Search PubMed⌕ Search

Biomedical subjects

T Iba

Publications and source records attributed to T Iba.

29 records · Page 2Linked to original sources
PubMed1992

[A case of gallbladder cancer with marked response to EAP treatment].

A case of unresectable gall bladder cancer due to multiple metastasis was dealt with EAP (VP-16, ADM, CDDP) treatment. The case was a 49-year-old male who was admitted to the hospital with a 3 cm sized umbilical tumor. After 2 cycles of the treatment, the tumor size significantly decreased and the symptoms diminished. In parallel, the symptoms from bone metastasis and dissemination also disappeared. As for tumor markers, CA 19-9 indicated 5151 U/ml, fell down to the normal range after the treatment. In this case, the efficacy of EAP treatment to the primary gall bladder carcinoma was undetectable, because of the difficulty of elucidation of the primary site by diagnostic images. However, all data suggested that EAP treatment was effective to the advanced unresectable gallbladder cancer, at least to its metastatic sites.

Adenocarcinoma↗
PubMed1991

Stimulation of endothelial secretion of tissue-type plasminogen activator by repetitive stretch.

Endothelial cells (EC) synthesize many of the fibrinolytic components and anticoagulants present in plasma. EC have been demonstrated to release tissue type plasminogen activator (t-PA) and its rapid inhibitor type 1 plasminogen activator inhibitor (PAI-1). In vivo, EC lining a blood vessel are exposed to the forces of the circulation, predominantly shear stress and pulsatile stretch. We have previously reported that repetitive stretch of EC in culture will stimulate prostacyclin secretion. In this study, the effects of cyclic stretch on the production of t-PA and PAI-1 by cultured EC were examined. EC harvested from human saphenous vein were seeded in culture plates with flexible membrane bottoms and grown to confluence. Vacuum (-20 kPa) was used to deform the membrane bottoms to 24% maximum strain. EC in the experimental group were subjected to 24% maximum strain at 60 cycles/min (0.5 sec elongation alternating with 0.5 sec relaxation), while control EC were grown on the same membranes but kept stationary in the same incubator. After 1, 3, and 5 days, the cell numbers were counted and the media were collected and analyzed for t-PA and PAI-1 by ELISA. The result shows a significant increase in t-PA production with the cyclic stretch on Days 3 and 5. There was no significant difference in PAI-1 levels in stretched versus stationary EC. We concluded that cyclic stretch of EC in vitro can selectively stimulate t-PA production and may account for the relative nonthrombogenicity of the endothelium in vivo.

Cells, Cultured↗
PubMed1991

Morphological response of human endothelial cells subjected to cyclic strain in vitro.

Endothelial cells (EC) are subjected to hemodynamic forces in vivo. However, most in vitro studies of EC biology have been performed utilizing stationary culture conditions. To study the morphology and cytoskeletal features of EC under dynamic culture conditions, we utilize a system capable of exerting repetitive strain on cells in culture. Human saphenous vein EC were plated to a subconfluent density in 25-mm wells with a thin flexible bottom and a rat collagen, Type I surface. A -20 kPascals vacuum applied to the bottoms led to a maximum deformation of 24%. EC were exposed to 0.5 sec deformation alternating with 0.5 sec relaxation (60 cycles/min) for 24 hr. EC were fixed with formalin at different time intervals and stained with crystal violet. Actin filaments were stained with rhodamine phalloidin, an F-actin marker, while beta-tubulin and vimentin were visualized by immunofluorescent antibody techniques. Within 15 min after initiation of cyclic strain, actin stress fibers were aligned perpendicular to the force vector. By 12 hr of cyclic strain EC were elongated and oriented in the same direction as the actin filaments. EC elongation and alignment were inhibited by cytochalasin B. Even up to 24 hr of cyclic strain, beta-tubulin and vimentin distributions were unaltered. We propose that cyclic strain of EC in vitro influences cell alignment and elongation by a mechanism dependent on the actin filament system.

Cells, Cultured↗
PubMed1991

Effect of cyclic stretch on endothelial cells from different vascular beds.

Endothelial cells (EC) mediate many of the organ responses to shock. Much of our knowledge of EC are obtained from cell culture studies. However, compared to the dynamic milieu in vivo, the stationary environment for large-vessel EC may be artificial and inappropriate. In this study, the morphology, growth rate, and production of prostacyclin (PGI2) by EC obtained from different vascular beds under stationary and dynamic conditions were examined. EC were harvested from the thoracic aorta (Ao), pulmonary artery (PA), and vena cava (VC) of the same calves and exposed to 0.5 sec 24% deformation alternating with 0.5 sec relaxation (i.e., 60 cycles/min). Our results show that in response to the cyclic regimen, VCEC were elongated perpendicular to the force vector and their actin filaments aligned in the same direction, while AoEC and PAEC did not exhibit any morphological changes. The growth rate of AoEC (but not PAEC or VCEC) was significantly enhanced when stimulated by cyclic stretch. In addition, AoEC demonstrated an increased PGI2 synthetic activity with cyclic stretch, while PAEC and VCEC were unaltered. We conclude that the maintenance of EC phenotype and function is dependent on the hemodynamic milieu in vivo and may be influenced by the vascular origin of the cultured EC.

Animals↗
PubMed1990

Modulation of endothelial cell phenotype by cyclic stretch: inhibition of collagen production.

Endothelial cells (EC) are constantly subjected to pulsatile stretch in vivo, but most studies of EC are performed under stationary tissue culture conditions. The aim of this study was to examine the effect of repetitive mechanical stretching on EC collagen production. Bovine EC were seeded in 35-mm flexible-bottom culture wells, allowed to attach for 24 hr, and then subjected to up to 24% elongation cyclic deformation, 3 cycles/min, 10 sec of elongation alternating with 10 sec of relaxation, for 5 days. Twenty-four hours prior to harvesting, serum-free media containing 50 microCi [3H]proline (PRO), an amino acid hydroxylated (OH) in collagen, and 50 micrograms/ml ascorbate were added per well. On Days 1, 3, and 5, the media and cells were collected, precipitated with TCA, sedimented, lyophilized, and analyzed by HPLC for OH-PRO and PRO. The results of this study indicate that EC production of collagen is inhibited with repetitive deformation. Since previous studies have shown that EC proliferation is increased after 3 cycles/min stretching, this supports the theory that collagen gene expression varies inversely with the proliferative state.

Animals↗
PubMed1990

Determination of specific activity of cobalt (60Co/Co) in steel samples exposed to the atomic bomb in Hiroshima.

Specific activity 60Co/Co in two steel samples taken at 687m S and 1295m NNW from the hypocenter was measured by gamma-ray spectrometry and neutron activation analysis. The results were, respectively, (2.64 +/- 0.38) x 10(1) and (3.09 +/- 0.48) x 10(-1) dpm/mg Co at the time of bombing, which are consistent with previous data by Hashizume et al. for steel rings on the surface of roofs of buildings. The present data are expected to serve as verification of the bomb neutron transport calculations. Content of nickel and copper in the samples, determined by colorimetric and neutron activation methods, respectively, was too small to account for any significant 60Co production by the (n,p) and (n, alpha) reactions.

Cobalt Radioisotopes↗
PubMed1989

[Reliability of the lipid emulsion test for reticuloendothelial system].

The reticuloendothelial system is important as one of the self defense mechanisms. We performed two investigations to confirm the reliability of the lipid emulsion test for determining the reticuloendothelial system function. 1) The lipid emulsion serum clearance was contrasted with the counts of lipid emulsions phagocytosed by Kupffer cells in liver. 2) Lipid emulsion clearance was contrasted with the hepatic uptake rate of 99mTc-phytate. The result demonstrated a positive correlation among lipid emulsion clearance, the counts of lipid emulsions phagocytosed by Kupffer cells and the hepatic uptake rate of 99mTc-phytate. These results confirm that the lipid emulsion test is sufficient to reflect Reticuloendothelial system function.

Adult↗
PubMedDate not supplied

Development of ultra-high sensitivity bioluminescent enzyme immunoassay for prostate-specific antigen (PSA) using firefly luciferase.

A bioluminescent enzyme immunoassay (BLEIA) for prostate-specific antigen (PSA) using biotinylated firefly luciferase-labelled antibody was developed. PSA is an important marker for the diagnosis and management of prostate cancer. Our BLEIA for PSA, based on the two-step sandwich method, had ultra-high sensitivity and a very wide measurable range. The detection limit (mean of nine replicates of the zero standard +2 SD) for PSA was 0.25 pg/mL and the measurable range for PSA was 0.25 pg/mL-100 ng/mL. Generally, PSA in the serum exists on two forms, called free PSA (f-PSA) and complex PSA (c-PSA), which is formed with alpha-antichymotripsin. Thus, the response of the PSA assay to these two forms has to be equimolar in the construction of the assay system. Our BLEIA for PSA also had an equimolar response to them.

Animals↗