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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 973 records · Page 54Linked to original sources
PubMed1989

An autopsy case of myelodysplastic syndrome (MDS): diagnostic problems between MDS and the other haematopoietic disorders including acute myelofibrosis.

We report an autopsy case of myelodysplastic syndrome (MDS) in a 35-year-old male, who presented with pancytopenia and bleedings. Bone marrow specimens disclosed myelofibrosis and hypercellular marrow with more than 60% atypical erythroblasts in the bone marrow cells. Type I or type II blasts were less than 10% of the peripheral blood and bone marrow cells during the clinical course. At autopsy, infiltration by myeloid and erythroid cells and megakaryocytes was noted in the liver, spleen and lymph nodes. According to the FAB classification, this case might be classified into refractory anemia with excess of blasts (RAEB) or RAEB in transformation. However, the remarkable neoplastic proliferation of three haematopoietic cell lines also indicates acute myeloproliferative disorder such as acute myelofibrosis or acute panmyelosis.

Acute Disease↗
PubMed1989

[Surgical procedure and adjuvant therapy in breast cancer].

Modified radical mastectomy (Auchincloss or Patey) have been generally performed for early breast cancer. And this method has shown better prognosis compared with standard (Halsted) or extended radical mastectomy. Also minor conservative surgery (breast or nipple preserving procedure) with or without radiation has been recently tried in small groups of Japan. Postoperative adjuvant chemotherapy (FEMP) has been used in patients proved histologically vascular invasion of cancer cells in our department. Postoperative radiotherapy were undertaken in patients with 4 or more positive axillary nodes or positive parasternal and supraclavicular nodes. Extended radical mastectomy is considered as a favorable method to improve the disease-free survival of the patients with advanced breast cancer, including the combination of chemotherapy, endocrine therapy and radiotherapy. It is important that surgical procedures for breast cancer should be selected and conducted along with a multimodal treatment according to stage for a case by case under the concept of "systemic disease".

Breast Neoplasms↗
PubMed1989

[Studies of IgG subclasses of anti-erythrocyte antibodies contained in human plasma preparation products].

Anti-A and anti-B antibodies (1: 1-1: 1, 024) of IgM or IgG type of the titers 1: 1-1: 1, 024 were detected in all of the lots of heat-treated human plasma protein (38 Lots), albumin (15 Lots), factor VIII or IX products (9 Lots) and immune globulin preparations for intravenous use (IVIG) (20 Lots) examined. Twelve out of 20 lots of IVIG contained unexpected anti-erythrocyte antibodies of IgG type. Though IgG1 antibody was detected in all of these 12 lots, antibodies composed of all subclasses including IgG3 could be detected in only 8 lots of them, all showing the anti-erythrocyte antibody titer of IgG type over 1:64. Conversely, none of the lots, in which the titer was less than 1:32, contained IgG3 antibodies. A patient of chronic ITP, 28-year-old female of blood type A and Rh-positive, showed contradictive results between the main (A type) and the accessory test (O type) of red blood cell grouping, accompanied with hemolytic anemia, following intravenous high-dose immune globulin therapy (400 mg/kg x successive 5 days), which was attributable to the anti-A antibody of IgG type composed of IgG1,2,3,4 in the IVIG administered. For high dosage administration of human plasma preparation products, those containing only low titer of unexpected anti-erythrocyte antibody should be selected.

Adult↗
PubMed1988

Importance of folded monomer and extended antiparallel dimer structures as enkephalin active conformation. Molecular dynamics simulations of [Met5]enkephalin in water.

Simulations of the molecular dynamics of the [Met5]enkephalin monomer and dimer structures in water have been carried out. The dynamic trajectories have been analyzed in terms of the distances between intra- or intermolecular polar atoms. The time-correlated conformational transitions of an extended monomer structure have been converged into a stationary state among the beta-bend folded forms. However, the dynamics simulation of an extended antiparallel dimer structure has shown no noticeable conformation change. These results imply that both the beta-bend monomer and the extended dimer structures exist together as the fundamental conformation of enkephalins.

Calorimetry↗
PubMed1988

Molecular-dynamics simulations of [Met5]- and [D-Ala2,Met5]-enkephalins. Biological implication of monomeric folded and dimeric unfolded conformations.

To investigate the biologically active conformation of enkephalin, molecular-dynamics simulations were applied to [Met5]- and [D-Ala2,Met5]-enkephalins. The dynamic trajectory of monomeric extended [Met5]-enkephalin was analysed in terms of relative mobility between respective torsions of backbone chain. After 10 ps of the dynamics simulation, the conformational transition was converged into a stationary state among the beta-bend folded forms, where they are stabilized by several intramolecular hydrogen-bond formations. Similar conformational transition was also observed in the dynamics simulation of [D-Ala2,Met5]enkephalin, which is a more mu-receptor-specific peptide than [Met5]enkephalin. The geometrical correspondence between the monomeric enkephalin conformation in the stationary state and morphine molecule (a mu-specific rigid opiate) was surveyed by virtue of the triangular substructures generated by choosing three functional atoms in each molecule, and good resemblances were observed. On the other hand, the dynamics simulation of the antiparallel extended [Met5]enkephalin dimer showed a trajectory different from that of the monomeric one. Two intermolecular hydrogen bonds at Tyr1 (NH3+)...Met5(CO2-) end residues were held throughout the 100 ps simulation, the dimeric structure being consequently kept. The conformational transition of the backbone chains from the antiparallel extended form to the twisted one took place via an intermediate state. Many conformations revealed during the dynamics simulation showed that the relative orientations of each two Tyr1, Gly3, Phe4 and Met5 residues in the dimer are nearly related by a pseudo-C2-symmetry respectively, and both halves of the dimer structure could be further fitted to the monomeric folded enkephalin conformation. The monomeric and dimeric conformations of enkephalin at their stationary states are discussed in relation to the substrate-specificity for mu- and delta-opioid receptors.

Computer Simulation↗
PubMed1988

A possible recognition mode of mRNA cap terminal structure by peptide: cooperative stacking and hydrogen-bond pairing interactions between m7GpppA and Trp-Leu-Glu.

1H-NMR and fluorescence spectroscopic studies on the interaction between the Trp-Leu-Glu and m7GpppA have shown a specific binding mode, in which the pi-pi stacking interaction of the Trp indole ring and the hydrogen-bond pairing of Glu carboxyl side group with 7-methylguanine base are simultaneously formed.

Base Composition↗
PubMed1988

A selective recognition mode of a nucleic acid base by an aromatic amino acid: L-phenylalanine-7-methylguanosine 5'-monophosphate stacking interaction.

The conformation of 7-methylguanosine 5'-monophosphate (m7GMP) and its interaction with L-phenylalanine (Phe) have been investigated by X-ray crystallographic, 1H-nuclear magnetic resonance, and energy calculation methods. The N(7) methylation of the guanine base shifts m7GMP toward an anti--gauche, gauche conformation about the glycosyl and exocyclic C(4')-C(5') bonds, respectively. The prominent stacking observed between the benzene ring of Phe and guanine base of m7GMP is primarily due to the N(7) guarternization of the guanine base. The formation of a hydrogen bonding pair between the anionic carboxyl group and the guanine base further stabilizes this stacking interaction. The present results imply the importance of aromatic amino acids as a hallmark for the selective recognition of a nucleic acid base.

Crystallography↗
PubMed1988

[Characterization of thyroglobulin and thyroid peroxidase activity in patients with functioning thyroid benign tumors].

The content and chemical and immunological properties of thyroglobulin (Tg) and the activity of thyroid peroxidase (TPO) were studied in nodular and extranodular (periphery) thyroid tissue from patients with functioning thyroid tumors (hot nodules). From the present observations, the tumor extracts contained fairly large amounts of Tg, similar to that in the periphery tissue, while the content of Tg was markedly decreased in non-functioning thyroid tumors (cold nodules). The iodine content of Tg was significantly higher in nodular tissue compared with periphery tissue. These observations were in contrast to the results seen in the cold nodules in which hormone synthesis was defective. On the nature of carbohydrate moiety as compared with normal tissue, oligosaccharides of Tg from the periphery tissues changed in a manner similar to that of tumor oligosaccharides. That is, high-mannose type oligosaccharides were markedly decreased whereas multiantennary and unidentified oligosaccharides were increased. These observations were similar to those of non-functioning tumors. The content of sialic acid decreased markedly both in the tumor and periphery tissues. Immunologically, Tg preparations of the tumor and periphery tissue did not show the same affinity to the antibodies, depending on the content of iodine. Therefore, it seems that the contribution of the iodine content and iodo-amino acid has little or no significance in the heterogeneous nature of Tg-immunogenecity. Benign tumors and the periphery tissue were subjected to assay for thyroid peroxidase activity by the method employing guaiacol as the second substrate. The specific activities of the tumors were generally higher than those of periphery tissues, both in functioning and non-functioning benign tumors. In non-functioning carcinoma, on the other hand, TPO activities were lower in tumor portions than in periphery portions. This indicates that non-functioning thyroid carcinomas have a different characteristic.

Adenoma↗
PubMed1988

Conformational characteristics of receptor-selective opioid peptides. 1H n.m.r. and c.d. spectroscopic studies of delta-kephalin and [Val4]morphiceptin.

An investigation on the conformations of highly receptor-selective opioid peptides was carried out to gain further understanding of the structure-activity relationship of endogenous enkephalins. The preferred conformations of a highly mu-selective [Val4]morphiceptin and a highly delta-selective delta-kephalin have been probed by 1H n.m.r. solvent-, concentration- and temperature-dependences of amide protons to take the folded conformations stabilized by an intramolecular hydrogen bond and the anti-parallely extended dimeric structures respectively. Their possible stereo-conformations were proposed, based on the analyses of the vicinal coupling constants (JHNC alpha H). The conformational difference between the mu- and delta-selective opioid peptides was further ascertained by the c.d. measurements. The c.d. spectra of the mu-selective peptides show negative bands in the range of 210-230 nm, while those of the delta-selective ones show the opposite positive bands. A correlation between c.d. spectra and receptor-selectivity was possible.

Circular Dichroism↗
PubMed1988

Interaction of protein with a self-associating ligand. Deviation from a hyperbolic binding curve and the appearance of apparent co-operativity in the Scatchard plot.

We derived a general formula to analyze a binding system in which a ligand self-associates, in terms of experimentally determinable quantities, i.e. r, the average number of bound ligands per protein molecule, and Lft, the total free ligand concentration, which are expressed as a ligand monomer unit. The limiting behaviors of the Scatchard plot (r/Lft vs r plot), that is, the intercepts on the r-axis and the r/Lft-axis, and the limiting slopes, are generally given. Three models that may be encountered are considered in detail. Numerical examples are also presented to illustrate how the self-association of a ligand affects the binding curves. The ligand self-association alone can cause deviation of the profile of the binding curve (r vs Lft plot) from a hyperbola, resulting in a nonlinear Scatchard plot. Therefore, analysis of the binding data without consideration of ligand self-association may lead to erroneous conclusions as to the numbers and classes of binding sites, co-operativity among the sites and binding parameter values.

Allosteric Regulation↗
PubMed1988

Effect of desynchronized inputs on compound sensory and muscle action potentials.

Stimulation of the second (S1) or third (S2) digit elicits a median sensory potential at the wrist. Similarly, a shock applied to the median (Sm) or ulnar (Su) nerve at the wrist evokes a sensory potential of the fourth digit and a muscle potential over the thenar eminence. Hence, a concomitant application of S1 and S2 or Sm and Su with varying interstimulus intervals simulates the effect of desynchronized inputs. In 10 hands, a shift in latency on the order of 1 msec between S1 and S2 or Sm and Su caused a major reduction in sensory potential by as much as 30-40% but little change in muscle action potential. A latency difference slightly less than one-half the total duration of unit discharge maximized the phase cancellation between the two components and consequently the loss of area under the waveform.

Action Potentials↗
PubMed1988

Chest wall resection and reconstruction for locoregionally advanced or recurrent breast cancer.

Ten patients, including 7 with local recurrent breast cancer, 2 with primary advanced cancer and 1 with radionecrosis, underwent chest wall resection and immediate reconstruction, using large pedicled skin flaps or musculocutaneous flaps. A rectus abdominis musculocutaneous flap was used in 4 cases and a latissimus dorsi musculocutaneous flap was used in 1 case. The postoperative course of all the patients was uneventful and there was no incidence of flail chest or respiratory failure. The postoperative performance status and also the quality of life were improved in 9 of the 10 patients. Eight of the 10 patients are presently alive with or without disease, the longest survival time thus far being 8 years.

Adult↗
PubMed1988

Results of surgical treatment of patients with T3 non-small cell lung cancer.

Sixty-one patients with T3 non-small cell lung cancer were surgically treated in our department from February, 1974, through April, 1986. The overall 5-year survival, excluding patients with pleurisy, was 23%, and the 5-year survival for patients undergoing complete resection and incomplete resection was 42% and 10%, respectively (p less than 0.01). Survival in patients with T3 N0 and T3 N1 or N2 disease was 33% and 0 at 5 years, respectively. The prognosis for patients with pleurisy was poor, and all died within 3 years. Therefore, complete lung resection should be done in patients with T3 N0 non-small cell lung cancer if complete resection is expected. Long-term survival is less likely for patients with lymph node metastases if complete resection cannot be performed.

Adult↗