Biomedical subjects
Publications and source records attributed to K Sakaguchi.
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In 19 patients with anteroseptal myocardial infarction, the wall motion of interventricular septum was analyzed by RI angiography using the amplitude image and the phase image. Both images were obtained from ECG gated blood pool data by Fourier analysis. Namely, from the first harmonic in the Fourier series, the heart motion was detected as the amplitude and phase of time-activity curve in each pixel. The distribution of the amplitudes and phases were displayed in color scale, and then both the amplitude and phase images were acquired. Those images allowed us visualization of the ischemic area, even if the scar was parallel to the detector. Moreover, we were able to assess the wall motion of the entire interventricular septum and to distinguish hypokinetic region and dyskinetic region from the hypokinetic region with shift of phase estimated by conventional method. Abnormal region detected by those images closely corresponded with the region of decreased radioisotope concentration in thallium-201 myocardial scintigram.
ECG gated cardiac computed tomography (cardiac (T) was performed in 9 cases with old myocardial infarction. Seven of these had anterio-septal infarction, one had inferior wall infarction and the remaining one had posterior wall infarction. All were investigated by left ventriculography and coronary arteriography. Cardiac CT was performed after intravenous administration of contrast medium usually given as a bolus injection. The infarcted myocardium was thin and showed abnormal wall motion in cardiac CT, but the motion did not always coincide with left ventricular cineangiographic findings. In 3 cases, mural thrombi at the left ventricular apex were observed by cardiac CT, and in 2 of which the thrombi were confirmed by left ventriculography. In 2 cases, cardiac CT showed stasis of contrast medium and aneurysmal formation in the left ventricular cavity and the aneurysms were confirmed by left ventriculography. Sequential 8 mm thick non-ECG gated cardiac CT scans from the cardiac apex to the base were performed in 7 cases with anterio-septal infarction, and the infarcted area were observed in the anterior interventricular septum in 6 cases. We concluded that cardiac CT was a useful noninvasive method to detect abnormal wall motion, abnormally thin wall, mural thrombus and left ventricular aneurysm in old myocardial infarction.
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Twenty-four patients with maxillary squamous cell carcinoma were treated with 50 micrograms of phytohemagglutinin (PHA), saturated into pieces of gelatin sponge, and applied to the maxillary sinus which was in advance surgically exposed via the peroral route. Treatment was combined with cobalt 60 irradiation at 4,000 rads (200 rads X 20 doses over a one month period) and concurrent arterial infusion of 5-fluorouracil (5-FU) with a total dosage of 5,000 mg (250 mg X 20 doses). After 20 treatment with phytohemagglutinin, gross examination showed that tumors were no longer apparent in 83.3% of the cases treated with PHA vs. 52.6% in the control group without PHA. On histological examination, 66.6% in the PHA group showed no signs of tumors vs. 15.8% in the control group. Microscopically, the disappearance of the tumors was frequently observed in tumor of T2 more than that of T3 in extent of primary tumor. No side effects were observed nor was there a significant difference between the control group and the PHA group in the 3-year crude survival rate (control group: 68.4%; PHA group: 62.5%).
A composite plasmid pLS253 was constructed from pLS103 [carrying the Bacillus subtilis leucine genes on B. subtilis (natto) plasmid pLS28] and pHV14 [a recombinant plasmid composed of pBR322 and the staphylococcal R-plasmid pC194] employing BamHI endonuclease, T4 DNA ligase, and B. subtilis transformation. All the Leu+ Cmr transformants tested harbored not only pLS253 but also two smaller plasmids designated as pLS251 and pLS252. pLS253 DNA, when purified on an agarose gel, retained both Leu+ and Cmr transforming activities; however, in all the Leu+ Cmr transformants, the two smaller plasmids reappeared. pLS251 and pLS252 exhibited Leu+- or Cm4-transforming activity, respectively, and must have been derived from the pLS253 parent by an intramolecular recombination event, since the sum of the pLS251 and pLS252 DNAs represent the entire pLS253 genome. The recombination occurred between specific sites on the B. subtilis (natto) and Staphylococcus aureus plasmids. When the composite plasmid, pLS254, was constructed by BamHI cleavage of pLS251 and pLS252 followed by ligation, Leu+ Cmr transformants segregated two smaller plasmids which were indistinguishable from the original plasmids pLS103 and pHV14, respectively. They must have been derived from pLS254 through a reversal of the original recombination event. No intermolecular recombination between pLS251 and pLS252 DNA was detected. The recombination process was independent of recE function of the host cells, and its mechanism is discussed.
A pBR322-T. leu hybrid plasmid was constructed which contains a 3.75 Md HindIII-fragment derived from Thermus thermophilus HB27 chromosomal DNA. In the Escherichia coli host, this plasmid coded for the beta-IPM dehydrogenase (product of leuB) activity, the optimal temperature of which was 80 degrees C, suggesting that information on the thermostability of the enzyme lies in its structural gene. 10-day propagation of E. coli [pBR322-T.leu] at 37 degrees C decreased the temperature optimum from 80 degrees to 75 degrees C. This change, which was found to depend on the plasmid but not on the host cells, might be due to selection of some mutation at the non-restrictive temperature of 37 degrees C. Our results suggest that the 3.75 Md HindIII-fragment of pBR322-T.leu carries a promoter of the thermophile, which could function in E. coli.
The effects of benzaldehyde, which has been found in figs as a carcinostatic element, were studied on the uptake of nucleosides, 2-deoxy-D-glucose, and amino acids into simian virus 40-transformed rat fibroblast cells (SV40-transformed cells) and into the parent normal cells (normal cells). Benzaldehyde, at the concentrations of 25 to 100 microgram/ml at which the selective growth inhibition against SV40-transformed cells was revealed, markedly inhibited the uptake of thymidine, other nucleosides, and 2-deoxy-D-glucose into SV40-transformed cells without any significant inhibition of the uptake of these compounds into normal cells. The uptake of amino acids into both transformed and normal cells was not inhibited by benzaldehyde. Selectively cytotoxic benzaldehyde-related compounds such as 4-nitrobenzaldehyde, 4-acetaminobenzaldehyde, thiophene-3-carboxaldehyde, etc., showed a similar inhibitory effect on thymidine uptake. The deprivation of glucose from the incubation medium strikingly diminished the inhibitory effect of benzaldehyde on the uptake of thymidine and 2-deoxy-D-glucose into SV40-transformed cells. The intracellular adenosine 5'-triphosphate level of SV40-transformed cells was reduced to less than one-half by treatment with benzaldehyde (50 microgram/ml) in glucose-containing medium. This effect was not observed in glucose-free medium. Treatment with benzaldehyde caused no change of the intracellular adenosine 5'-triphosphate level of normal cells. Based on the above results, the selective cytotoxicity of benzaldehyde was attributed to the reduction of intracellular adenosine 5'-triphosphate level of transformed cells, accompanied by the poor uptake of thymidine, glucose, etc., into SV40-transformed cells.
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