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Biomedical subjects

I Ando

Publications and source records attributed to I Ando.

At least 91 records · Page 5Linked to original sources
PubMed1983

[In vivo uptake of Ga-67 citrate by an experimental abscess and the mechanism of Ga-67 uptake].

This study was undertaken to investigate the accumulation of 67Ga in an experimental abscess and to elucidate the mechanism of 67Ga uptake in the abscess. Two, three, five, seven and ten days after subcutaneous injection of 0.2 ml turpentine to the rats, 67Ga-citrate was injected to the rats. Twenty-four hours after injection of 67Ga, abscess and organs were excised and uptake rates of 67Ga were assayed. Furthermore, five days after subcutaneous injection of 0.2 ml turpentine to the rats, 67Ga-citrate was injected to the rats, at various time intervals from 10 minutes to 6 days, abscess and organs were excised and uptake rates of 67Ga were assayed. And subcellular distribution of 67Ga in abscess was determined at various time intervals after administration of 67Ga-citrate. On the other hand, to elucidate 67Ga binding substances in abscess, 67Ga-citrate and sodium sulfate-35S were injected to the above rats, respectively. Twenty-four hours after injection, abscess was excised and homogenized. The homogenate was digested with proteinase. After digestion, the reaction mixture was gel-filtered on Sephadex G-100. Eluate samples were assayed for radioactivity, uronic acid and protein. Uptake rates of 67Ga in abscess increased with time after injection of turpentine and reached a plateau 5-7 days later. Ten minutes, 24 hours and 72 hours after injection of 67Ga, uptake rates of 67Ga in abscess were 0.92%/g, 3.3%/g and 5.6%/g, respectively. Uptake rates of 67Ga (24 hours after injection) in abscess was 2.0-3.4 time of tumor uptake rates (previously reported).(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1982

Mechanism of tumor and liver concentration of 111In and 169Yb: 111In and 169Yb binding substances in tumor tissues and liver.

Tumor-bearing animals were injected with 111In- and 169Yb-citrate. Tumor homogenates, from which the nuclear fraction was removed, and the mitochondrial fractions of the host livers were digested with pronase P. After digestion, the supernatants of the reaction mixtures were applied to Sephadex G-100 columns. The resultant eluates were analyzed for radioactivity, protein, uronic acid, and sialic acids. Three peaks of radioactivity were obtained by gel filtration. The first peak, eluted in the void volume, contained a species whose molecular weight exceeded 40 000. The second peak consisted of substances with molecular weights of 9400-40 000. Radioactivity in the third peak was liberated 111In and 169Yb. These two nuclides in the second peak were bound to acid mucopolysaccharides and/or the sulfated carbohydrate chain of sulfated glycoprotein. It was thought that the nuclides in the first peak might be bound to some acid mucopolysaccharides. The second peak nuclides seemed to be bound to acid mucopolysaccharide that contained no uronic acids, and/or to the sulfated carbohydrate chain of sulfated glycoprotein. It was concluded that they were bound to the acid mucopolysaccharides and/or the sulfated carbohydrate chain of sulfated glycoprotein in tumor tissues and liver lysosomes.

Animals↗
PubMed1981

Self-MHC-restricted cytotoxic T-cell response without thymic influence.

The thymus has a central role in directing the maturation and differentiation of T cells. These processes involve movement of cells. These processes involve movement of cells of haematopoietic origin through the thymus and are supposed to require intimate physical contact between T lymphocytes and cells of the thymic epithelium. Cytotoxic T cells (CTLs) induced by virus-infected or hapten-modified autologous cells exhibit dual specificity: for the products of the self major histocompatibility complex (MHC, H--2 in the mouse) and for the foreign antigen. It has been proposed that 'self' specificity of MHC-restricted CTLs is determined by the MHC-encoded antigens expressed on the surface of thymic epithelial cells. We show here that the differentiation of MHC-restricted CTLs can take place without thymic influence. In these experiments, self-MHC-restricted CTLs differentiate form spleen cells of nu/nu mice which lack thymuses after stimulation with 2,4,6-trinitrophenyl (TNP)-coupled autologous cells in the presence of T-cell growth factor.

Animals↗
PubMed1981

Subcellular distribution of 111In and 169Yb in tumor and liver.

Subcellular distribution of 111In and 169Yb was quantitatively determined to evaluate the role of the lysosome in the accumulation of these nuclides in malignant tumor tissue and in the liver using three different tumor models and the host liver. In Yoshida sarcoma and Ehrlich tumor, most of the radioactivity of these nuclides was localized in the supernatant fraction, and only a small amount of radioactivity was localized in the mitochondrial fraction, which contains lysosomes. In the liver, most of the radioactivity was concentrated in the mitochondrial fraction. The radioactivity of this fraction increased with time after the administration of these nuclides and reached approximately 50% of the total radioactivity within 24 h. In the case of hepatoma AH109A, radioactivity of the mitochondrial fraction increased with time after administration, and about 30% of the total radioactivity was concentrated in this fraction after 24 h. It is concluded that the lysosome does not play a major role in the tumor concentration of these nuclides, although it may play an important role in their liver concentration. In the case of hepatoma AH109A, it is presumed that lysosome plays a considerably important role in the tumor concentration of these nuclides, hepatoma AH109A possessing some residual features of the liver.

Animals↗
PubMed1979

[Studies of intrarenal distribution by macroautoradiogram and tissue distribution of 99mTc-gluconate (author's transl)].

1) The experimental studies have demonstrated that 99mTc-gluconate reaches a high concentration in the kidneys within 1-2 hours after injection and its concentration in organs adjacent to the kidney is low. 2) The initial images of serial macroautoradiograms visualized the inner medulla as well as the cortex and outex medulla, whereas the delayed images revealed only the outer cortex and outer stripes in the outer medulla. These findings suggest that this renal agent consists of two components and the delayed component deposits in the convoluted and straight segments of proximal tuble. 3) This renal agent visualizes the calyceal system and excretory pathways in the initial study and the renal morphology in the delayed study. Therefore, using this renal agent, it may be possible to evaluate a variety of renal diseases, including obstructive uropathy, space-occupying lesions, congenital deformities, etc,.

Animals↗
PubMed1978

[Whole-body retention studies of 167Tm-citrate.--Estimation of radiation dose to human from 167Tm-citrate--(author's transl)].

For the purpose of calculating absorbed dose to humans from 167Tm-citrate, the whole-body retention studies using 5 rats were carried out. Up to 40 days following intravenous injection of 167Tm-citrate, the whole-body counts were monitored with a animal counter. The whole-body retention curve was obtained with three exponentaial components. Namely, the 26% of the injected 167 Tm-citrate had a biological half-time of 3.4 hours, 12.5% had a biological half-time of 99 hours and 61.5% had a biological half-time of 106 days. These results indicate, that three components consist of the rapid clearance from the kidneys, the retention in the liver and other soft tissues with relatively long half-time and the retention in the bones with long half-time. Based on these biological data and the MIRD Committee method, the average dose estimates to the bone and whole-body from intravenous administration of 1 mCi 167Tm-citrate were 7.08 rads and 1.28 rads, respectively.

Animals↗
PubMed1977

Genetic control of primary and secondary IgG responses to sheep erythrocytes in mice.

The genetic control of the primary and secondary IgG responses to sheep erythrocytes has been studied by using inbred, H-2-congenic, and intra-H-2-recombinant mouse strains. According to our results, the primary IgG respone is under multigenic control. There is a correlation, however, between the titer of primary IgG antibodies produced and the H-2 phenotypes among the mouse strains tested. One H-2-linked gene maps at the I-B subregion, whereas another gene can be mapped at or closely linked to the H-2D region. Low and high responsiveness were associated with H-2b, H-2f and H2a, H-2d, H-2k phenotypes, respectively. By comparison of the responses of inbred and congenic strains having the same H-2 phenotype, it can be concluded that background genes influence the primary response only slightly but have almost complete control over the secondary response.

Animals↗
PubMed1977

[Relation between location of elements in periodic table and affinity for the malignant tumor (author's transl)].

Affinity of many inorganic compounds for the malignant tumor was examined, using the rats which were subcutaneously transplanted with Yoshida sarcoma. And the relations between the uptake rate into the malignant tumor and in vitro binding power to the protein were investigated in these compounds. In these experiments, the bipositive ions and anions had not affinity for the tumor tissue with a few exceptions. On the other hand, Hg, Au and Bi, which have strong binding power to the protein, showed high uptake rate into the malignant tumor. As Hg++, Au+ and Bi+++ are soft acids according to classification of Lewis acids, it was thought that these elements would bind strongly to soft base (R-SH, R-S-) present in the tumor tissue. In many hard acids (according to classification of Lewis acids), the uptake rate into the tumor was shown as a function of ionic potentials (valency/ionic radii) of the metal ions. It is presumed that the chemical bond of these hard acids in the tumor tissue is ionic bond to hard base (R-COO-, R-PO3(2-), R-SO3-, R-NH2).

Animals↗
PubMed1977

[Relations between location of elements in periodic table and affinity for the kidneys (author's transl)].

The distribution of many inorganic compounds in rats was investigated in order to evaluate kidney affinity of inorganic compounds. In these experiments, 30%, 10-20% and 4-10% of administered dose was localized in the kidneys in 203Hg-acetate and 203 Bi-acetate, in H198AuCl4, 103PdCl2, 201TlCl, 210Pd(NO3)2 and H2(127M)TeO3, and in Na2(51)CrO4, 54MnCl2, (114m)InCl3 and 7BeCl2, respectively. Some bipositive ions and anions was hardly taken up into the kidneys. And in many hard acids according to classification of Lewis acids, the uptake rate into the kidneys was usually small. On the other hand, Hg, Au and Bi, which have strong binding power to the protein, showed high uptake rate in the kidneys. As Hg++, Au+ and Bi+++ was soft acids according to classification of Lewis acids, it was thought that these elements would bind strongly to soft base (RSH, RS-) present in the kidney.

Animals↗
PubMed1977

[Study of distribution of 169Yb, 69Ga and 111In in tumor tissues by macroautoradiography; comparison between viable and necrotic tumor tissues].

The localization of 169Yb, 67Ga and 111In in tumor tissues was determined macroautoradiographically. 169Yb-citrate and 111In-citrate were injected intravenously to the rats subcutaneously transplanted Yoshida sarcoma and were injected intraperitoneally to the mice subcutaneously transplanted Ehrlich tumor. These animals were sacrificed 3, 24 and 48 hours after injection. These tumor tissues were frozen in n-hexane (-70 degrees C) cooled with dry ice-acetone. After this, these frozen tumor tissues were cut into serial thin sections (10 micron) in the cryostat (-20 degrees C). One of the slice of these sections was then placed on X-ray film and this film was developed after exposure of several days. On the other hand, next slice of these sections were then stained using the hematoxylin and eosin. From the observations of these autoradiogram and H-E stained slice, the following results were obtained. Concentration of 169Yb, 67Ga and 111In was predominant in viable tumor tissue rather than in necrotic tumor tissue, regardless of time after the administration. 67Ga and 111In were distributed uniformly in viable tumor tissue, but deposition of 169Yb was observed more avidly in viabl tumor tissue neighboring to necrotic tumor.

Animals↗