higher Ca2+ sensitivity in atrial muscle than in ventricular muscle: the pCa required for 50% ATPase activation was 6.48 +/- 0.10 vs. 6.23 +/- 0.15 (n = 3; p less than 0.05); (3) the amount of inorganic phosphate covalently bound to atrial NAM was equivalent to that bound to ventricular NAM; (4) SDS-polyacrylamide gel electrophoresis of the two NAMs revealed several protein bands of different mobility from 16,000 to 30,000 daltons; and (5) the superprecipitation response of atrial NAM was characterized by a stepwise change in turbidity after the addition of MgATP, in contrast to the biphasic pattern of ventricular NAM. These data suggest that the free Ca ion concentration required for atrial muscle contraction is lower than that required for ventricular muscle contraction and that the difference is attributable to differences in atrial and ventricular regulatory proteins.

Actomyosin↗
PubMed1988

[Establishment and characterization of human colonic and gastric cancer cell lines].

Two human cancer cell lines, DAIT-6 from a colonic cancer and IT-25 from a gastric cancer, derived from xenografts in nude mice have been established in tissue culture and maintained for over two years. In tissue culture, DAIT-6 cells grew in a monolayered sheet with a population doubling time of about 45.0 hr, and floated or piled up to form small buds above the monolayered surface in relatively confluent cultures. Chromosomal counts ranged from 40 to 108 with a modal number of 59. The cells secreted CEA (1.7 ng/1 x 10(6) cells/24 hr) and CA19-9 (540.5 u/1 x 10(6) cells/24 hr) in spent medium. The IT-25 cells grew in a monolayered sheet with a population doubling time of about 57.8 hr in tissue culture. The IT-25 cells also secreted CEA (0.5 ng/1 x 10(6) cells/24 hr) and CA19-9 (120.0 u/1 x 10(6) cells/24 hr) in spent medium. The xenografts for DAIT-6 and IT-25 in nude mice were histopathologically classified as a moderately differentiated tubular adenocarcinoma and a well differentiated tubular adenocarcinoma, respectively.

Adenocarcinoma↗
PubMed1987

Internalization of serratial protease into cells as an enzyme-inhibitor complex with alpha 2-macroglobulin and regeneration of protease activity and cytotoxicity.

Extracellular serratial protease (56,000 Da) is known to be cytotoxic. Fluorescein isothiocyanate-labeled protease was found to form a complex with human alpha 2-macroglobulin (alpha 2M), and this enzyme-inhibitor complex was purified. The protease was found to be internalized by fibroblasts in culture as a complex with alpha 2M, which resulted in cell destruction. Regeneration of enzyme activity was confirmed in cells after 2-3 h of incubation. Chicken egg-white ovomacroglobulin, a homolog of human alpha 2M, formed a complex with this enzyme similarly and more tightly but failed to exhibit protease activity, cytotoxicity, and internalization into cells.

Binding, Competitive↗
PubMed1987

New approach in the management of oesophageal varices.

Combined therapy consisting of sclerotherapy, embolization and splenopneumopexy was established for the treatment of oesophageal varices. These procedures were safely performed in 16 patients. No serious complications and no recurrent bleeding have been observed. The varices disappeared or were significantly improved as determined by periodic endoscopic evaluations. Portopulmonary shunt by splenopneumopexy is an alternative technique in the eradication of varices following sclerotherapy.

Combined Modality Therapy↗
PubMed1987

Kinetics of carcinoembryonic antigen and carbohydrate antigen 19-9 production in a human pancreatic cancer cell line (SUIT-2).

Kinetics of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) production in a human pancreatic cancer cell line (SUIT-2) were investigated. Production of CEA reached a maximum, 31.0 ng/1 X 10(6) cells, in the late stationary phase with transient decline during the early exponential phase and 15.5% of the produced CEA was released into the medium, while production of CA19-9 reached a maximum, 421 U/1 X 10(6) cells, in the early stationary phase and 68.8% of the produced CA19-9 was released into the medium. Accordingly, the kinetics of CEA and CA19-9 production of SUIT-2 in vitro might be independent. CEA was stained immunohistochemically in the cytoplasm of the cells forming small buds above the monolayer cell sheet. On the contrary, CA19-9 positive cells were observed scattered in the monolayer cell sheet and CA19-9 was stained in the cytoplasm, predominantly at the projections of the cell surface. CEA and CA19-9 were also detected in the sera of nude mice bearing SUIT-2 tumors and their concentrations correlated well with tumor volume. Correlation coefficients between tumor markers and tumor volume were 0.79 (p less than 0.01) for CEA and 0.90 (p less than 0.01) for CA19-9.

Animals↗
PubMed1987

Evaluation of diseased coronary arterial branches by polar representations of thallium-201 rotational myocardial imaging.

The perfusion territories in polar representations of stress Tl-201 rotational myocardial imaging in patients with angina pectoris who had one diseased coronary segment were analyzed. The lesions proximal or distal to the first major septal perforator in left anterior descending arteries were detected by the presence or absence of defects at the base of the anterior septum. Right coronary artery lesions were detected by the presence of defects at the basal posterior septum, in contrast to the preservation of myocardial uptake at this portion in lesions of the left circumflex artery. The specific defect patterns were detected in cases with lesions at the first diagonal, obtuse marginal, and posterolateral branches. Recognition of these defects in the polar maps allows detailed detection of diseased coronary arterial branches.

Adult↗
PubMed1987

Immune suppression in healthy carriers of adult T-cell leukemia retrovirus (HTLV-I): impairment of T-cell control of Epstein-Barr virus-infected B-cells.

We have examined the activities of Epstein-Barr virus (EBV)-specific memory T-cells of carriers of adult T-cell leukemia (ATL) associated retrovirus (HTLV-I) and non-carriers in an ATL-endemic area, all of whom were EBV-seropositive, by assay of EBV-induced B-cell focus regression. The result showed that immune suppression, as represented by lowering of the regression, was present in 18 (29%) out of 63 healthy HTLV-I carriers, in contrast to none of 63 matched control persons (healthy non-carriers). This finding suggests that a suppression of cell-mediated immunity is induced by a persistent infection with ATL retrovirus.

Adult↗