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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 1,027 records · Page 57Linked to original sources
PubMed1985

A new method for obtaining scanning electron microscopic images of the reorganization process of human dermal microvascular endothelium in vitro.

A new method for obtaining scanning electron microscopic images of the reorganization process of endothelial cells has been developed. When covered with a collagen-coated disk, all the cultured endothelial cells reorganized on the collagen of the disk, which was easily taken out from the dish to process for SEM. The reorganization process could be divided into four stages: endothelial cell growth (Stage 1), reticular network formation (Stage 2), tubular structure formation (Stage 3), and cytolysis of the tube (Stage 4). Between Stages 1 and 2 the endothelial cells transformed from a cobblestone to a spindle-shaped pattern and fused each other, forming a board-like structure. Between Stages 2 and 3 break up of parts of the board-like structure and outflow of a necrotic mass from the centre of the structure occur. At Stage 3 a tubular structure is formed following enwrapping of the cleared centre by the surrounding endothelial cells. This method produces a means to study the angiogenesis in a variety of disorders including tumours and wound-healing process using SEM.

Cells, Cultured↗
PubMed1985

Involvement of different receptor subtypes for the production of in vitro and in vivo effects in a series of synthetic enkephalin analogues.

Enkephalin analogues of tyrosyl group on the N-terminal and Phe-ol or phenylethylamine (PHA) group on the C-terminal which are connected with different chain length were tested for their activities in vitro and in vivo. The inhibitory effect of the synthetic peptides on the electrically evoked contractions of isolated longitudinal muscle strips of guinea pig ileum were weaker than that of morphine or Leu-enkephalin and tended to decrease by increasing the number of methylene group,-(CH2)n-, n = 1-5, between N- and C-terminal. Compounds with PHA group on the C-terminal, n = 4 and 5, showed the least activity. The effect of peptides with short chains of methylene groups, n = 1 or 2, and Phe-ol on the C-terminal were antagonized by naloxone but others were insensitive to naloxone. Differing from in vitro activity, compounds with PHA on the C-terminal with a chain of 4 methylene groups produced short lasting analgesia after i.c.v. injection as well as the compounds with Phe-ol on the C-terminal and 1 or 2 methylene groups. The analgesic effect of these compounds were completely antagonized by naloxone. At a high i.c.v. dose, all the synthetic peptides, except the one with PHA on the C-terminal with a chain of 4 methylene group, produced convulsions and/or ipsilateral rotation to the injection side. These behavioral effects were not antagonized by naloxone. Thus, minor alterations in the chemical structure of enkephalin analogues resulted in the changes of their receptor selectivity and potencies in vitro and in vivo.

Analgesia↗
PubMed1985

Purification and characterization of four isolectins of mushroom (Agaricus bisporus).

Four lectins were purified from a mushroom (Agaricus bisporus) by ammonium sulfate fractionation, anion-exchange chromatography, affinity chromatography on bovine submaxillary mucin-Sepharose 4B and preparative isoelectric focusing. They were designated as ABA-I (pI 6.70), II (pI 5.98), III (pI 5.69) and IV (pI 5.53). Polyacrylamide gel electrophoresis of each lectin in the presence of sodium dodecyl sulfate gave a single band with an apparent molecular mass of 16 000 Da. Sedimentation equilibrium analysis suggested that each lectin is a tetramer of subunits. The four lectins were found to have quite similar carbohydrate-binding specificities. The hemagglutination activities of the lectins were effectively inhibited by bovine and porcine submaxillary mucins (BSM and PSM), and NH2-terminal glyco-octapeptides obtained by cyanogen bromide cleavage of human erythrocyte glycophorin A. In addition, desialylated PSM-glycopeptides were more potent inhibitors than untreated PSM-glycopeptides. Among monosaccharides and their glycosides, only methyl N-acetyl-alpha-galactosaminide inhibited lectin binding at a high concentration, but a synthetic oligosaccharide, O-beta-galactopyranosyl-(1----3)-O-(2-acetamido-2-deoxy-alpha-D- galactopyranosyl)-N-tosyl-L-serine, was a strong inhibitor.

Agaricales↗
PubMed1985

Vascular responsiveness of isolated, perfused basilar arteries in dogs and monkeys.

A new model of isolated basilar arterial preparation was developed in the dog and monkey. Isolated arteries were perfused at a constant flow rate with Krebs solution and suspended in a bath at 37 degrees C. By inserting the steel cannula into the artery, the space between the luminal wall of the artery and the cannula was narrowed enough to obtain a suitable perfusion pressure during the perfusion. The resting perfusion pressure was maintained at a constant level of 50-100 mmHg. The drug solution was intraluminally administered, and the response was obtained as changes in the perfusion pressure. Responses to 6 vasoactive substances (norepinephrine, 5-HT, PGF2 alpha, histamine, ATP and KCl) were compared between simian and canine basilar arteries. It was demonstrated that in simian arteries, PGF2 alpha was the strongest but 5-HT and norepinephrine induced slight vasoconstriction to the same degree, and in canine basilar arteries, 5-HT induced the strongest constriction but norepinephrine did not produce significant vasoconstriction, and KCl induced marked constriction to the same degree at extremely large doses in both species. It was demonstrated that the cannula inserting method is useful to observe the responses of isolated basilar arteries.

Adenosine Triphosphate↗
PubMed1985

Synthesis and antibacterial activity of 6315-S, a new member of the oxacephem antibiotic.

The synthesis and in vitro activity of 7 beta-difluoromethylthioacetamido-7 alpha-methoxy-3-[[1-(hydroxyethyl)-1H- tetrazol-5-yl]thiomethyl]-1-oxa-3-cephem-4-carboxylic acid sodium salt, 6315-S, are described. 6315-S shows good antibacterial activity against Gram-positive and Gram-negative bacteria, being especially highly active against clinical isolates of Staphylococcus aureus resistant to either ampicillin or methicillin. The structure-activity relationship of related 1-oxa and 1-thia cephems is also presented.

Bacteria↗
PubMed1985

[Systemic blood pressure and respiration during plateau wave phenomena].

The intracranial pressure, systemic blood pressure, respiratory pattern and heart rate were studied polygraphically in five patients with plateau waves in continuous intracranial pressure recording. Three brain-tumor patients and two benign intracranial hypertension patients were included. The intracranial pressure was recorded through an indwelling ventricular catheter attached to a pressure transducer. The systemic blood pressure was recorded through an intraarterial catheter placed in the femoral artery. The recordings were made from 18 to 40 hours and a total of 770 plateau waves were examined in this study. The systemic blood pressure showed little or no change in spite of a marked rise in intracranial pressure. The respiratory alterations were always noted during the plateau waves. This respiratory changes during the plateau waves were assigned into three patterns. The first was the suppressed respiratory pattern during the entire course of the plateau waves (Type I): the second was the pattern characterized by the initial suppression followed by the late hyperventilation (Type II); and the third was the hyperventilation pattern during the entire course of the plateau waves (Type III). The pattern of Type I was noticed in 65% of the observed plateau waves, the pattern of Type II in 23%, and the pattern of Type III in 12%. The heart rate decreased in most plateau waves, but there was little change in the heart rate in some plateau waves.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Intraoperative visualization of coronary arteries using two-dimensional echocardiography].

We attempted intraoperative ultrasonic visualization of the coronary arteries of animal models and of patients who underwent coronary artery bypass surgery. Ultrasonic visualization of coronary vessels using a high frequency wide band micro-transducer (3.5-9.0 MHz) was first attempted in three open-chest dogs. The coronary arteries were well visualized from the epicardium with and without contrast perfusion, and the experimentally-occluded portion was well imaged. Subsequently, this technique was clinically applied in two patients undergoing cardiac surgery for valvular and congenital heart diseases, and in nine patients undergoing coronary artery bypass surgery. Gas-sterilized probes were placed directly over the cardiac surface. Ultrasonic imaging of the coronary artery was performed to detect the coronary arteries beneath the fat tissue; image the lesions in coronary vessels, especially those not visualized by angiography; determine the site of bypass grafting and evaluate the graft-ability to the distal branch (the latter was poorly visualized via collateral circulation or not visualized angiographically because of total occlusion at a proximal site); and observe the effects of bypass grafting and intraoperative angioplasty of coronary arteries after these procedures. This ultrasonic technique was found to be useful for the intraoperative evaluation of coronary vessels for coronary artery bypass surgery.

Animals↗