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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 1,333 records · Page 74Linked to original sources
PubMed1984

Radiological features of familial polyposis coli: grouping by polyp profusion.

The radiological features of familial polyposis coli (FPC) were studied in 60 patients by double-contrast barium enema examinations. When classified by profusion of polyps, cases fell into two groups: the profuse type and the sparse type. The radiologically determined boundary range distinguishing these types was 6-9 polyps/cm2 in adult patients and 3-6 in children. But on grouping the FPC patients by size of the polyps, one group of 34 cases had one or more polyps of more than 1 cm diameter, and in 16 of this group, one or more advanced cancers were histologically demonstrated; whereas in the group of 20 patients, in which the lesions were 5 mm or less, no malignancy was detected. In contrast to cases of the sparse type, in which the size of the polyps bore no relation to age, all cases of the profuse type who were 15 years old or more had polyps more than 1 cm in diameter.

Adolescent↗
PubMed1984

Synthesis of [N-methyl-3H]-7-chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2 H-1,4-benzodiazepin-2- one (3H-fludiazepam) by phase transfer catalysis.

[N-methyl-3H]-7-Chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2H-1,4- benzodiazepin-2- one ( [3H]fludiazepam) was prepared by phase transfer catalytic N-methylation of the corresponding nor-derivative with [3H]methyl iodide [407 GBq/mmol (11 Ci/mmol)] in a radiochemical yield of 34%. The specific activity was 271.6 GBq/mmol (7.34 Ci/mmol).

Anti-Anxiety Agents↗
PubMed1984

[Successful resection of giant hepatocellular carcinoma with hypoglycemic attack].

We experienced a 68 years-old male who had frequent hypoglycemic attacks. The diagnosis of a giant hepatoma associated with hypoglycemia was established by oral glucose tolerance test (O-GTT), angiography and computed tomography. The cavography demonstrated the invasion or depression of the tumor. It was ascertained by an operative exploration that the tumor occupied most of the right trisegments of the liver and infiltrated into a part of the left lateral segment. The right hepatic trisegmentectomy along 1.5cm left side line apart from the falciform ligament was performed. Resected tumor showed 11 X 13 X 10cm in size and 1200g in weight. Microscopic findings demonstrated hepatocellular carcinoma as Edmondson's Type II. After the operation, this patient became free from the hypoglycemic attack. A fasting blood sugar became within normal limits and O-GTT demonstrated a normal blood sugar level and insulin response. No concentration of immuno-reactive insulin was found in the resected tumor, however, the blood sugar in rats which received the intravenous injection of the tumor extracts was remarkably decreased in 20 minutes. From these observation, hypoglycemia in this patient seemed to depend mainly on the factor of insulin-like activity of the tumor. In the literature, the hepatocellular carcinoma associated with paraneoplastic phenomenon, e.g. hypoglycemia, has rarely been resected because of accompanied liver cirrhosis or giant size of the tumor. This is the second patient in our country in whom the tumor was fortunately resected and the paraneoplastic syndrome disappeared postoperatively.

Aged↗
PubMed1984

Abnormal expression of interleukin-2 receptor (Tac antigen) in adult T-cell leukemia.

Human T-cell leukemia/lymphoma virus type I(HTLV-I) infection appears to be closely associated with the leukemogenesis of adult T-cell leukemia (ATL), although its mechanism remains unclear. Since our previous report that leukemic cells from patients with ATL expressed Tac antigen (Ag) (interleukin-2 (IL-2) receptor) on their cell surface, we have been studying IL-2 receptors on ATL leukemic cells to see whether they are different from normal IL-2 receptors and whether they play a role in the neoplastic growth of ATL cells. Peripheral blood leukemic cells from 35 patients with ATL expressed IL-2 receptors which were detected by anti-Tac monoclonal antibody when examined immediately after the separation of cells or after culture for 24 or 48 hr. The number of anti-Tac binding sites ranged from 4,300 to 11,400 in fresh cells and from 6,100 to 96,000/cell in short term cultured leukemic cells, whereas phytohemagglutinin-P(PHA-P)-stimulated normal T cells exhibited 7,000 to 35,000 anti-Tac binding sites/cell. HTLV-I-infected cell lines such as MT-1 and HUT-102 expressed a markedly enhanced number of Tac Ag molecules. Leukemic cells from 15 ATL patients showed no or very poor proliferative response to various concentrations of IL-2, although they expressed Tac Ag. Radiolabeled IL-2 binding experiments revealed that ATL leukemic cells could bind IL-2 although the number of IL-2 binding sites was much less than that of anti-Tac binding sites. IL-2 receptors on ATL cells, unlike normal activated T cells, were not modulated (down-regulated) by anti-Tac antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Surface↗
PubMed1984

Destruction of rabbit knee hyaline cartilage associated with surface antigen-antibody interaction during the Arthus reaction of antigen-induced arthritis.

Ultrastructural changes occurring in rabbit hyaline cartilage were studied during the early stages of antigen-induced arthritis. After one hour, small deposits of electron-dense material (EDM) were noted at depths up to about 3 micron from the surface. During subsequent stages, the number of EDM deposits did not increase, but by 12 hours they had grown to large aggregates. At the surface, extensive deposition and growth eventually resulted in exfoliation of surface layers of cartilage, exposing a fissured matrix. From previous evidence, EDM has been equated with immune complexes (antigen and homologous antibody). The mechanism of cartilage destruction is therefore closely linked to reactions of antigen and antibody within the hyaline cartilage. Mechanical and/or biochemic processes may be involved, but cells do not appear to participate in the destructive process, at least not in regions remote from pannus.

Animals↗
PubMed1984

Characterization of human interleukin 2 receptor (Tac antigen) in normal and leukemic T cells: co-expression of normal and aberrant receptors on Hut-102 cells.

Human interleukin 2 receptors ( IL2R ) from various cell sources such as mitogen-activated normal human T cells, adult T cell leukemia (ATL)-derived cell line cells (MT-1, ATL-6, Hut-102), and a natural killer-like cell line YT cells, were studied both by one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), with a monoclonal anti- IL2R antibody (anti-Tac). In synthetic labeling with [35S]methionine, anti-Tac specifically precipitated two glycoproteins, one with m.w. of 60,000 to 65,000 and pI 4.2 to 4.7, and the other with m.w. about 40,000 and pI 6.2 to 6.5. A study of surface iodination revealed that the former component was membrane-associated mature IL2R , and a pulse-chase study showed that the latter component was a precursor for IL2R that already possessed tunicamycin-sensitive N-linked sugar side chain(s). This precursor was found to be posttranslationally processed into mature IL2R by further glycosylation within 240 min. Among the cells studied, a human T cell leukemia virus-positive leukemic cell line, Hut-102, was distinctive in that it possessed an additional membrane glycoprotein (m.w. 55,000 to 60,000, pI 4.2 to 5.0) also defined by anti-Tac. This unique glycoprotein of Hut-102 cells appeared to be an aberrant IL2R .

Adult↗
PubMed1984

[Distribution of fibronectin and other plasma proteins in gastric cancer tissues: investigation of mechanisms of desmoplasia of the stroma].

To elucidate the mechanisms of desmoplasia of gastric cancer tissues, distribution of fibronectin (FN), fibrinogen (Fbg), alpha 2-plasmin inhibitor (alpha 2PI) and factor XIII (XIIIA) in fresh 49 gastric cancer tissues and 5 gastric ulcer tissues was studied by indirect immunofluorescent technique. FN existed scarcely in the basement membrane area of gastric cancer tubuli. FN and Fbg were distributed in same patterns abundantly in the stroma of all gastric cancer tissues regardless of their histological types. Neither alpha 2PI nor XIIIA was demonstrated in gastric cancer tissues. Autofluorescence of the cross-linked collagen fibers, which were seen in many gastric cancer cases, were surrounded with FN and Fbg. These results were well identical with those obtained from gastric ulcer tissues. These facts indicate that such a mechanism as non-specific wound healing process participates in desmoplasia of gastric cancer stroma as well as in fibrosis of gastric ulcer.

Blood Proteins↗
PubMed1984

Properties of human interleukin-2 receptors expressed on non-lymphoid cells by cDNA transfection.

We have established non-lymphoid cell lines HeLa, Ltk and NIH3T3 expressing the human interleukin-2 (IL-2) receptor by transfection of human IL-2 receptor complementary DNA. While IL-2 receptors on T cells are classified into the high and low affinity species, the receptors expressed on the cDNA-transfected non-lymphoid cells belong to the low affinity species. These IL-2 receptors could not transmit the growth signal although they were similar in size to those expressed on T cells. Phorbol ester-induced phosphorylation of the IL-2 receptors on HeLa cells did not affect the affinity of the receptor. We have also constructed a cDNA encoding a mutant IL-2 receptor that replaced the major phosphorylation site, the serine residue at position 247 with the glycine residue. This mutant IL-2 receptor expressed on non-lymphoid cells also had the low affinity for IL-2. The results indicate that the high and low affinity states of the IL-2 receptor are not solely determined by phosphorylation of the receptor. The IL-2 receptors expressed on these non-lymphoid cells were internalized four to eight times more slowly than those on T cells. Possible defects of the IL-2 receptors expressed on non-lymphoid cells are discussed.

Animals↗