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Biomedical subjects

J Abe

Publications and source records attributed to J Abe.

At least 91 records · Page 5Linked to original sources
PubMed1995

Spontaneous generation of human CD8+ TCR alpha beta+ cells derived from precursors within the double negative compartment.

Flow cytometric analysis demonstrated that fresh human thymocytes contain only a low level of mature CD8+ TCR alpha beta + or CD8+ TCR gamma delta + cells and they consist consist of approximately 70% double positive (DP) and approximately 10% double negative (DN) cells. These unfractionated thymocytes could be selectively expanded in vitro by stimulation with 12-O-tetradecanoylphorbol 13-acetate (TPA) and PHA in the presence of IL-2. The majority of the cells expanded from unfractionated thymocytes expressed CD3, TCR alpha beta and CD8 molecules after long-term culture (18 days). When highly purified DN thymocytes were expanded over a period of 18 days in the presence of DP cells, they also co-expressed CD3, TCR alpha beta and CD8 molecules on their surface. However, when purified DN thymocytes were expanded alone, that is, in the absence of DP cells for 18 days, they expressed CD3-associated TCR gamma delta, but not CD8 or TCR alpha beta. Despite the expression of measurable levels of IL-2 alpha and beta receptors, as well as a significant level of TCR alpha beta, purified DP cells failed to proliferate. These findings provide the first evidence, in humans, that the progression of precursor cells in the DN compartment to a later stage of differentiation can be induced outside the thymus and that DP cells can affect the development of TCR expression in proliferating DN thymocytes.

CD8-Positive T-Lymphocytes↗
PubMed1995

Analysis of seven pedigrees of childhood Wilson's disease characterized by abdominal symptoms.

In a survey of childhood Wilson's disease (WD) characterized by abdominal symptoms, three patients with high levels of immunologically detectable ceruloplasmin (CP) in serum were found. These three cases were compared with typical cases of WD in which serum CP level was low. In order to clarify the cause of WD, serum CP levels were quantified by two methods, an immunological protein assay and an oxidase activity assay. Using the results of these two assays, WD cases were classified into three groups on the basis of CP content; the first group consisted of patients with low enzyme activity and low CP protein content, the second group consisted of patients with low enzyme activity and normal CP protein content, and the third group, those patients with normal enzyme activity and normal CP protein content. No significant difference in symptoms was observed between these three groups. Since relatively high levels of CP were detected in some WD patients, genetic variation in CP in WD patients was examined by restriction enzyme fragment length polymorphism analysis using CP cDNA. However, no large deletion in the CP gene was detected. Using four types of gene probes for chromosome 13 known to be related to WD, the DNA of WD patients was examined in a similar fashion, but no significant difference was observed between the groups.

Abdomen↗
PubMed1995

Accelerated ventricular rhythm in the newborn.

Accelerated ventricular rhythm was observed in two newborn infants. Neither of them had any causative clinical symptoms for the ventricular arrhythmia. The arrhythmia disappeared when the infants were 18 days and 45 days old, respectively. Arrhythmia was noted in the fetal period, especially in case 1.

Age Factors↗
PubMed1995

Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions.

The clinicopathological features of a previously unrecognised type of acute encephalopathy prevalent among Japanese children is described by reviewing the records of 13 consecutive patients treated and 28 previously reported cases. The hallmark of this encephalopathy, proposed to be a novel entity termed acute necrotising encephalopathy of childhood, is multiple, necrotic brain lesions showing a symmetric distribution. The encephalopathy was noted in previously healthy children after respiratory tract infections, with presenting symptoms of coma, convulsions, vomiting, hyperpyrexia, and hepatomegaly. Laboratory examinations disclosed liver dysfunction, uraemia, and hypoproteinaemia. The histological appearance of the liver was variable and non-specific. Cerebrospinal fluid contained an increased amount of protein. Computed tomography and MRI showed the presence of symmetrically distributed brain lesions of the thalamus, cerebral white matter, brainstem, and cerebellum. Necropsy examination confirmed extensive fresh necrosis of these regions with evidence of local breakdown of the blood-brain barrier. Based on the characteristic combination of clinical and pathological findings, acute necrotising encephalopathy of childhood can be distinguished from previously known encephalopathies, including Reye's syndrome.

Acute Disease↗
PubMed1995

1,25-Dihydroxyvitamin D3 upregulates the phosphatidylinositol signaling pathway in human keratinocytes by increasing phospholipase C levels.

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) induces the differentiation of normal human keratinocytes, in part by increasing their basal intracellular calcium levels (Cai) over a period of hours. Agonists such as ATP acting through membrane receptors cause an immediate but transient increase in Cai accompanied by an increase in inositol trisphosphate (IP3). Treatment of keratinocytes for 24 h with 1 nM 1,25(OH)2D3 resulted in a two- to four-fold potentiation of the Cai response of these cells to ATP. This potentiation was inhibitable with cycloheximide, unaccompanied by a change in total intracellular calcium pools, but associated with an increase in basal IP3 levels and ATP-stimulated IP3 production. Treatment with 1,25(OH)2D3 raised the protein and mRNA levels of phospholipase C isoenzymes, particularly phospholipase C-beta 1 in a dose-dependent manner. These studies indicate that 1,25(OH)2D3 modulates the keratinocyte signal transduction pathway by induction of phospholipase isoenzymes, a previously undescribed action for this hormone.

Adenosine Triphosphate↗
PubMed1994

Purification and characterization of a novel superantigen produced by a clinical isolate of Yersinia pseudotuberculosis.

A superantigen designated as Yersinia pseudotuberculosis-derived mitogen (YPM) was purified in an equal manner from both the culture supernatant and cell lysate of a clinical isolate (KUR-1) of Y. pseudotuberculosis serotype 4b. A significant proliferative response of human peripheral blood mononuclear cells to purified YPM was detectable even at a concentration of 1 pg/ml. The N-terminal sequence of YPM which included 23 amino acid residues was determined, by automated Edman degradation, as Thr-Asp-Tyr-Asp-Asn-Thr-Leu-Asn-Ser-Ile-Pro-Ser-Leu-Arg-Ile-Pro-Asn-Il e-Ala-Thr-Tyr-Thr-Gly-. This sequence differed from not only all the, hitherto, reported superantigens but also known proteins. While molecular weights of known bacterial superantigens are more than 22,000, electrospray ionization mass spectrometry showed that the molecular weight of YPM was 14524.4. These results indicate that YPM comprises a novel superantigen with substantial structural differences from other bacterial superantigens produced by Gram-positive cocci.

Amino Acid Sequence↗
PubMed1994

Adoptive immunotherapy with murine tumor-specific T lymphocytes engineered to secrete interleukin 2.

Adoptive immunogene therapy of cancer is not widely studied, although it has been proposed as a promising strategy for cancer gene therapy. One of the major obstacles to this approach is the difficulty in introducing cytokine genes efficiently into T lymphocytes. In this report, we developed an adoptive immunotherapy model with murine tumor-specific cytotoxic T lymphocytes. By using an adenoviral vector, we achieved up to 100% gene transduction of murine T lymphocytes. Treatment of mice with the cytotoxic T lymphocytes genetically modified to produce interleukin 2 resulted in reduction of tumor metastasis and longer survival from intracerebral tumor death, providing a hopeful strategy for treatments of human cancers.

Adenoviridae↗
PubMed1994

A fumagillin derivative angiogenesis inhibitor, AGM-1470, inhibits activation of cyclin-dependent kinases and phosphorylation of retinoblastoma gene product but not protein tyrosyl phosphorylation or protooncogene expression in vascular endothelial cells.

Fumagillin analogue AGM-1470 potently inhibits angiogenesis with a minimal toxicity in vivo and is expected to be of therapeutic use as a powerful antitumor agent (Ingber et al., Nature, 348:555-557, 1990). In the present study, we have investigated the effects and the mechanism of action of AGM-1470 on cultured human umbilical vein endothelial cells. AGM-1470 acts directly on endothelial cells to inhibit growth factor-induced DNA synthesis, with half maximal and maximal effects obtained at approximately 2 x 10(-10) and 5 x 10(-9) M, respectively. AGM-1470 does not inhibit early G1 mitogenic events, such as cellular protein tyrosyl phosphorylation or the expression of immediate early genes c-fos and c-myc, but potently inhibits phosphorylation of RB protein, a tumor suppressor retinoblastoma gene product. The later addition of AGM-1470 up to 3 h after the growth factor stimulation still exerts full inhibitory effects on both DNA synthesis and RB phosphorylation, suggesting that the major site of action of AGM-1470 is located relatively late in the G1 phase. AGM-1470 inhibits growth factor-induced activation of candidate RB kinases cdc2 and cdk2 but fails to inhibit them directly in vitro. AGM-1470 completely abolishes the growth factor-induced mRNA expression of cdc2 and cyclin A and partially inhibits that of cyclin E but has little effect on the mRNA level of cdk2, cdk4, or cyclin D1. These results indicate that angioinhibitory action of AGM-1470 involves suppression of mRNA expression of specific members of cdks and cyclins and of activation of both cdc2 and cdk2 kinases in endothelial cells.

CDC2 Protein Kinase↗
PubMed1994

Crystal and molecular structure of barley alpha-amylase.

The three-dimensional structure of barley malt alpha-amylase (isoform AMY2-2) was determined by multiple isomorphous replacement using three heavy-atom derivatives and solvent flattening. The model was refined using a combination of simulated annealing and conventional restrained least-squares crystallographic refinement to an R-factor of 0.153 based on 18,303 independent reflections with F(o) > sigma(F(o)) between 10 and 2.8 A resolution, with root-mean-square deviations of 0.016 A and 3.3 degrees from ideal bond lengths and bond angles, respectively. The final model consists of 403 amino acid residues, three calcium ions and 153 water molecules. The polypeptide chain folds into three domains: a central domain forming a (beta alpha)8-barrel of 286 residues, with a protruding irregular structured loop domain of 64 residues (domain B) connecting strand beta 3 and helix alpha 3 of the barrel, and a C-terminal domain of 53 residues forming a five stranded anti-parallel beta-sheet. Unlike the previously known alpha-amylase structures, AMY2-2 contains three Ca2+ binding sites co-ordinated by seven or eight oxygen atoms from carboxylate groups, main-chain carbonyl atoms and water molecules, all calcium ions being bound to domain B and therefore essential for the structural integrity of that domain. Two of the Ca2+ sites are located only 7.0 A apart with one Asp residue serving as ligand for both. One Ca2+ site located at about 20 A from the other two was found to be exchangeable with Eu3+. By homology with other alpha-amylases, some important active site residues are identified as Asp179, Glu204 and Asp289, and are situated at the C-terminal end of the central beta-barrel. A starch granule binding site, previously identified as Trp276 and Trp277, is situated on alpha-helix 6 in the central (beta alpha)8-barrel, at the surface of the enzyme. This binding site region is associated with a considerable disruption of the (beta alpha)8-barrel 8-fold symmetry.

Amino Acid Sequence↗
PubMed1994

Characterization, crystallization and preliminary X-ray crystallographic analysis of the complex between barley alpha-amylase and the bifunctional alpha-amylase/subtilisin inhibitor from barley seeds.

The complex between a member of the barley malt alpha-amylase isozyme 2 family (AMY2-2), and the endogenous bifunctional alpha-amylase/subtilisin inhibitor, BASI, has been crystallized by the hanging drop vapour diffusion technique at a AMY2-2: BASI molar ratio of 1:1. Crystals have been grown within 4 days from solutions containing polyethylene glycol and calcium chloride. Analysis of single crystals by gel electrophoresis showed the presence of both proteins in the crystal lattice. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 74.5 A, b = 96.9 A, c = 171.3 A and they diffract to 2.0 A resolution. The presence of two molecules of the 1:1 complex in the asymmetric unit gives a solvent content of 45% by volume. The 1:1 stoichiometry of the complex was confirmed by the molecular replacement method, using as a search model the recently determined three-dimensional structure of the barley alpha-amylase.

Crystallization↗
PubMed1994

Suppression of neointimal smooth muscle cell accumulation in vivo by antisense cdc2 and cdk2 oligonucleotides in rat carotid artery.

Deendothelializing balloon injury of rat carotid artery results in progressive intimal smooth muscle cell accumulation and luminal stenosis over 14 days after injury. We have found transient rises (approximately 3-fold maximal increases over the uninjured control value) of the kinase activities of both cdc2 and cdk2, key molecules for cell cycle progression, in the injured carotid artery along with the development of intimal proliferation. The topical application of the antisense, but not the sense, cdc2 and cdk2 phosphorothioate oligodeoxynucleotides dissolved in F127 pluronic gel around the freshly injured artery resulted in reductions of the intimal smooth muscle cell accumulation by 47% and 55% respectively, as estimated by an intimal to medial cross-sectional area ratio, with concomitant decreases in cdc2 and cdk2 kinase activities. These results indicate that both cdc2 and cdk2 kinases are involved in intimal smooth muscle cell accumulation after balloon angioplasty and suggest a potential usefulness of the antisense cdc2 and cdk2 oligonucleotide therapy for arterial stenosis.

Angioplasty, Balloon↗
PubMed1994

Angiographic follow-up after successful percutaneous coronary angioplasty for chronic total coronary occlusion: experience in 110 consecutive patients.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 110 consecutive patients (111 vessels) with chronically occluded coronary arteries and was successful in 69 patients (69 vessels). Successful initial PTCA was related to the extent of coronary artery disease, the morphology of the proximal surface of the occlusion site, and the clinical duration of occlusion. Repeat angiography was performed for 62 patients, with successful initial PTCA and demonstrated restenosis in 34 (55%) patients, of whom 11 had total occlusion. Repeat PTCA was performed in 30 patients and was successful in 80%. Follow-up angiography after repeat PTCA was carried out in all patients who underwent successful second PTCA, and, it demonstrated re-restenosis in 7 (29%) patients. In this study, among 111 total occlusions, 28 vessels undergoing successful initial PTCA and 17 undergoing successful repeat PTCA were free from restenosis or re-restenosis at the time of follow-up angiography.

Adult↗
PubMed1994

Classical pathway complement activation in Kawasaki syndrome.

In this study the complement breakdown products C3d, C4d, Bb and membrane attack complex were measured in plasma of patients with Kawasaki syndrome. The results suggested strong activation of the classical activation pathway. However, there was no significant decrease in hemolytic titer or in the concentrations of the intact proteins C3, C4, and B. The relationship between the serum concentrations of cytokines and complement components was examined; increased interleukin-6 concentration on the fifth day after the onset of fever was found to correlate well with the C3 and B concentrations in serum obtained 5 days later. We conclude that complement activation occurred in Kawasaki syndrome via the classical pathway but that the inflammatory reaction was accompanied by increased production of complement components. As a result, there was increased formation of activation products without changes in the serum complement levels.

Child, Preschool↗
PubMed1994

Purification and characterization of periplasmic alpha-amylase from Xanthomonas campestris K-11151.

Xanthomonas campestris K-11151, isolated from soil, produced a periplasmic alpha-amylase of a new type. The enzyme was purified to homogeneity, as shown by several criteria. The purified enzyme showed almost the same activities on alpha-, beta-, and gamma-cyclodextrins, soluble starch, and amylose. Moreover, it was active on branched cyclodextrins, pullulan, and maltose but not on glycogen. Kinetic analysis showed that alpha-cyclodextrin was the best substrate among the cyclodextrins. The substrate specificity suggested that this enzyme had the combined activities of alpha-amylase, cyclodextrinase, and neopullulanase.

Amylopectin↗
PubMed1994

Topical application of AT1 receptor antagonists prevents medial and neointimal proliferation after balloon injury.

Angiotensin II plays an important role in neointima formation after vascular injury. A rat model of carotid artery injury was used i) to investigate the effect of single topical application of angiotensin II subtype 1 (AT1) receptor antagonists (CV11974, DuP753) in suppressing medial proliferation at day 2 and neointimal proliferation at day 14, and ii) to investigate the antiproliferative effects of additional application of L-arginine (a nitric oxide precursor). Drugs mixed in 25% (W/W) solutions of F127 pluronic gel were applied topically to injured vessels. Early medial proliferation of smooth muscle cells, assessed by the S-bromo-2'-deoxyuridine labelling index, was significantly suppressed by application of CV11974 (5 mg/kg), 7.5% +/- 2.2% vs. 19% +/- 3.9% in the control group. The intima/media ratio following CV11974 (10 mg/kg) or DuP753 (12.5 mg/kg) at day 14 was significantly lower than that in the control group (42% +/- 7%, 43% +/- 14%, and 123% +/- 11%, respectively). Additional application of L-arginine seemed to increase effectiveness, but was not statistically significant. In conclusion, single topical application of AT1 receptor antagonists was effective in suppressing early medial proliferation and neointima formation after balloon injury, suggesting that they may be clinically useful after angioplasty or vascular surgery.

Administration, Oral↗