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Biomedical subjects

T Ichikawa

Publications and source records attributed to T Ichikawa.

At least 559 records · Page 31Linked to original sources
PubMed1985

Effect of dietary taurine on cholesterol gallstone formation and tissue cholesterol contents in mice.

The inhibitory effect of dietary taurine on cholesterol gallstone formation was studied using male mice of Jcl:ICR strain. Mice were provided three kinds of semi-purified diet; a cholesterol-free diet (standard), a lithogenic diet containing 0.5% cholesterol and 0.25% sodium cholate (C-CA), and a lithogenic diet supplemented with 5% taurine. The changes of total cholesterol in serum, cholesterol mass in the liver and the gall bladder, and gallstone incidence were studied as a function of time. Gallstone formation was observed only in the mice fed on the C-CA diet for more than 3 weeks. The changes of serum cholesterol concentration were not consistent with gallstone formation. The cholesterol mass of the liver in taurine-supplemented mice decreased after the 3rd week. Cholesterol content of the gall bladder increased with cholesterol gallstone formation. Therefore, the inhibitory effect of dietary taurine on cholesterol gallstone formation may be related to the decrease in cholesterol content of the liver.

Animals↗
PubMed1985

[Quantitative analysis of aortic regurgitation using radionuclide phase analysis].

In this study, the clinical utility of phase analysis using gated blood pool scintigraphy to detect aortic regurgitation (AR) was assessed. The study population included 33 patients with AR documented by cineaortography, and 53 patients without AR diagnosed by clinical features and pulsed Doppler echocardiography or cineaortography. Gated blood pool images were stored in modified left anterior oblique views by the multiple gated method (28 frames per beat) after the in vivo labeling of erythrocytes using 25 mCi 99m-Tc. Amplitude was depressed at the subaortic region toward the apex in patients with AR, and occasionally the phase angle occurred earlier in the same region. This is because diastolic filling began earlier and stroke count was decreased more in the subaortic region than in other regions of the left ventricle in examining the regional time-activity curve. Based on this characteristic finding in the amplitude image, the specificity was 81% and the sensitivity was 79% in the diagnosis of AR. The degree of AR was estimated using the amplitude image as follows: grade 1, depression of amplitude localized to the subaortic region; grade 2, depression of amplitude detected from the subaortic region to the midportion of the left ventricle; grade 3, depression of amplitude detected beyond the midportion of the left ventricle. We compared results with those of the radionuclide (RI's classification) and angiographic methods (Sellers' classification) as to the severity of AR. AR could not be detected using the radionuclide method in all four patients with Sellers' grade 1, and in three of nine patients with Sellers' grade 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Insufficiency↗
PubMed1985

[Detection of thrombi by 111In-oxine platelet scintigraphy].

For 52 patients with cardiac disease and 11 patients with vascular disease, In-111-oxine platelet scintigraphy was performed to assess its clinical usefulness for detecting thrombi. Using Hayashida's method, platelets were separated in 43 ml peripheral blood, washed and labeled with 1 mCi In-111-oxine. In addition to planar images in the anterior, 45 degrees left anterior oblique and left lateral views, single photon emission computed tomography (SPECT) was performed in some cases by rotating a dual gamma camera 24 and 72 hours after labeled platelet injection. The functions of platelet and coagulability were examined 36 hours after the injection of labeled platelets. Medical therapy was not changed during this study. Intracardiac thrombi were documented in 16 of 52 cases with cardiac disease and intravascular thrombi in 10 cases with vascular disease by angiography, CT and two-dimensional echocardiography. Positive images were obtained in 10 cases with cardiac disease and in eight cases with vascular disease by scintigraphy. Therefore, sensitivity, specificity, and overall accuracy were 63%, 100% and 88% in intracardiac thrombi; 80%, 100% and 82% in intravascular thrombi; and totally 69%, 100% and 87%, respectively. In the detection of intracardiac thrombi by scintigraphy, the sensitivity seemed to be lower and the specificity higher than those by other graphic studies. In 52 cases with cardiac disease, five out of six cases with false negative images had received antiplatelet and/or anticoagulant drugs, and in these cases, platelet and coagulation functions tended to be decreased compared with those of true positive cases or true negative cases. We conclude that positive images in scintigraphy indicate the existence of growing thrombi, and that In-111-oxine platelet scintigraphy has clinical usefulness, not only for detecting thrombi, but for estimating platelet activity and effect of medical therapy.

Blood Platelets↗
PubMed1985

[Clinical studies of bestatin on genitourinary cancer].

Bestatin was administered to 20 patients with urogenital tumors. The therapeutic results showed 12 surviving patients and 8 dead patients (including 7 due to cancer and 1 due to a cerebrovascular disorder). One patient has survived for 5 years since bestatin treatment of pulmonary metastasis of renal cancer, and one other patient achieved 5-year survival in spite of systemic metastases of testicular tumor. It is noteworthy that in earlier times these patients could have been expected to experience sudden relapse and aggravation, instead of the long-term survival recorded in this bestatin trial. Studies were conducted on the immunological parameters of the patients before and after the use of bestatin, and it was found that these parameters showed improvement as a result of the treatment. Even though bestatin was ingested for long periods of time by these patients, there was almost no development of adverse reactions to the treatment.

Adjuvants, Immunologic↗
PubMed1984

Termination profiles of photoreceptor cells in the larval eye of the swallowtail butterfly.

Profiles of the axonal endings of seven retinular cells (R1-7) from each of six stemmata (I-VI) of the butterfly Papilio xuthus were examined. Their axons enter the brain anteroventrally and project dorsally along the brain's lateral surface before entering the optic neuropil. Larval optic neuropil has two distinct areas, a (distal) lamina and a (proximal) medulla, connected by a chiasma. Intracellular administration of cobalt shows that distal retinular cells (R1-3 of stemmata I-IV, R1-3 and R6 of stemmata V and VI) terminate as short axons with plug or toothbrush-like endings in the lamina. Proximal retinular cells (R4-7 of stemmata I-IV, R4, R5 and R7 of stemmata V and VI) terminate as long axons in the chiasma or in the medulla. The long axons have fine branches in the lamina, chiasma and medulla. The two proximal cells (R5 and R7) are distinguished by their deeper endings and longer branches. The terminals of photoreceptors correspond to their photoreceptive properties and provide further evidence for the functional specialization of the photoreceptors.

Animals↗
PubMed1984

Intercellular junctions in odontoblasts of the rat incisor studied with freeze-fracture.

The morphology and distribution of various types of intercellular junctions were investigated in young odontoblasts. Gap junctions were found between odontoblasts as well as between odontoblasts and fibroblasts in the dental pulp. The junctions between odontoblasts were larger and more numerous than those between odontoblast and fibroblast, suggesting that the former may play an important role in regulating cellular activity and the latter may provide a pathway of low electrical resistance between odontoblast and nerve fibres. Irregularly-shaped gap junctions appeared as small aggregations of particles associated with a particle-free area and may indicate that the junction might not yet have been completely assembled. Tight junctions were observed at the distal ends of the young odontoblasts, arranged to form small maculae or faciae occludentes rather than belt-like zonulae. It is therefore not likely that the junction contributes to barrier function in the young odontoblasts. Although structures resembling typical desmosome were recognizable, this type of junction in odontoblasts is properly termed a desmosome-like junction from its morphological peculiarities.

Animals↗
PubMed1984

Primary structures of multiple forms of urotensin II in the urophysis of the carp, Cyprinus carpio.

Multiple forms of urotensin II (UII), one of the hormonal peptides of the caudal neurosecretory system of fishes, were purified from the urophyses of the carp, Cyprinus carpio. Three distinct peaks with UII activity (classified as UII-alpha, -beta and -gamma) were separated by reverse-phase high-pressure liquid chromatography (HPLC). Edman degradation as well as digestion with carboxypeptidase A revealed the primary structures of these peptides as UII-alpha: Gly-Gly-Gly-Ala-Asp-Cys-Phe-Trp-Lys-Tyr-Cys-Val UII-beta: Gly-Gly-Ser-Asn-Thr-Glu-Cys-Phe-Trp-Lys-Tyr-Cys-Val UII-gamma: Gly-Gly-Gly-Ala-Asp-Cys-Phe-Trp-Lys-Tyr-Cys-Ile The results of thin-layer chromatography, HPLC, amino acid analysis, and sequencing indicate that UII-alpha and -gamma are homogeneous. UII-beta appears, however, to be a mixture of two components, differing only at position 2. Thus, in the carp urophysis, four forms of UII appear to be present, although the separation of two components in UII-beta has not been obtained. Sequence of positions 6-11 is common to all forms of UII isolated from the carp, sucker (Catostomus commersoni) and goby (Gillichthys mirabilis).

Amino Acid Sequence↗
PubMed1984

Occurrence of galactosamine-6-phosphate as a constituent of Bacillus megaterium spore coat.

Galactosamine-6-phosphate was identified as a component of the coat of the Bacillus megaterium QM B1551 spore. It was one of the main constituents of the outermost layer of the spore coat, but it was absent from the other integuments including the cortex. These findings suggest that galactosamine-6-phosphate comprises the phosphorus-containing skeleton structure of the spore coat.

Bacillus megaterium↗
PubMed1984

Clinical trial of the Oka strain of live attenuated varicella vaccine on healthy children.

Clinical and serological follow-up studies were made on 257 healthy children who had received live varicella vaccine (strain Oka) in Showa Hospital. Good antibody responses were shown with a seroconversion rate of 98.4% (253/257) by the immune adherence hemagglutination test. Mild adverse reactions were observed in 11 of the vaccinated children. During observation periods of 6 months to 4 years, 6 of the 253 children who were successfully vaccinated contracted mild varicella, while all 4 vaccinees who showed no primary immune response contracted mild to moderate clinical varicella. It is concluded that this vaccine is highly immunogenic and causes few clinical reactions in normal children.

Adolescent↗