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T Shibata

Publications and source records attributed to T Shibata.

At least 883 records · Page 49Linked to original sources
PubMed1987

Effect of vitamin E and ticlopidine on platelet aggregation in Fabry's disease.

Thromboembolism, increased platelet aggregation and high plasma concentration of beta-thromboglobulin were observed frequently in hemizygotes and heterozygotes of Fabry's disease. The administration of vitamin E and ticlopidine could improve the increased platelet aggregation in this disease. The platelet activation, probably induced by vascular endothelial damages, would accelerate atherosclerotic and thromboembolic vascular changes. Antiplatelet therapy will be effective for the prevention of these vascular complications in this disease.

Adolescent↗
PubMed1987

Metastatic nodules of hepatocellular carcinoma: detection with angiography, CT, and US.

Accurate detection of intrahepatic metastases, or daughter nodules, of primary hepatocellular carcinoma is of crucial importance. Due to the introduction of infusion hepatic angiography, computed tomography (CT) after Lipiodol (iodized oil) infusion, and intraoperative ultrasound (US), tumors less than 10 mm in diameter are now frequently found. We compared the diagnostic accuracy of these three modalities in the detection of nodules in 45 patients who had hepatocellular carcinoma (confirmed by biopsy). CT with Lipiodol was superior to hepatic angiography in demonstrating nodules when they were overlapped by the primary tumor or very small in size. Intraoperative US demonstrated nodules in four avascular or hypovascular hepatocellular carcinomas, which both hepatic angiography and CT failed to demonstrate. In cases associated with severe liver cirrhosis, differentiation of small nodules from regenerating cirrhotic nodules was sometimes difficult with intraoperative US. The combined use of these three modalities is indispensable for the accurate detection of small nodules of metastatic hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1987

Dynamic stiffness measured in central segment of excised rabbit papillary muscles during barium contracture.

The dynamic mechanical behavior of excised rabbit papillary muscles that had been tonically activated by replacing bathing Ca2+ with Ba2+ was studied. Steady activation was used to visualize the dynamic behavior of cardiac myofilaments more clearly than is possible during twitches, which are complicated by the kinetics of excitation-contraction coupling. To avoid artifacts due to damaged ends of the muscle, the length of a central segment, which was defined by 2 tungsten pins inserted through the muscle, was measured. To test the mechanical behavior of the contractured muscles (at 24 degrees C), the central segment length was sinusoidally oscillated (amplitude 1%) at 15 different frequencies (0.05-30 Hz). The dynamic stiffness of the central segment was calculated from the ratio of force response amplitude to length perturbation amplitude. At low frequencies (below 0.4 Hz), stiffness was approximately constant and reflected the force-length relation. However, in a localized range near 1 Hz, there was a distinct drop in the magnitude of dynamic stiffness to approximately half its low-frequency baseline. This range may reflect the dynamics of attachment and detachment of force generators. The frequency of minimum stiffness was consistent among all muscles (1.3 +/- 0.3 Hz). Moreover, no significant change in this frequency was found over the examined range of lengths (90-100% of the segment length that produced maximal developed force) and activation levels (Ba2+ concentration 0.3-1.0 mM). From 2 to 8 Hz, dynamic stiffness appeared to reflect force-velocity properties, but at higher frequencies, another elastic property emerged. At 30 Hz, stiffness was proportional to force, with an apparent series elasticity less than 1.8%. Even though the muscles had only moderate longitudinal inhomogeneity, quantitatively significant (35%) errors would have been introduced had the study relied on total muscle length instead of central segment length.

Animals↗
PubMed1987

Dynamic stiffness of barium-contractured cardiac muscles with different speeds of contraction.

The dynamic stiffness of excised cardiac muscles that would be likely to have different intrinsic speeds of contraction, as judged by previous biochemical reports of their myosin ATPase rates, was compared. This study included muscles from thyrotoxic rabbits and newborn rabbits, rabbit atria, and normal papillary muscles at different temperatures. The usual excitation-contraction coupling process was bypassed by replacing bathing Ca2+ with Ba2+. The ensuring actively maintained contracture allowed us to focus more specifically on the contractile properties of the myofilaments. Dynamic stiffness was determined by sinusoidally oscillating muscle length at many different frequencies over the range 0.05-50 Hz while holding average muscle length at 95% of the systolic length, thus giving maximal developed force. The form of the stiffness modulus spectrum was similar for all muscles studied: stiffness was fairly constant at low frequencies, decreased to a minimum at an intermediate frequency, and then increased steeply, followed by a milder rate of increase over high frequencies. Differences in contraction speed were evident by shifts in the frequencies at which corresponding portions of the stiffness spectrum appeared. The clearest landmark was the frequency where stiffness became minimum (fmin). This varied strongly with temperature (Q10 = 2.9). Compared to normal adult papillary muscles (fmin = 1.2 Hz), fmin was 2.2 times faster in thyrotoxic myocardium, 1.9 times faster in 1-week-old rabbits, and 3.7 times faster in atrial trabeculae. These ratios of functional speed are similar to the corresponding ratios of myosin Ca2+-ATPase activities reported in the literature.

Animals↗
PubMed1987

Growth rate of human pituitary adenomas.

The immunohistological detection of a proliferation-associated nuclear antigen by the monoclonal antibody Ki-67 allows the determination of the growth fraction in human cell populations. In this study, biopsy specimens of 31 pituitary adenomas representing all major endocrine types were examined. All adenomas contained proliferating cells and the percentage of nuclei that were immunoreactive to Ki-67 ranged from 0.1% to 3.7%. Low values (0.1% to 1.0%) were present in 11 endocrine-inactive adenomas and higher values (1.1% to 1.5%) were found in six acromegalic patients. The percentages of Ki-67-positive cells in 12 prolactinomas and two adenomas from patients with Cushing's disease covered the entire range (0.1% to 3.7%). Preoperative bromocriptine treatment of prolactinomas did not influence Ki-67 expression. Invasive adenomas, as determined by preoperative computerized tomography, surgical observation, and histological examination of the sella dura demonstrated significantly higher Ki-67 values (average 1.15%) than noninvasive adenomas (average 0.60%). Determination of the incidence of proliferating cells by Ki-67 immunoreactivity represents a new tool for intraoperative quantitative assessment of tumor growth characteristics and may aid in the planning of adjuvant therapy and estimation of prognosis.

Adenoma↗
PubMed1987

[Origin of colloid cyst: immunoperoxidase study].

Despite their consistent anatomic location and histological features, the histogenesis of colloid cysts has remained obscure. We report immunohistochemical data on surgically excised cysts in attempt to define the origin of the lining epithelial cells. Paraffin-embedded tissues from colloidal cysts (7 in the 3rd ventricle and one in the sella) and two similar epithelial cysts (one in the cerebellopontine angle and one in the sella) were investigated. After examination by conventional stains, immunoperoxidase studies were carried out using primary antisera against epithelial membrane antigen (EMA), tissue polypeptide antigen (TPA), epidermal keratin (EK) and S-100 protein. The apical plasma membrane, surface microstructures were consistently EMA positive. Columnar cells demonstrated cytoplasmic staining for TPA. Basal cells of lining epithelia expressed EK. All epithelia studied were negative for S-100 protein. These findings suggest an endodermal origin of colloid cysts.

Adult↗
PubMed1987

Collagen and collagenase in ulcer tissue--1. The healing process of acetic acid ulcers in rats.

We have reported that collagenase activity of the gastric mucosa increased significantly in acetic acid ulcers of dogs. The present study revealed that acetic acid ulcers in showed that the active collagenase level in the ulcer tissue increased rapidly with a peak (412.5%) on the 3rd day after induction of the acetic acid ulcer. Thereafter, the collagenase activity levels decreased gradually by the 7th day and returned practically to the control levels by the 14th day. On the other hand, collagen (hydroxyproline content) decreased by the 7th day (-16.5%) and recovered by the 14th day after induction of the acetic acid ulcer. The peak of active collagenase on the 3rd day coincident with the maximum ulcer index, suggesting involvement of collagenase activity in ulceration. In addition, destruction and production of collagen are considered to take place not only at the base of the ulcer and its margin, but also along its circumference.

Acetates↗
PubMed1987

[recA protein].

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Adenosine Triphosphatases↗
PubMed1987

2-Arylidene-4-cyclopentene-1,3-diones designed as non-nitro radiosensitizers and hypoxic cytotoxins.

The radiosensitizing effects and hypoxic cytotoxicity of 2-(4'-hydroxybenzylidene)-cyclopentene-1,3-dione (KIH-200) and its 3'-methoxy and 3',5'-dimethoxy derivatives (KIH-201 and KIH-202) were investigated in vitro. These synthetic compounds were newly designed as non-nitro electron-affinic radiosensitizers and hypoxic cytotoxins on the basis of their high electron affinities and electrostatic potentials which were estimated by semiempirical molecular orbital calculation using the CNDO/2 program. The compounds were shown to have weak but apparent hypoxic cytotoxicity to FM3A cells from C3H mice. On irradiation in the presence of KIH-201 or KIH-202, hypoxic cells were more sensitive than aerobic cells at very low drug concentrations (below 10 microM), whereas KIH-200 was less effective.

Animals↗