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Biomedical subjects

Y Sumi

Publications and source records attributed to Y Sumi.

At least 145 records · Page 8Linked to original sources
PubMed1990

Induction of pituitary tumors in germ-free rats exposed to Aspergillus versicolor.

We clarified the role of mold exposure in pituitary tumor induction using 53 germ-free Wistar rats exposed before birth and continually exposed thereafter, to Aspergillus versicolor alone. Rats were autopsied at 540 to 730 days. Untreated germ-free controls were autopsied on day 730. Thirty-three of the 53 monoassociated rats had pituitary tumors (62.3%), while only three of the 41 control germ-free rats had tumors (7.3%). It seems likely that this high incidence of pituitary tumor in the experimental rats is due to metabolites derived from the mold.

Adenoma↗
PubMed1990

[Non-quantitative analysis of the renography using 99mTc-DTPA; clinical efficacy and limitation].

The purpose of this paper is to evaluate the efficacy and limitation of the non-quantitative analysis of renography using 99mTc-DTPA, and to determine the clinical indication of the quantitative analysis of the study. We evaluated the clinical records of the patients and the findings of dynamic imagings and renograms. The non-quantitative analysis of the examination seemed to be useful to the selected cases, and quantitative analysis appeared to be dispensable except for the cases to evaluate the grade of parenchymal damages and causes of asymptomatic hematuria.

Adolescent↗
PubMed1989

Purification of human alpha 2-plasmin inhibitor using monoclonal antibody column chromatography.

alpha 2-Plasmin inhibitor (alpha 2PI) was purified directly from human plasma by using a monoclonal antibody affinity column, which recognizes the reactive site of alpha 2PI. alpha 2PI was eluted from the column under mild conditions with 50% v/v ethyleneglycol containing 0.05% Tween 80 in phosphate-buffered saline, pH 7.4. The yield was around 50% and the specific activity of the purified protein was the same as that of the best product of preparation conventionally purified alpha 2PI.

Antibodies, Monoclonal↗
PubMed1989

Expression and characterization of pro alpha 2-plasmin inhibitor.

alpha s-Plasmin inhibitor (alpha 2PI), one of the serine protease inhibitors in plasma, was expressed in baby hamster kidney (BHK) cell line. The expression vector was constructed with its genomic DNA and cDNA, and was transfected into BHK cells by the calcium phosphate method. The recombinant alpha 2PI which was secreted from the cells was estimated by SDS-PAGE to have a molecular mass of 67 kDa, which is indistinguishable from that of normal plasma alpha 2PI. The leader peptide of 12 amino acids was retained at the amino terminus of the recombinant alpha 2PI. This finding suggests that alpha 2PI has pre-pro type processing and the propeptide of 12 amino acids is not removed in BHK cells. This pro-alpha 2PI shows essentially the same inhibitory activity on plasmin and the same affinity for plasmin(ogen) as those of normal alpha 2PI. However, the cross-linking ability to fibrin is reduced to less than one-third of that of normal alpha 2PI. The cross-linking site is the glutamine residue located at the second position from the amino terminus of normal alpha 2PI. The conformational change of this region caused by the addition of the propeptide may have affected the cross-linking capacity of the inhibitor.

Amino Acids↗
PubMed1989

Studies on the relationships of IgA to human liver. IgA deposition in non-alcoholic liver diseases.

An investigation was conducted to clarify the relationships of IgA to the human liver. Immunocytochemical studies were performed on biopsy specimens from patients with cirrhosis and chronic hepatitis without any apparent history of alcohol abuse. The results showed that 1) a large amount of IgA is associated with the sinusoidal surface of hepatocytes, endothelial cells and Kupffer cells, 2) this IgA contains J chain and can form a complex with secretory component, and 3) this mainly belongs to the IgA1 subclass, 4) IgA in vesicles within hepatocytes and Kupffer cells is always associated with acid phosphatase activity, and 5) IgA containing vesicles within ductular epithelial cells always lack such enzyme activity. We conclude that 1) the IgA bound to the surface of hepatocytes, sinus endothelial cells and Kupffer cells is polymeric IgA1 uncomplexed with SC, and 2) this IgA occasionally enters these cells, and may be degraded in the lysosomes. 3) Polymeric IgA combines with SC in the ductular epithelium and may be secreted into bile. These findings suggest that J chain-linked polymeric IgA bound to the surface of hepatocytes and Kupffer cells has a certain pathological significance in liver diseases and might be involved in the clearance of excess IgA from the circulation.

Cell Membrane↗
PubMed1989

Clot lysis induced by a monoclonal antibody against alpha 2-plasmin inhibitor.

A monoclonal antibody (MoAb) to alpha 2-plasmin inhibitor designated JTPI-1 inhibited antiplasmin activity by interfering with formation of alpha 2-plasmin inhibitor (alpha 2-PI)-plasmin complex. With this MoAb, we observed plasma clot lysis in vitro and evaluated the potential of JTPI-1 to serve as a new therapeutic agent for thrombolysis. After adding 125I-labeled fibrinogen to plasma, clots were made by adding thrombin and calcium and were then resuspended in normal plasma containing various concentrations of JTPI-1. The presence of JTPI-1 enhanced release of the soluble 125I-labeled fibrin degradation fragment from the clots in a dose-dependent manner. With tissue plasminogen activator (t-PA)-depleted plasma, we showed that induction of clot lysis by JTPI-1 was dependent on fibrin-bound endogenous t-PA. Regulation of fibrinolysis initiated on the fibrin surface by fibrin-bound t-PA and plasminogen is mediated by alpha 2-PI cross-linked to fibrin by activated factor XIII. JTPI-1 bound to this cross-linked alpha 2-PI neutralized its activity and induced partial digestion of fibrin by plasmin. This resulted in additional binding of Glu-plasminogen to fibrin during the incubation. When 1.2 mumol/L JTPI-1 and 5 U/mL exogenous t-PA were present in the suspending plasma, the rate of clot lysis was essentially the same as that induced by 60 U/mL exogenous t-PA alone. These results suggest that JTPI-1 may be useful in reducing the amount of t-PA administered for thrombolytic therapy.

Antibodies, Monoclonal↗
PubMed1989

[A case of mixed müllerian tumor, usefulness of 67Ga-citrate scintigraphy].

Mixed Müllerian Tumor (M.M.T.) is a rare malignant neoplasm usually arising from uterine body in postmenoposal woman, and imaging diagnosis for the tumor has not been established. A 45-year-old female with pathologically confirmed M.M.T. was evaluated by 67Ga-citrate scintigraphy and CT on the basis of imaging diagnosis. 67Ga-citrate scintigraphy detected correctly not only primary lesions but also metastatic and recurrent-foci. The findings of 67Ga-citrate scintigraphy were confirmed to be correspond to autopsy findings. Generally, detectability of 67Ga-citrate scintigraphy for genito-urinary tract neoplasm was not appreciated, but in our case 67Ga-citrate scintigraphy was useful for detection of the primary lesion, metastatic and recurrent foci. The cellular components and grade of cell-differentiation of this tumor seemed to be responsible for good detection of the tumor. Thus, 67Ga-citrate scintigraphy was considered to be useful diagnostic imaging modality of M.M.T.

Female↗
PubMed1989

[67Ga-scintigraphic finding of colorectal carcinoma; the basis of clinicopathologic viewpoint].

Twenty-seven cases of colorectal carcinoma were evaluated by 67Ga-scintigraphy on the basis of clinicopathologic viewpoint. On each cases, 67Ga-scintigraphy was performed just before the operation, and resected specimen was also examined after the operation. In 17 cases (63%), the lesions were demonstrated on preoperative 67Ga-scintigraphy, on the other hand, all the lesions were clearly detected on images taken from resected specimen. Thus, it seems to be no doubt to accumulate 67Ga-citrate to colorectal carcinoma, and 67Ga-scintigraphy appears to be more useful imaging modality to detect the disease when the routine detectability becomes more higher because of some technical application.

Adenocarcinoma↗
PubMed1989

[Preliminary study of patients with vertigo and dizziness using 123I-IMP].

To study the application of cerebral blood flow scintigraphy with 123I-IMP for the evaluation of central dizziness, the difference in 123I-IMP accumulation between the right and left cerebellar hemispheres was determined as an asymmetry index (A.I.) in 8 normal subjects and compared with A.I. from patients with central dizziness. According to estimated lesions, 123I-IMP findings were compared with CT findings. The normal subjects had A.I. of 5.8 +/- 2.1%, whereas 36 patients with central dizziness had A.I. of 12.7 +/- 7.5%. On the basis of an A.I. of 8% or more as an abnormal finding on IMP scintigraphy, 11 of the 14 patients with estimated lesions of cerebellar hemispheres and 16 of the 20 with those of the whole cerebellum including the vermis were evaluated to have had abnormalities. Seven of 11 with estimated lesions of the brainstem and 4 of 5 with vertebrobasilar arterial insufficiency were evaluated to have had abnormalities. The findings of 123I-IMP cerebral blood flow scintigraphy were in good agreement with clinical symptoms in patients with central dizziness with estimated lesions of the cerebellar hemispheres, suggesting the possibility that this method is more useful than CT.

Adult↗
PubMed1989

[Reliability of the lipid emulsion test for reticuloendothelial system].

The reticuloendothelial system is important as one of the self defense mechanisms. We performed two investigations to confirm the reliability of the lipid emulsion test for determining the reticuloendothelial system function. 1) The lipid emulsion serum clearance was contrasted with the counts of lipid emulsions phagocytosed by Kupffer cells in liver. 2) Lipid emulsion clearance was contrasted with the hepatic uptake rate of 99mTc-phytate. The result demonstrated a positive correlation among lipid emulsion clearance, the counts of lipid emulsions phagocytosed by Kupffer cells and the hepatic uptake rate of 99mTc-phytate. These results confirm that the lipid emulsion test is sufficient to reflect Reticuloendothelial system function.

Adult↗
PubMed1988

Organization of the human alpha 2-plasmin inhibitor gene.

We have isolated overlapping phage genomic clones covering an area of 26 kilobases that encodes the human alpha 2-plasmin inhibitor. The alpha 2-plasmin inhibitor gene contains 10 exons and 9 introns distributed over approximately 16 kilobases of DNA. To our knowledge, the number of introns is the highest yet reported for a member of the serine protease inhibitor (serpin) superfamily. All introns are located in the 5'-half of the corresponding mRNA. The 5'-untranslated region and the leader sequence are interrupted by 3 introns totaling approximately equal to 6 kilobases. A "TATA box" sequence is located 17 nucleotides upstream from the proposed transcription initiation site. Multiple "GC box" sequences, G + C-rich sequences, and "CCAAT box"-like sequence, the hepatitis B virus enhancer element-like sequence and the human immunodeficiency virus enhancer-like sequence appear in the 5'-flanking region. The NH2-terminal region, which implements factor XIII-catalyzed cross-linking of alpha 2-plasmin inhibitor to fibrin, is encoded by the 4th exon. The reactive site and plasminogen-binding site, both located in the COOH-terminal region, are encoded by the 10th exon. When similar amino acids of alpha 2-plasmin inhibitor and other members of the serpin gene superfamily are aligned, the position of the 7th intron of the alpha 2-plasmin inhibitor gene aligns precisely with that of the second intron of the genes for rat angiotensinogen and human alpha 1-antitrypsin genes and is misaligned by only one nucleotide with that of the third intron of antithrombin III, suggesting that the alpha 2-plasmin inhibitor gene originates from the common ancestor of these serine protease inhibitors.

Amino Acid Sequence↗