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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 577 records · Page 32Linked to original sources
PubMed1983

[Application of PIXE (particle-induced x-ray emission) method to the cytolytic test of tumor cells].

Immunological studies have often been based on the results of cytolytic assay in which cells labelled with radioactive 51Cr are usually employed. The replacement of the radioactive isotope by a stable one is obviously desirable in order to eliminate the problem of radiation hazard and to prevent environmental contamination. We applied PIXE (particle induced X-ray emission) method for the detection of stable chromium (Cr). MM46 cells labelled with natural Cr were treated with anti-MM46 serum and a rabbit complement. The remaining Cr was filtered. The released Cr was precipitated with ethanol and deposited on the filter. The specimens were bombarded with proton beams from a Van de Graaff accelerator and the X-rays produced were detected with a Si(Li) detector. The Cr peaks appeared clearly. One of the main advantages of the application of the PIXE method is its high sensitivity. Another merit of the present method is that it can easily compare the remaining ratio of several elements in cellular materials after lytic treatment. This information may be used as a parameter indicating differences in the process of cytolysis.

Animals↗
PubMed1983

[Evaluation of Hancock mitral valve by M-mode echocardiography. Clinical significance of the timing of closing and opening of the valve].

The valve function of a Hancock xenograft in the mitral position was evaluated by M-mode echocardiograms guided by the two-dimensional echocardiogram. From M-mode echocardiograms, the intervals from the second heart sound to mitral valve opening (II-MVo) and from the Q wave to mitral valve closure (Q-MVc) were measured in 24 patients with a Hancock xenograft, 16 with mitral stenosis (MS) and 20 normal controls. Twenty-four patients with a Hancock xenograft were divided into four groups according to the echocardiographic pattern of the xenograft. Fourteen with normal echocardiograms (I: N.P.), five with delayed opening of cusps from 20 to 90 msec (II: D.O.), three with a coarse fluttering of cusps in diastole (III: D.F.), and two with an obstructed prosthesis (IV: O.P.). The valve function of groups II and III was clinically normal. This suggests that a coarse fluttering of cusps and delayed opening of cusps do not always indicate malfunction of the Hancock xenograft. M-mode echocardiograms of group IV showed an increased thickening of cusps, multiple dense echoes between valve stents and a lack of a clear E point. The beat-to-beat variations of Q-MVc and II-MVo intervals showed no significant differences among patients with the Hancock xenograft, MS and normal controls. A small time-dependent variation of Q-MVc and II-MVo intervals observed in patients with the Hancock xenograft did not seem to interfere the reliable reproducibility of these intervals. In group I, II-MVo interval was 104 +/- 8 msec (mean +/- S.E.), which was significantly longer than that of normal controls (54.5 +/- 2.5 msec) (p less than 0.005). In groups II and III, II-MVo interval was almost equal to that of group I, but in two of group IV, this interval was 20 and 30 msec, respectively which was markedly shortened. Q-MVc intervals did not show significant differences among groups I, II, III and IV. There were significant differences in Q-MVc interval among patients with MS and the Hancock xenograft and normal controls. II-MVo interval of group I was inversely correlated with mean diastolic posterior wall velocity (MDPWV), stroke index (SI) and delta ejection time (ET), but significantly correlated with delta preejection period (PEP) and PEP/ET. However, there was no significant relationship between II-MVo interval and pulmonary capillary wedge pressure. This suggested that prolonged II-MVo interval reflects postoperative left ventricular dysfunction. In conclusion, to evaluate the function of a Hancock xenograft, echocardiograms of valve cusps and measurement of II-MVo interval have useful clinical significance.

Bioprosthesis↗
PubMed1983

[Computed tomography of suprasellar cystic lesions].

Difficulties are often encountered in the differential diagnosis of suprasellar cystic lesions in computed tomography (CT). During the past 5 years and 7 months we experienced 22 such cases. In this report we tried to review the characteristic CT findings for the differential diagnosis of these lesions. Population of this study is consisted by 7 pituitary adenomas (4 non-functioning adenomas, 2 prolactinomas and 1 GH-secreting adenoma), 8 craniopharyngiomas, 4 arachnoid cysts and 3 Rathke's cleft cysts. In cases of pituitary adenomas and craniopharyngiomas, we included only those cases which were found to be completely cystic. Each case was scanned before and after contrast material injection and in majority of cases coronal scans were also obtained after contrast injection. The analysis was based on the CT appearance of the shape, the content and the wall of each cyst. The wall of the cyst was evaluated according to its thickness, density, presence of calcification and contrast enhancement. In 14 out of 22 cases the X-ray attenuation values of their content were calculated after setting the ROI in the cyst on the CT display console. Craniopharyngioma often showed calcification in its wall, which was not seen in the wall of pituitary adenoma. The wall of pituitary adenoma revealed contrast enhancement in all cases, but half of craniopharyngioma showed no contrast enhancement in its wall. These two points are useful for the differential diagnosis of these lesions which we encounter most frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1983

[Primula dermatitis].

Ten patients with primula dermatitis observed in Hokkaido were reported. All patients presented positive patch test reactions to a part of an extract of primula obconica. Postlesional pigmentation is prominent in patients with recurrent dermatitis. Histologic features were liquefaction degeneration of a basal layer of the epidermis and incontinentia pigmenti histological, i.e., lichenoid tissue reaction.

Adult↗
PubMed1983

Biliary cystadenocarcinoma diagnosed by liver biopsy performed under ultrasonographic guidance.

A case of a 60-yr-old man with biliary cystadenocarcinoma is reported. By needle biopsy of a cystic lesion performed under ultrasonographic guidance, overt malignant tissue could be obtained successfully. Histologic examination on autopsy material revealed that the tumor arose from preexisting benign liver cysts. The tumor showed a feature of well-differentiated, mucin-producing papillary adenocarcinoma in the primary site while, in the metastatic foci, it produced solid cell clusters with a tendency toward the differentiation into squamous cells.

Biopsy↗
PubMed1982

Virulence of Escherichia coli in ascending urinary-tract infection in mice.

The virulence of Escherichia coli strains in ascending urinary-tract infection was studied in mice drinking a 5% glucose solution; factors determining the virulence were examined. Of 33 strains, 8 (group I) infected the bladder and kidney, 10 (group II) infected only the bladder, while the remaining 15 strains (group III) did not cause infection. The adherence of group-I and group-II strains to bladder epithelial cells in vitro was inhibited by D-mannose. In group III, 13 strains barely adhered to the epithelial cells, while two strains showed an adherence unaffected by D-mannose. Most strains in groups I and II agglutinated erythrocytes of guinea-pig, chicken, and horse, and cells of Candida albicans in a mannose-sensitive manner. All strains in groups I and II had fimbriae. Virulence for the urinary tract was not directly related with O-serotype, intraperitoneal virulence, ability to grow in mouse urine, ability to ferment dulcitol, production of haemolysin, susceptibility to serum bactericidal activity, or susceptibility to antibiotics. These results suggest that the adherence of the E. coli to mouse-bladder epithelial cells in a mannose-sensitive manner plays an important role in the development of urinary-tract infection in mice and that the adherence is probably mediated by type-1 or closely related fimbriae.

Adhesiveness↗
PubMed1982

Characteristics of Protease Production by Cephalosporium sp.

We investigated protease formation by Cephalosporium sp. strain KM388, which produced trypsin inhibitor in the same cultures, in medium containing polypeptone, meat extract, and glucose (natural medium) and in medium containing NaNO(3), glucose, and yeast extract (semisynthetic medium). In natural medium, protease was secreted into the culture broth after cessation of growth caused by consumption of the polypeptone, the growth-limiting substrate. Enzyme formation in the stationary growth phase was due to de novo and so-called preferential synthesis, because cycloheximide immediately inhibited enzyme formation. In semisynthetic medium, protease was produced in parallel with mycelial growth, but production was repressed by the addition of polypeptone to the medium; protease production began after the added polypeptone was consumed. On the other hand, if glucose was eliminated from natural medium, the lag period of initiation of enzyme production was reduced until the late exponential phase. The addition of phosphate up to a concentration of 1.0% to natural medium also shortened the lag period and damped the pH change of the broth during cultivation.

Journal Article↗
PubMed1982

Kinetics of substrate utilization in adenine-limited chemostat cultures of Bacillus subtilis KYA741.

The specific rates of limiting substrate utilization were investigated in adenine- or glucose-limited chemostat cultures of Bacillus subtilis KYA741, an adenine-requiring strain, at 37 degrees C. With the glucose-limited cultures, the specific rate of glucose consumption versus dilution rate gave a linear relationship from which the true growth yield and maintenance coefficient were determined to be 0.09 mg of bacteria per mg of glucose and 0.2 mg of glucose per mg of bacteria per h, respectively. With the adenine-limited cultures, adenine as the limiting substrate was not completely consumed at lower dilution rates (e.g., D less than 0.1), unlike in the glucose-limited cultures. When a linear relationship of specific rate of adenine consumption versus dilution rate was extrapolated to zero dilution rate, a negative value for the specific rate of adenine consumption, -0.01 mg of adenine per mg of bacteria per h, was obtained, giving a true growth yield for adenine of 5.2 mg of bacteria per mg of adenine. On the other hand, the maintenance coefficient of oxygen uptake gave a positive value of 8.1 x 10(-3) mmol/mg of bacteria per h. Based on previous results showing that adenine is resupplied by lysing cells, we developed kinetic models of adenine utilization and cell growth that gave a good estimation of the peculiar behavior of cell growth and adenine utilization in adenine-limited chemostat cultures.

Adenine↗