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M Isobe

Publications and source records attributed to M Isobe.

At least 235 records · Page 13Linked to original sources
PubMed1994

Comparative DNA analysis by image cytometry and flow cytometry in non-small cell lung cancer.

To determine whether image cytometry (ICM) is advantageous for clinical DNA analyses of tumor cells, nuclear DNA contents measured by ICM were compared with those by flow cytometry (FCM), using 46 samples of non-small cell lung cancers. ICM was performed on smear specimens of fresh materials (f-ICM) and cell suspensions obtained from paraffin-embedded tumors (p-ICM). The same cell suspensions were also analyzed by FCM (p-FCM). Aneuploid rates/coefficient of variation (CV) of f-ICM, p-ICM, and p-FCM were 76.1/4.90, 71.7/5.01 and 60.9/5.31%, respectively. There was a high correlation in the DNA indices between p-ICM and p-FCM (r = 0.80). In the comparative DNA analysis, there were seven discordant samples. Six of them were estimated as aneuploid by p-ICM, but they were miscounted as diploid or undefinable (impossible) by p-FCM. This was caused by measuring condensed nuclei or debris. All "impossible" samples in p-FCM were squamous cell carcinoma with necrosis. In cell cycle analysis, the S and S+G2/M phase fractions in diploid samples were higher in p-ICM than those in p-FCM (P < 0.005), because the G0/G1 phase (2N) fraction presented by FCM was composed of cancer and non-malignant cells in diploid cancers. In ICM, they can be separately measured by means of morphological selection. These findings indicated that ICM is superior to FCM, especially for the practical DNA measurement of a few cancer cells and in the evaluation of the proliferation rates.

Adult↗
PubMed1994

Chromosomal localization of an SH2 containing tyrosine phosphatase (SH-PTP3) gene to chromosome 12q24.1.

A genomic DNA fragment, isolated from a human phage library using a human BPTP3 cDNA probe, was shown to be derived from the human SH-PTP3 (also called SH-PTP2, PTP-1D, PTP-2C, or Syp) locus. We have used fluorescent in situ hybridization (FISH) to map SH-PTP3 in chromosome band 12q24.1, a region vicinity to the second locus for autosomal dominant cerebellar ataxia (SCA2).

Amino Acid Sequence↗
PubMed1993

Chromosome walking on the TCL1 locus involved in T-cell neoplasia.

The TCL1 locus on chromosome 14 band q32.1 is frequently involved in the chromosomal translocations and inversions with the T-cell receptor genes observed in several T-cell tumors, including T-prolymphocytic leukemias, acute and chronic leukemias associated with the immunodeficiency syndrome ataxia-telangiectasia, and adult T-cell leukemia. All breakpoints cloned in this area have been mapped to 14q32.1, an area distant approximately 10,000 kb from the immunoglobulin heavy-chain gene locus on chromosome 14q band 32.3. Except for two cases of inversion, no physical linkage of the cloned breakpoints has been reported, nor has a gene been identified in this region. Taking advantage of chromosome-walking techniques and of the P1 phage, we cloned and characterized 450 kb of the germ-line TCL1 locus, starting from the breakpoints of two independent T-cell leukemias. We show that all molecular rearrangements characterized so far map to these clones, indicating not only that this region is the target of chromosomal rearrangements occurring in this area but also that both inversion and translocations occur within a 300-kb region in the T-cell leukemias. In the attempt to identify a candidate oncogene responsible for the malignant transformation, a CpG island centromeric to the inversions and to the translocations has been identified. Two probes near the CpG island have detected sequences conserved among species, as well as two transcripts in the K562 human erythroleukemia cell line. On the basis of these data, a model of activation of the putative TCL1 oncogene is suggested.

Base Sequence↗
PubMed1993

Precursor polyprotein for multiple neuropeptides secreted from the suboesophageal ganglion of the silkworm Bombyx mori: characterization of the cDNA encoding the diapause hormone precursor and identification of additional peptides.

Peptidergic neurons, which serve as source of various endocrine neuropeptides, were identified in the suboesophageal ganglion (SG) and brain of insects. In the silkworm Bombyx mori, SG is known to secrete two neuropeptides, diapause hormone (DH) responsible for induction of embryonic diapause and pheromone biosynthesis-activating neuropeptide, which share a pentapeptide amide, Phe-Xaa-Pro-Arg-Leu-NH2 (Xaa = Gly or Ser), at the C terminus. We have isolated cDNA clones for DH from the cDNA library of SG by using oligonucleotide probes. The molecular characterization of the cDNA reveals that the mRNA encodes an open reading frame consisting of 192 aa residues in which the 24-aa DH peptide is localized at the N-terminal region just after the signal peptide. A homology search proposed that the cDNA encodes pheromone biosynthesis-activating neuropeptide and three other neuropeptides [alpha-, beta-, and gamma-SG neuropeptide (SGNP)] in the region following DH, all of which are flanked by possible tryptic cleavage sites and share the Phe-Xaa-Pro-Arg-Leu-Gly sequence at the C terminus. Northern hybridization analysis clearly showed that the gene expression was limited to SG. We chemically synthesized alpha-, beta-, and gamma-SGNP and used them to identify components in extracts of SG and to examine biological functions, alpha- and gamma-SGNP were identified in extracts of SG, and the synthetic beta- and gamma-SGNP expressed weak DH activity. These results indicate that DH, along with four other neuropeptides, is generated from a common precursor polyprotein that is encoded by a single mRNA transcribed in neurosecretory cells of SG.

Amino Acid Sequence↗
PubMed1993

Scintigraphic imaging of MHC class II antigen induction in mouse kidney allografts: a new approach to noninvasive detection of early rejection.

Mice with kidney transplants were investigated to determine whether early kidney allograft rejection could be detected by radioimmune scintigraphy targeting major histocompatibility complex (MHC) class II antigens induced on donor organ cells. Allografts from C3H/He (H2k) donors were transplanted into BALB/c (H2d) recipients. Each mouse was injected intravenously with 100 microCi of 123I-labeled anti-MHC class II monoclonal antibody (mAb; Y17, anti-IEk) 16 h before scintigraphy. After imaging, mice were sacrificed for tissue counting and histopathological examination. Radiotracer uptake in the nontreated allografts increased starting on the 3rd day after transplantation, peaked at around the 6th day, and then gradually decreased. Rejecting allografts with only focal perivascular mononuclear cell infiltration could be identified by scintigraphy. However, allografted mice without evidence of rejection and isografted mice did not show an increase in radiotracer uptake. Rejecting BALB/c kidney transplanted into C3H/He mice did not show an increase in Y17 mAb uptake, suggesting that class II antigens induced on donor kidneys are solely responsible for the mAb uptake in positive scintigrams of rejecting allografts. Five allografted mice were treated with anti-CD3 mAb and cyclosporin starting 3-9 days after transplantation. Radiotracer uptake decreased after 4 weeks of treatment and increased 2 weeks after the cessation of immunosuppressive treatment, reflecting suppression and recurrence of rejection, as determined by histological examination. These changes could be followed scintigraphically. We conclude that changes in class II antigen expression can be assessed by the 123I-labeled anti-MHC class II antigen mAb and that it is a sensitive and noninvasive method for detecting kidney allograft rejection.

Animals↗
PubMed1993

Role of capsaicin-sensitive sensory nerve reflexes in guinea pig model of nasal allergy.

The aim of this study was to examine the pathophysiological role of capsaicin-sensitive sensory nerves in an animal model of nasal allergy. In ovalbumin (OA)-sensitized guinea pigs, a significant increase in nasal total airway resistance (TAR) was noted for at least 180 min after topical antigen challenge. The TAR response to antigen challenge was significantly inhibited for 120 min by general capsaicin pretreatment (167 +/- 12.1 vs. 113 +/- 5.0%, p < 0.001, and 186 +/- 14.9 vs. 119 +/- 6.6%, p < 0.001, control vs. capsaicin pretreatment group at 20 and 90 min after challenge, respectively). However, TAR was significantly though slightly affected even after general capsaicin pretreatment. Following nasal capsaicin challenge, TAR increased for 90 min, and nasal secretion for 30 min. Both the TAR and secretory responses to nasal capsaicin challenge were significantly greater in OA-sensitized guinea pigs than in nonsensitized animals (171 +/- 12.1 vs. 137 +/- 7.4% at 30 min, p < 0.05, and 82.3 +/- 8.6 vs. 13.4 +/- 1.7 mg/10 min, p < 0.05, TAR and secretory response to 300 microM nasal capsaicin challenge, respectively). These results suggest that capsaicin-sensitive sensory nerve reflexes play an important role in the occurrence of early-phase nasal symptoms following topical antigen exposure and are accelerated in OA-sensitized guinea pigs.

Airway Resistance↗
PubMed1993

Acetazolamide test in detecting reduced cerebral perfusion reserve and predicting long-term prognosis in patients with internal carotid artery occlusion.

In a series of 32 patients with internal carotid artery occlusion, regional cerebral blood flow (rCBF) and regional cerebral vasoreactivity (rCVR) were measured by xenon-133 single photon emission computed tomography and the acetazolamide test. We evaluated its usefulness in detecting the reduced cerebral perfusion reserve and predicting long-term prognosis. All Type 1 patients (normal rCBF and rCVR) were medically treated and experienced no recurrent ischemic attack. Cerebral hemodynamics remained unchanged. Type 2, 3, and 4 patients underwent superficial temporal artery-middle cerebral artery double anastomosis, if they consented to surgery. All Type 2 (normal rCBF and reduced rCVR) and Type 3 (reduced rCBF and rCVR) patients, who underwent surgery, showed no further ischemic attacks, as well as long-term normalization of rCVR, although long-term rCBF normalization was obtained in only three of seven Type 3 patients. Cerebral hemodynamics remained unchanged in Type 4 patients after surgery. In follow-up periods, major completed stroke occurred in all 3 Type 2 and Type 3 patients who were medically treated. These results suggest that the acetazolamide test is valuable in assessing the cerebral perfusion reserve and predicting long-term prognosis in patients with internal carotid artery occlusion, although further long-term or randomized studies are needed.

Acetazolamide↗
PubMed1993

Detection of cardiac rejection in mice by radioimmune scintigraphy using 123iodine-labeled anti-ICAM-1 monoclonal antibody.

Intercellular adhesion molecule-1 (ICAM-1) is induced on allograft cells in association with acute rejection and plays important roles in the rejection process. Mice with abdominal heart transplants were studied to determine whether an increase in ICAM-1 expression in rejecting cardiac allografts could be detected by radioimmunoscintigraphy. Allografts from BALB/c donors were transplanted into C3H/He recipients (n = 7). Two of the allografted mice were treated with FK506 (2 mg/kg/day) and four isografted C3H/He mice served as controls. One to eight days after transplantation each mouse was injected intravenously with 50 microCi of 123I-labeled anti-ICAM-1 monoclonal antibody (YN1/1.7). After imaging the mice were killed for tissue counting and histopathology. Graft to native heart radiotracer uptake ratio in the mice with rejecting cardiac allograft (2.12 +/- 0.22, n = 5) was significantly greater than that in the mice with non-rejecting graft (1.23 +/- 0.14, n = 6, p < 0.001). In contrast to non-rejecting grafts, a rejecting allograft with lymphocyte infiltration but without myocyte necrosis and other allografts with relatively advanced rejection could be identified by the scintigraphy. We conclude that 123I-labeled anti-ICAM-1 antibody imaging is a noninvasive method for detecting cardiac allograft rejection.

Abdomen↗
PubMed1993

[A case report of acute mid-graft occlusion of the left internal mammary artery to the left anterior descending artery after PTCA].

A 66 year-old woman underwent coronary artery bypass grafting for postinfarction angina. A left internal mammary artery graft was joined to the left anterior descending artery. Coronary and graft angiography revealed a 90% stenosis in the anastomotic site of the left internal mammary artery. During PTCA with a 2.0 mm balloon catheter, acute occlusion of the graft body occurred. Intragraft injection of isosorbide dinitrate failed to dilate the graft. Thus, careful consideration should be given to several complications such as acute occlusion of the graft when PTCA for anastomotic site of the graft is performed.

Acute Disease↗
PubMed1992

Molecular cloning and chromosomal mapping of a human protein-tyrosine phosphatase LC-PTP.

We isolated cDNA clones encoding a protein-tyrosine phosphatase (PTP) from a human T cell PEER cDNA library. The predicted open reading frame encodes a approximately 40-kDa protein composed of 360 amino acids and has no apparent hydrophobic segments, suggesting that it is a nontransmembrane PTP, which was designated as LC-PTP (leukocyte PTP). Northern blot analysis revealed that the LC-PTP mRNA was preferentially expressed in a variety of hematopoietic cells and the transcriptional sizes were approximately 4.0 kilobases and approximately 2.9 kilobases. Fluorescent in situ hybridization revealed that the human LC-PTP gene is located on the chromosome region 1q32.1, which is known to be a site associated with chromosomal deletion in malignant lymphomas, where candidate tumor suppressor genes might be present.

Amino Acid Sequence↗