Search PubMed⌕ Search

Biomedical subjects

Y Matsui

Publications and source records attributed to Y Matsui.

At least 235 records · Page 13Linked to original sources
PubMed1996

[Subtotal aortic replacement in a patient with Marfan's syndrome--replacement of the ascending aorta and entire aortic arch for acute type I aortic dissection 4 years after the thoracoabdominal replacement].

We report a patient with Marfan's syndrome who underwent replacement of the ascending aorta and the entire aortic arch for acute type I aortic dissection 4 years after the thoracoabdominal replacement. As a result, she underwent subtotal aortic replacement from the ascending aorta to the bilateral common iliac arteries in three stages. A 48-years-old female was admitted to our service because of acute heart failure and cardiogenic shock caused by acute DeBakey type I aortic dissection. She had undergone replacement of the descending thoracic aorta at the age of 44 and replacement of the remaining thoracoabdominal aorta with reimplantation of the four major abdominal branches at the age of 46 for a chronic expanding DeBakey type IIIb dissecting aneurysm. She successfully underwent replacement of the ascending aorta and the entire aortic arch with an aortic prosthesis provided with four branch grafts for reconstruction of the arch vessels. Considering the high incidence of new aortic lesion, extensive aortic replacement and careful postoperative follow-up are necessary in patients with Marfan's syndrome.

Aortic Dissection↗
PubMed1996

[Successful surgical repair of acute DeBakey type I aortic dissection complicated by acute occlusion of the suprarenal abdominal aorta].

We reported a case of acute DeBakey type I aortic dissection presented with occlusion of the suprarenal abdominal aorta, who was successfully treated by simultaneous graft replacement of the ascending aorta and total aortic arch. The patient was a 68-year-old man who complained of chest pain and symptoms of acute arterial occlusion of bilateral lower extremities, and who had consciousness disturbance due to stroke caused by aortic dissection. He underwent simultaneous graft replacement of the ascending aorta and total aortic arch under selective cerebral perfusion during an emergent operation. For reconstruction of the arch vessels, we used three separate grafts that were connected to the aortic prosthesis before use. Although postoperative course was complicated by myonephropathic metabolic syndrome, the patient subsequently recovered and was discharged on foot. Early vascular reconstruction and appropriate management of reperfusion injury are extremely important in the setting of malperfusion phenomena complicating acute aortic dissection.

Aged↗
PubMed1996

Maternal allergen stimulation suppressed respiratory allergy in offspring: with special reference to allergy related cells in the tonsil.

Pregnant mice and Hartley guinea pigs were immunized with T dependent antigen, heterologous erythrocyte and ovalbumin (OVA), and the active immune responsiveness as well as the allergic symptoms of the offspring were investigated. Guinea pigs were also sensitized to OVA intraperitoneally and subcutaneously with a 100 mg/ml solution of saline containing 5 mg of AI(OH)(3) as an adjuvant. Six weeks after the initial allergen stimulation, systemic and local anaphylaxis as elicited by 1-min aerosol administration of a nebulizer and monitored by macroscopic vision accompanied by a time trial for respiratory and cardiac arrest. Serum antibody levels were tested by passive hemagglutination as well as passive cutaneous anaphylaxis especially for the estimation of IgE levels. Nasal, tonsillar and bronchial tissues were also prepared and fixed, followed by hematoxylin and eosin staining for histological observation. In the offspring of mothers who had been stimulated with optimal amounts of the allergen and had fully developed specific antibodies against the allergen, there was a clear-cut suppression in the development of a specific respiratory allergy over a significant period after delivery. The effect was confirmed by systemic and local anaphylaxis, eosinophil infiltration, ciliary deformation in nasal mucosae and the tonsillar site in the complex interaction of various cell types and mediators eliciting the clinical respiratory symptoms, in particular nasal hypersensitivity. In a different experimental model, the mouse model, these biological findings were not regulated by maternal transferable antibody or antigen fragments from the mother. The induction of suppressor T cell (CD(4+)) in offspring depends on the recognition of the antigens presented in association with the same MHC haplotype as that utilized in the maternal T cell response during pregnancy. These results suggest the presence of suppression mechanisms in the offspring of mothers stimulated during pregnancy. From these results, we discuss the mechanisms for suppression and protective efficacy for respiratory allergy as well as possible side effects in the young of mothers stimulated during pregnancy.

Allergens↗
PubMed1995

Molecular cloning and expression of mouse mg(2+)-dependent protein phosphatase beta-4 (type 2C beta-4).

A full-length complementary DNA (cDNA) clone (pTK-3) encoding an isoform of Mg(2+)-dependent protein phosphatase beta (MPP beta-4) was isolated for the first time from a mouse melanocyte cDNA library. It was strongly suggested that the mRNA corresponding to the pTK-3 insert was a splicing variant of a single pre-mRNA that also encodes MPP beta-1 and -2 (T. Terasawa, T. Kobayashi, T. Murakami, M. Ohnishi, S. Kato, O. Tanaka, H. Kondo, H. Yamamoto, T. Takeuchi, and S. Tamura, 1993, Arch. Biochem. Biophys. 307, 342-349). The amino acid sequence of MPP beta-4 differed from those of MPP beta-1 and -2 only at the carboxyl terminal region. Analysis by reverse transcriptase polymerase chain reaction (RT-PCR) revealed that MPP beta-4 mRNA was expressed only in testis and intestine and not in other mouse tissues tested. Specific expression of the mRNA signals of two other isoforms of MPP beta, MPP beta-3 and -5 (a novel isoform), in testis and intestine was also demonstrated by the RT-PCR. The carboxyl terminal region of MPP beta-5 was found to have a chimera structure composed of part of MPP beta-1 and part of MPP beta-3. The recombinant MPP beta-3 and -4 and the putative MPP beta-5 expressed in Escherichia coli cells exhibited Mg(2+)-dependent and okadaic acid-insensitive protein phosphatase activities. It was demonstrated that the mRNA expression levels of MPP beta-3, -4, and -5 alter according to the maturation of mouse testis. These results suggest that the complex structure of MPP beta isoforms and their tissue- and developmental stage-specific expression reflect the variety of their physiological functions.

Alternative Splicing↗
PubMed1995

Isolation and characterization of temperature-sensitive plc1 mutants of the yeast Saccharomyces cerevisiae.

The PLC1 gene of the yeast Saccharomyces cerevisiae has been discovered to encode a homolog of mammalian phosphoinositide-specific phospholipase C (PLC). Five temperature-sensitive plc1 mutants were isolated by in vitro mutagenesis with subsequent plasmid shuffling. All of the amino acid substitutions that caused a temperature-sensitive growth phenotype were located in the X or the Y region, both of which are conserved among PLC isoenzymes. The PLC activity of all products of mutant plc1 genes was dramatically lower than that of the wild-type product, indicating that PLC activity itself is important for cell growth. At the restrictive temperature, plc1 mutant cells ceased growth at random times during the cell cycle, a result that suggests that PLC1 is required at several or all stages of the cell cycle.

Amino Acid Sequence↗
PubMed1995

Direct observations of arrangements of carbonate groups in oxycarbonate superconductors by high-resolution electron microscopy.

Arrangements of CO3 groups in various types of oxycarbonate superconductors are examined by high-resolution transmission electron microscopy (HRTEM). Every other B-site of basic perovskite structure is replaced with CO3 groups in the first carbonate superconductor, (Ba0.56Sr0.44)2Cu1.1(CO3)0.9Oy. The 123-related oxycarbonate superconductor obtained in a Y-Ca-Sr-Cu-O system, (Y0.475Ca0.475Sr0.05)Sr2Cu2.4(CO3)0.6Oy, has a superstructure with 2a periodicity due to ordered replacements of Cu-site with CO3 groups. The non-superconducting counterpart with 123-related structure, (Y0.84Sr0.16)2Sr2Cu2.6(CO3)0.4Oy, on the other hand, shows more disordered arrangements of CO3 groups with nearly 3a periodicity. Similar superstructures, due to ordered replacements of Cu sites with CO3 groups, are also observed in the 223-related oxycarbonate superconductors, (Ln,Ce)2Sr2Cu2.5(CO3)0.5Oy (Ln = Ho, Dy). Homologous series of compounds, (CaSr)n+1Cun(CO3)Oy (n = 1-5), consist of alternate stacking of Sr2Cu(CO3)Oy and SrCuO2 (infinite-layer) types of blocks. They become superconductive by additionally doping the BO3 group. Another homologous series of Bi-based oxycarbonate superconductors, (Bi,Pb)2Sr2n+2Cun+1 (CO3)nOy (n = 1-3), contain alternate CuO2 and CO3 layers in between the two (BiO)2 layers. Both mercury (Hg)- and thallium (TI)-based oxycarbonate superconductors, MBa2Sr2Cu2(CO3)Oy (M = Hg or Tl) show quite unique modulation structures, where both HgO (or TlO) and CO3 layers repeat in the same plane, along [110] in the Hg compound and [100] in the Tl compound, to form long-period superstructures with wavy distortion of atom planes.

Carbonates↗
PubMed1995

Murine polo like kinase 1 gene is expressed in meiotic testicular germ cells and oocytes.

To identify key molecules that regulate germ cell proliferation and differentiation, we have attempted to isolate protein kinase genes preferentially expressed in germ line cells. One such cDNA cloned from murine embryonic germ(EG) cells encodes a nonreceptor type serine/threonine kinase and is predominantly expressed in the testis, ovary, and spleen of adult mouse. The nucleotide sequence of the entire coding regions shows that this clone, designated Plk1(polo like kinase 1), is identical with STPK13 previously cloned from murine erythro-leukemia cells. The protein encoded by Plk1 is closely related to the product of Drosophila polo that plays a role in mitosis and meiosis. To define the role of Plk1 in germ cell development, we have examined its expression in murine gonads by in situ hybridization. Here we show that the Plk1 gene is specifically expressed in spermatocytes of diplotene and diakinesis stage, in secondary spermatocytes, and in round spermatids in testes. It is also expressed in growing oocytes and ovulated eggs. The pattern of expression of the Plk1 gene suggests that the gene product is involved in completion of meiotic division, and like the Drosophila polo protein, is a maternal factor active in embryos at the early cleavage stage.

Animals↗
PubMed1995

Molecular cloning of the plc1+ gene of Schizosaccharomyces pombe, which encodes a putative phosphoinositide-specific phospholipase C.

Exploiting the polymerase chain reaction, we have isolated a gene that encodes a putative phosphoinositide-specific phospholipase C (PLC) of the fission yeast Schizosaccharomyces pombe. Inspection of the nucleotide sequence of the gene revealed an open reading frame that can encode a polypeptide of 899 amino acid residues with a calculated molecular mass of 102 kDa. This putative polypeptide contains both the X and Y regions that are conserved among three classes of mammalian PLC, and also contains a presumptive Ca(2+)-binding site (an E-F hand motif). The structure of the putative protein is most similar to that of the delta class of PLC isozymes. To investigate the role of this gene, designated plc1+, gene disruption was carried out by interrupting the coding region with the ura4+ marker. Growth of plc1 cells was temperature-sensitive in rich medium, and cells could not grow in synthetic medium. Expression of the PLC1 gene of Saccharomyces cerevisiae suppressed the growth defect phenotype of plc1- cells, a strong suggestion that the plc1+ gene encodes PLC.

Amino Acid Sequence↗
PubMed1995

Melittin cardiotoxicity in cultured mouse cardiac myocytes and its correlation with calcium overload.

Venom from the honey bee Apis mellifera induces cardiovascular dysfunction. We studied which constituent(s) of the venom induces cardiotoxicity and how, using cultured cardiac myocytes from mouse fetuses. Among the venom constituents, only melittin caused contractile and morphological effects; other peptides, such as apamin and mastparan; enzymes, such as phospholipase A2; and low-molecular-weight compounds, such as histamine and dopamine, did not. Treatment with 4.5 micrograms/ml melittin, which accounts for about half the dry weight of the venom, induced the same cardiotoxic effects as treatment with 9.0 micrograms/ml whole venom; these effects were a transient increase in the spontaneous beating rate, then a decrease, then cessation of beating, and finally, morphological degeneration. The cardiotoxicity of whole bee venom was completely destroyed by pretreatment of the venom with antimelittin antibody. These results suggest that bee venom cardiotoxicity is attributable to melittin. When spontaneous beating ceased following the addition of melittin or whole venom, an increase in systolic [Ca2+]i, was observed. On further incubation with melittin or bee venom, morphological injury, such as balloon degeneration, occurred concomitant with a further increase in the [Ca2+]i. An extracellular Ca2+ concentration of more than 10(-6) M was necessary for morphological injury. Melittin depolarized the maximum diastolic potentials, inhibited the generation of action potentials, and induced an increase in [Na+]i. Cells were protected against the melittin-induced increase in [Ca2+]i by pretreatment with bepridil, an inhibitor of Na(+)-Ca2+ exchange, but not by Ca2+ channel blockers such as verapamil. These observations suggest that the melittin-induced increase in [Ca2+]i was due to entry of extracellular Ca2+ via the sarcolemmal Na(+)-Ca+ exchange system.

Animals↗
PubMed1995

Alterations in coagulation and fibrinolysis after surgery for aortic aneurysm.

We investigated the alterations in the coagulation and fibrinolysis systems after aortic aneurysm surgery under cardiopulmonary bypass (CPB) while using newly developed "molecular markers". Fibrinogen and antithrombin III (AT-III) decreased after surgery but returned to normal values within three days. The thrombin-antithrombin III complex (TAT) and plasmin-alpha-2-plasmin inhibitor complex (PIC) both showed increased values even preoperatively, which indicated that coagulation and fibrinolysis were activated in some patients with an aortic aneurysm. Both markers maintained a high level for at least 14 days after surgery. The fibrin degradation product (FDP) also showed an increased value before and after surgery. These results apparently showed that coagulation/fibrinolysis had already been activated in some patients and maintained such a state for at least 14 days after surgery. The relation of activated system and postoperative organ dysfunction as well as the means to suppress such activation are also discussed.

Aged↗
PubMed1995

Preoperative disseminated intravascular coagulation (DIC) associated with aortic aneurysm--does it need to be corrected before surgery?

Disseminated intravascular coagulation (DIC) is one of the complications accompanying aortic aneurysm. We herein report four patients with aortic aneurysm who had DIC preoperatively. In all four cases, DIC was corrected immediately after surgery; however, in two cases, DIC could not be corrected preoperatively. This prompted us to reconsider the importance of correcting DIC before surgery. Of the four cases reported in this paper, DIC existed even at the time of surgery in two cases, in spite of meticulous treatment with heparin and/or protease inhibitor; however, the DIC could be removed postoperatively even in these two cases. Surgeons should not waste time with intensive DIC treatment preoperatively. If the DIC cannot be corrected within more than 2 weeks of meticulous treatment, surgeons should then perform surgery on the patient. In addition, it is also essential to ensure that the DIC is due to the aneurysm itself and that no other disease processes have been overlooked.

Aged↗
PubMed1995

Prognostic significance of posterior subtalar joint arthrography following fractures of the calcaneus.

Nineteen patients with 22 intra-articular fractures of the calcaneus were investigated by posterior subtalar joint arthrography after 6 (2-15) months following injury, and their clinical symptoms were compared with the arthrographic findings. The arthrograms were classified into four types based on the findings of the joint space of the posterior subtalar joint in Anthonsen's view. The classification correlated significantly (P = 0.03) with the clinical results which were assessed after 23 (9-41) months following injury. We conclude that posterior subtalar joint arthrography has prognostic value in assessing patients with fractures of the calcaneus.

Adolescent↗
PubMed1995

Seronegative myasthenia gravis associated with atonic urinary bladder and accommodative insufficiency.

We report a 20-year-old female with generalized myasthenia gravis (MG) who developed atonic urinary bladder and accommodative insufficiency. Although her sera did not contain antibodies to either nicotinic acetylcholine receptor (AChR) or voltage-gated calcium channels, a positive intravenous edrophonium test and a waning phenomenon on electromyographic studies indicated a diagnosis of seronegative MG. Myasthenic symptoms as well as urinary incontinence and impaired near vision disappeared with slight sequelae after corticosteroid therapy and total removal of the hyperplastic thymus. These symptoms recurred during a tapering course of corticosteroids, and improved again with an increased dose. Therefore, in this patient, the neuromuscular transmission of muscarinic type of AChR in the smooth muscles was also affected. This patient provides insight into the mechanisms by which some smooth muscles are involved in MG.

Accommodation, Ocular↗