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Elevation of the mean arterial blood pressure to approximately 150 mmHg by infusion of angiotensin II resulted in an approximate 5.7-fold selective increase in blood flow in tumor tissue without increasing blood flow in normal tissue. This finding of no autoregulation of blood flow in tumor tissue was made in an experiment on inbred DONRYU rats with sc(More)
For further elucidation of the microhemodynamics in tumor tissue, the "vascular level," percentage of the vascular area to tissue area, was measured in DONRYU rats. Changes in the vascular level due to angiotensin II were analyzed by a point-counting method in normal and tumor tissues within a rat transparent chamber. The vascular level in normal subcutis(More)
After a 3-day exposure to 0.1 microM 1-beta-D-arabinofuranosylcytosine (ara-C) in culture, growth was inhibited to 5.6% in MOLT-4F, 25% in Raji, and 91% in Daudi cells compared with control. Growth inhibition was more profound when exposure time was extended up to 7 days. Inhibition of DNA synthesis varied with sensitivity to ara-C. Plateau levels of(More)
Oolong tea extract (OTE) and the purified polymeric polyphenols from OTE have been found to inhibit glucosyltransferase (GTase) of mutans streptococci. In view of the partial fermentation characteristic of oolong tea, we describe here an in vitro model reaction system to produce partially fermented products of D-(+)-catechin or green tea extract (GTE) using(More)
This experiment was carried out to elucidate how tumor microcirculation differs from that of normal tissues. Pressure-flow relationship was examined in normal rat tissues, uninvolved tissues in tumor-bearing rats, transplanted AH109A solid tumors, and primary tumors induced by 3-methylcholanthrene. Tumor blood flow was measured by the hydrogen clearance(More)
Change in beta-glucuronidase activity of six Yoshida ascites hepatomas was examined after treatment of host rats with one of 12 anticancer agents. The hepatomas, AH-66F, AH-130, AH-109A, AH-60C, and AH-44, in decreasing order showed more or less distinct increase in beta-glucuronidase activity after treatment of the rats with Nitromin, Endoxan, 864-T,(More)
On the basis of the observation that the tumor tissue blood flow selectively increases under angiotensin (AT)-induced hypertension, the change of the drug concentration in the tumor and normal tissues was examined in male Donryu rats. The intratumor concentration of fluorescein isothiocyanate-labeled neocarzinostatin was about 2-fold higher in the(More)
The biochemical basis for natural resistance to 1-beta-D-arabinofuranosylcytosine (ara-C) was investigated in the intact cells of 4 rat ascites hepatomas, AH-66F, AH-60C, AH-109A, and AH-66, whose sensitivity to ara-C was different in that decreasing order. The initial rapid uptake of ara-C, mediated by the facilitated diffusion, was similar in all the cell(More)
In order to elucidate further the mechanisms of central necrosis formation and drug delivery into tumor tissue, the interstitial fluid pressure in the normal subcutis and in rat ascites hepatoma AH109A and AH272 tumors was measured by means of a modified diffusion chamber technique. Using our apparatus for determining tissue pressures, we can obtain an(More)