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Biomedical subjects

S Noji

Publications and source records attributed to S Noji.

At least 109 records · Page 6Linked to original sources
PubMed1994

Changes in erythrocyte deformability in normal pregnancy and pregnancy-induced hypertension, as revealed by electron spin resonance.

To study changes in hemorheologic properties during pregnancy, erythrocyte deformability was measured by an electron spin resonance (ESR) method. The results obtained by this method showed that erythrocyte deformability in normal pregnancy decreased significantly in the first trimester compared with nonpregnant controls, and continued to decrease slightly as pregnancy progressed. On the other hand, erythrocyte deformability in severe pregnancy-induced hypertension (PIH) was significantly lower than that in the third trimester of normal pregnancy. Additionally, we found that the hematocrit level needed for erythrocytes to exhibit high deformability is lower during pregnancy. These results suggest that hemodilution in normal pregnancy, so-called hydremia, compensates for the decrease in erythrocyte deformability. Conversely, since erythrocytes become less deformable in a hemoconcentration condition in severe PIH, microcirculatory disturbance of various organs, including the uteroplacental unit, may occur. The lowered erythrocyte deformability may be one of the important pathologic features in PIH.

Blood Viscosity↗
PubMed1994

Unique intronic variations of HLA-DQ beta gene in early-onset periodontitis.

Human leukocyte antigen (HLA) class II beta chain plays an important role in the recognition of foreign antigens in immune reactions. Different forms of immune reaction may be concerned with initiation and progression of infectious diseases such as periodontitis. In this study we examined the frequency of HLA class II serotype and the variation of HLA class II beta gene in periodontitis patients. HLA serotypic frequencies in 70 Japanese patients with periodontitis and 26 individuals with periodontal health were examined. No HLA serotype specific to any type of periodontitis was observed. In order to detect differences among some HLA serotypes, restriction fragment length polymorphism (RFLP) analysis was undertaken with cDNA probes for HLA-DR beta and HLA-DQ beta genes in 20 subjects (15 patients and 5 healthy individuals). Atypical BamHI and EcoRI restriction sites were found in the HLA-DQ beta gene from 3 patients with early-onset periodontitis. In addition to these 20 subjects, an additional 80 subjects (40 patients and 40 healthy individuals) were screened for the atypical BamHI restriction site using the polymerase chain reaction method. It was detected in 7 patients with early-onset periodontitis, 1 patient with adult periodontitis, and 3 healthy subjects. No clinical differences except age were found between patients with this gene variation and other patients. Interestingly, all 3 healthy subjects with this gene variation were from subjects whose family members developed early-onset periodontitis with the gene variation. Atypical BamHI and EcoRI restriction sites and 41-nt repeated sequence were found in the intron before the third exon of HLA-DQB gene. These results suggest that these intronic gene variations may be useful as gene markers for a subpopulation of early-onset periodontitis and might affect immune reactions such as antigen recognition.

Adolescent↗
PubMed1994

[Free arterial graft for coronary bypass grafting].

Free arterial grafts were aggressively placed in 39 patients (1991 to 1993). There were 34 males and 5 females, and mean age was 59.9 year old. Of 85 arterial grafts, 41 were free grafts, and their materials included left and right internal thoracic artery (LITA, RITA) and right gastroepiploic artery (GEA). There were one free LITA-left anterior descending coronary artery (LAD), seven free RITA-LAD, three free RITA-diagonal branch (Dx), 14 free RITA-left circumflex coronary artery (LCX), 10 free RITA-right coronary artery (RCA), two sequential RITA-Dx-LCX, one free GEA-Dx, two free GEA-LCX, and one free GEA-RCA bypass. Of 41 free arterial grafts, 38 were in the aorta-coronary position, and the proximal anastomosis was constructed first under single aortic cross-clamping to get the larger anastomotic sites for both at the proximal and distal ends of the arterial graft. The proximal sites of the remaining 3 arterial grafts were placed to concomitantly utilized saphenous vein grafts in two patients and RCA in one patient because of their shortness. Perioperative complications included no exploration for bleeding, myocardial infarction in one (2.6%), intra-aortic balloon pumping in three (7.7%), and wound complications in two (5.1%). 28 cases (72%) were completely revascularized with only arterial grafts. Of 41 free arterial grafts studied within one month after operation, all grafts were patent. All patients were free from angina after a 27 months mean follow-up. We believe that the proximal anastomosis technique for free arterial graft we used could be acceptable alternative for many surgeons. These excellent results justify wider use of free arterial grafts.

Abdominal Muscles↗
PubMed1993

A novel class of murine POU gene predominantly expressed in central nervous system.

A mouse gene (referred to as Emb) encoding a novel class of POU domain is described. The Emb POU domain shares only 40-50% homology to that of any other POU proteins. Nonetheless, the Emb POU domain can bind to the octamer sequence like other POU domains. Emb is a single-copy gene, located on the distal region of mouse chromosome 15. It is expressed in embryo throughout post-implantation stages, where the most prominent expression is seen in developing central nervous system. In the adult, it is highly expressed in brain, whereas weaker expression can be detected in other organs such as testis, skeletal muscle, and kidney. The expression in adult brain is most evident in neurons of hypocampus formation. Two types of Emb mRNA are expressed in brain; one type encodes a protein of 301 amino acids residues, whereas the other codes for a protein with two extra amino acids residues added at the amino-terminal end of POU domain. These two mRNA species are generated by alternative splicing by utilizing an unusual splice acceptor site: CCTCCCTCTG/. Emb mRNA expressed in testis, on the other hand, encodes a smaller protein lacking most of the amino-terminal region.

Amino Acid Sequence↗
PubMed1993

A chicken homeobox gene related to Drosophila paired is predominantly expressed in the developing limb.

We identified a homeobox-containing gene, Prx-1, isolated from the chick limb bud cDNA library. The homeodomain sequence is related to Drosophila paired and goose-berry and mouse Pax-3, Pax-6, and Pax-7. The deduced amino acid sequence of the Prx-1 gene product reveals the absence of a paired-box sequence and extensive similarity to mouse S8 and MHox homeodomain proteins, thus constituting a new class of homeobox gene. Using an in situ hybridization method, the Prx-1 gene is shown to be expressed predominantly in the limb bud and visceral arches. At early stages of limb development, distal mesodermal cells express the homeobox gene with an apparent gradient along the proximal-distal axis. The signal is absent in the apical and nonridge ectoderm. Removal of the apical ectodermal ridge had no apparent effect on the subsequent expression of Prx-1 in the limb mesenchyme. The Prx-1-expressing cells are later confined to the interdigital and perichondrial regions. The Prx-1 transcripts are also detectable in the mesenchyme of the visceral arches and facial primordia subjacent to the ectoderm. The Prx-1 gene is weakly expressed in somites and condensing vertebrae. No signal is detectable in neural tube and ectodermal epithelium. These results suggest that the Prx-1 homeodomain protein is involved in the differentiation of bone, muscle, and other tissues of mesodermal origin during limb development.

Amino Acid Sequence↗
PubMed1993

MRC-5, human embryonic lung fibroblasts, induce the duplication of the developing chick limb bud.

The anteroposterior (A-P) axis pattern of the chick limb is likely to be controlled by a small region of mesenchyme cells at the posterior margin of the limb bud (ZPA, zone of polarizing activity). In this study, we found that MRC-5 fibroblast cells had the capacity for duplicated-pattern formation of the chick limb along the A-P axis when grafted to the anterior region of the limb bud. MRC-5 cells were effective only during pre-limb bud stages, and the leg bud was more responsive than the wing bud. Grafted cells remained at the base of the limb bud when limb development proceeded. These results suggest that the products of MRC-5 cells are involved in three possible processes of duplicated-pattern formation: induction of the polarizing activity; maintenance of this activity, which is present weakly at pre-limb bud stages; and determination of A-P axis as the ZPA factor(s). By allowing the use of a small number of cells of embryonic tissues with polarizing activity, the analysis of duplicate formation with the MRC-5 cell line provides a powerful tool for elucidating the molecular nature of the ZPA.

3T3 Cells↗
PubMed1993

Responsiveness to retinoic acid changes during chondrocyte maturation.

We previously showed that retinoic acid (RA) participates in the regulation of chondrocyte maturation during endochondral ossification, a process involving multiple developmental stages. To assess whether the responsiveness to RA treatment changes during chondrocyte maturation, immature chondrocytes were isolated from the caudal portion of Day 18-19 chick embryo sterna, a portion that remains cartilaginous through early postnatal life but ossifies with age. The immature cells were allowed to reach different stages of maturation by growth for different time in culture. Progression by the cells toward the mature phenotype during culture was confirmed by increases in average cell diameter, proteoglycan synthesis, and alkaline phosphatase (APase) activity. When developmentally immature passage 0 (PO) cultures were treated with RA (10-100 nM) for 72 h, the cells readily became fibroblastic, reduced drastically their proteoglycan synthesis, and failed to activate type X collagen gene expression. When older cultures (P1 and P2) were treated with RA, the cells acquired a characteristic epithelioid shape and increased their APase activity. Moreover, 5-10% of P1 cells and 20-25% of P2 cells activated type X collagen synthesis in response to RA. RA treatment markedly induced expression of the gene encoding the beta isoform of retinoic acid receptor (RAR beta) and also provoked a moderate 2.5-fold increase in RAR alpha gene expression. A similar change in responsiveness to RA was observed during maturation in vivo. Chondrocytes were isolated from the cephalic portion of Day 10, 11, 13, and 16 chick embryo sterna, and were treated with different doses of RA (10-100 nM) for 72 h. The cells from the Day 10 sternum failed to activate type X collagen gene expression in response to RA. In contrast, with increasing age of the embryos, an increasing fraction of cells induced type X collagen gene expression in response to RA. We conclude that responsiveness to RA changes during the early stages of chondrocyte maturation and that maturation depends on interactions between exogenous retinoids and the endogenous developmental program of chondrocytes.

Alkaline Phosphatase↗
PubMed1993

A mutation in the Pax-6 gene in rat small eye is associated with impaired migration of midbrain crest cells.

The rat small eye strain (rSey) lacks eyes and nose in the homozygote, and is similar to the mouse Sey strain with mutations in the Pax-6 gene. We isolated Pax-6 cDNA clones from an rSey homozygote library, and found an internal deletion of about 600 basepairs in the serine/threonine-rich domain. At the genomic level, a single base (G) insertion in an exon generates an abnormal 5' donor splice site, thereby producing the truncated mRNA. Anterior midbrain crest cells in the homozygous rSey embryos reached the eye rudiments but did not migrate any further to the nasal rudiments, suggesting that the Pax-6 gene is involved in conducting migration of neural crest cells from the anterior midbrain.

Alternative Splicing↗
PubMed1993

Nucleotide sequence of a cDNA encoding the chicken receptor protein kinase of the TGF-beta receptor family.

We have isolated RPK-2 cDNA from chick embryo cDNA library that encodes a receptor protein kinase of the TGF-beta receptor subfamily. The deduced amino acid sequence reveals the presence of a hydrophobic transmembrane helix and a kinase domain distantly related to type II receptor for TGF-beta. The kinase domain sequence is most similar to RPK-1 identified recently in the chick embryo. Several cysteine residues are contained in the amino-terminal ectodomain, suggesting the protein as a receptor for a peptide growth factor of the TGF-beta family.

Amino Acid Sequence↗
PubMed1993

Cooperative activation of Chox-4 homeobox genes by factors from the polarizing region and the apical ridge in chick limb morphogenesis.

When a mouse zone of polarizing activity (ZPA) at the posterior margin of the limb bud was grafted at the anterior margin of the chick limb bud, we found that expression of the chick homeobox genes, Chox-4.7 and -4.8, was induced prior to the formation of chick extra digits. The induction was observed in the restricted domain close to both grafted mouse ZPA and the chick apical ectodermal ridge (AER). When the posterior half of the AER was removed, the normal expression was diminished in the posterodistal region. Thus, it is likely that at least two distinct factors, one from the ZPA and the other from the AER, provide positional information to induce cooperatively the sequential expression of the Chox-4 genes.

Animals↗
PubMed1993

Differential expression of three chick FGF receptor genes, FGFR1, FGFR2 and FGFR3, in limb and feather development.

Expression patterns of three fibroblast growth factor receptor genes, FGFR1 (cek1), FGFR2 (cek3) and FGFR3 (cek2), were observed in limb and feather morphogenesis. Expression of FGFR1 was observed in the mesoderm of limb bud, in the mesenchyme just underneath the feather placode, and then in the anterior mesenchyme of the feather bud. While expression of FGFR2 was observed in both surface ectoderm and mesenchymal aggregates corresponding to the future bones of the limb, the mesenchyme between the feather placode, and surface ectoderm of feather buds. Expression of FGFR3 was observed rather ubiquitously over mesoderm of limb and feather buds. Differential expression of these FGF receptor genes suggested that differential roles of these receptors in epithelia-mesenchymal interactions of limb and feather morphogenesis.

Animals↗
PubMed1993

Expression patterns of the activin receptor IIA and IIB genes during chick limb development.

Activin is known to induce axial mesoderm during early development in Xenopus embryo. Activin receptor was recently identified to be a member of transmembrane serine/threonine kinase family. We have studied the role of activin-mediated signaling in the limb morphogenesis by identifying the target cells. We isolated cDNAs encoding chicken activin receptors, cARIIA and cARIIB, and examined their expression patterns during chick embryogenesis. The cARIIA gene is expressed in the apical ectoderm of the limb bud at stage 20-21, whereas the cARIIB gene is expressed uniformly in the limb mesenchyme. Expression of the cARIIA gene is confined to dorsal and ventral mesenchyme at stage 23, and later confined to precartilaginous cells. Transcripts of the cARIIA gene are found in developing neuroepithelium of spinal cord, brain and eye, surface ectoderm differentiating to epidermis, and myoblasts differentiating to muscle. The IIB receptor gene is highly expressed in the developing brain. These results suggest that the activins and their receptors are implicated in the limb development, especially, in differentiation of muscle, skin and bone.

Activin Receptors↗
PubMed1993

Studies on phosphorylated transcriptional regulator (NarL) for E. coli nar operon by 31P-NMR spectroscopy.

The sequential transphosphorylation from autophosphorylated nitrate-sensing protein (NarX) to the transcriptional regulator protein (NarL), both operating in signal transduction to control the expression of the respiratory nitrate reductase (nar) operon in E. coli, was demonstrated with an in vitro reconstructed system to function similarly to other bacterial two-component regulatory systems. Over-expression system established by means of the pT7 promoter/polymerase provided both NarX and NarL proteins to reconstruct the in vitro transphosphorylation system. The phosphorylated NarL was detected, and the unstable phosphorylated group was directly assigned to acyl phosphate in the in vitro system by 31P-NMR spectroscopy.

Autoradiography↗
PubMed1993

[A successful repair of tetralogy of Fallot with aortic valve regurgitation, coronary artery-pulmonary artery fistula and absent pulmonary valve in a 54-year-old man].

A 54-year-old man suffered from tetralogy of Fallot associated with aortic valve regurgitation, coronary artery-pulmonary artery fistula and absent pulmonary valve underwent intracardiac repair. The operation was completed with ligation of the fistula, aortic valve replacement using a SJM 27 A, patch closure of ventricular septal defect (perimembranous outlet type) and right ventricular outflow reconstruction using a large transannular monocusped-patch, 4 cm x 6 cm in size. Postoperative course was uneventful and he is doing well now. There was no previous reports about TOF associated with AR, the absent pulmonary valve and the coronary anomaly in the adults in the literature.

Aortic Valve Insufficiency↗
PubMed1993

[Autotransplantation as optimal technique for recurrent malignant myxoma of left ventricle].

Application of autotransplantation for left ventricular recurrent malignant tumor which was considered to be originating from the posterior leaflet of mitral valve was presented. A patient was 29 year-old-female and underwent the resection of tumor. The tumor was resected en bloc with the mitral valve, and its histology was myxoma. But she was required reoperation two times because of the recurrence of the tumor unfortunately. The tumor was ultimately diagnosed as the myxofibrosarcoma with chondroid differentiation. At the time of the third surgery, the heart transplantation was thought to be only treatment for radicality. While sounding American counterparts on the possibility of the heart transplantation, her condition took a sudden turn for the worse. An autotransplantation technique was applied for the resection of the tumor emergently. As a result, it was impossible to completely resect the tumor because of severe invasion to the left ventricle, and the patient died suddenly on the 75th day after the operation due to fetal arrhythmia. Through this case, heart transplantation should be considered for such a case, but autotransplantation technique allowed to be a life-prolonging in this case. We believe that this technique which will be obtained the excellent operative field could be used for repair of complex cardiac anomalies and rupture of left ventricle and so on.

Adult↗