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Biomedical subjects

S Noji

Publications and source records attributed to S Noji.

At least 127 records · Page 7Linked to original sources
PubMed1992

Expression pattern of the activin receptor type IIA gene during differentiation of chick neural tissues, muscle and skin.

To elucidate target cells of activins during embryogenesis we isolated cDNAs of chick activin receptor type II (cActR-II) and studied expression patterns of the cActR-II gene by in situ hybridization. Transcripts of cActR-II were observed in neuroectoderm developing to spinal cord, brain and eyes, in surface ectoderm differentiating to epidermis, and in myotomes differentiating to muscles. The expression patterns of cActR-II suggest that activin and its receptor are involved in differentiation of chick neural tissues, muscle and skin after inducing the dorsal mesoderm.

Activin Receptors↗
PubMed1992

Differential expression of two msh-related homeobox genes Chox-7 and Chox-8 during chick limb development.

We have isolated two closely related cDNAs, Chox-7 and Chox-8, encoding homeodomain-containing proteins homologous to Drosophila msh. The Chox-7 and Chox-8 genes are chicken cognates of mouse Hox-7.1 and Hox-8.1, respectively. In situ hybridization using 3' regions of the cDNAs as probes revealed that the Chox-7 gene is highly expressed in the mesenchyme subjacent to the apical ectodermal ridge whereas Chox-8 expression is localized in the anterodistal mesenchymal region at early stages of limb formation, suggesting different roles during limb development. At later stages, both genes are expressed in the anterior and posterior mesenchymes and in the interdigital mesenchyme where programmed cell death occurs.

Amino Acid Sequence↗
PubMed1992

Rapid and marked induction of hepatocyte growth factor during liver regeneration after ischemic or crush injury.

Liver injuries induced by ischemia or physical trauma are characterized by noninflammatory damage frequently observed in a clinical setting. When the liver of rats was injured by ischemic treatment or physical crushing, necrotic tissue degeneration occurred in several sites of lobulus within 24 hr. Hepatocyte growth factor, a potent mitogen for adult rat hepatocytes in primary culture, was markedly induced in the livers of rats injured by ischemia or physical trauma. In both cases, the hepatocyte growth factor messenger RNA level in the injured liver reached about 10 to 20 times that of the normal level during 12 to 24 hr after liver injury. The increase in hepatocyte growth factor messenger RNA correlated well with the degree of liver damage as evaluated by serum ALT activity in the sera of rats. In situ hybridization showed that hepatocyte growth factor messenger RNA expression occurs in nonparenchymal liver cells, primarily in Kupffer cells of the ischemic liver. After the increase of hepatocyte growth factor messenger RNA in the injured liver, a marked compensatory hepatocyte DNA synthesis occurred 48 to 72 hr after these treatments. These results suggest that hepatocyte growth factor acts as a hepatotropic factor for liver regeneration after noninflammatory liver damage caused by ischemia and physical crush, probably through a paracrine mechanism.

Animals↗
PubMed1992

Morphogenetic roles of retinoic acid.

We integrated our information on morphogenetic roles of retinoic acid, focusing on development of chick limb. Retinoic acid has been considered to be a putative morphogen released from the ZPA. However, since exogenous retinoic acid induces expression of RAR beta, but not grafted ZPA, the ZPA is unlikely to produce retinoic acid. From the result that retinoic acid-treated cells induce digit duplication, retinoic acid converts anterior cells into ZPA cells. We found that retinoic acid also induces expression of homeobox genes indirectly and that bFGF enhances expression of the homeobox genes. Thus, we considered that retinoic acid and growth factors cooperate with each other to activate homeobox genes. A morphogenetic role of retinoic acid is to coordinate developmental stage of each cells by controlling expression of homeobox genes.

Animals↗
PubMed1992

[In situ hybridization histochemistry for the kidney diseases].

Crucial points of in situ hybridization methods were pointed out for study on the kidney diseases at molecular level. As examples of in situ hybridization study on kidney, we introduced two cases: 1) expression of the hepatocyte growth factor gene during renal regeneration after unilateral nephrectomy, and 2) induction of the metallothionein gene expression by ischemic acute renal failure. We proposed an idea to establish a probe bank for the in situ hybridization study.

Acute Kidney Injury↗
PubMed1992

[A clinical assessment of efficacy in continuous retrograde cerebral perfusion method].

From November 1990 to June 1991, 8 patients underwent surgical repair using continuous retrograde cerebral perfusion (CRCP). We evaluated the effect of CRCP from these 8 cases. As a method of CRCP, we perfused with oxygenated blood from SVC canulae with a internal jugular vein pressure of 30-40 cmH2O. Simultaneously systemic perfusion from femoral arterial canulae was performed. At nasopharyngeal temperature of 15-21 degrees C, CRCP time was 46-115 minute. SVC perfusion flow was 280-900 ml/min, and femoral arterial perfusion flow was 450-1,200 ml/min. At 30 minute after starting CRCP, oxygen tension of the blood which was returned to aortic arch was 11-23 mmHg, whereas oxygen tension of the SVC perfusion blood was 210-398 mmHg. In only one patient, transient involuntary movement was seen after operation, but prolonged emergence from anesthesia was not seen. In conclusion, CRCP is considered as an useful method in the operation of the aortic arch.

Aorta, Thoracic↗
PubMed1992

[Surgical repair of distal aortic arch aneurysm using "elephant trunk" technique].

We present a surgical case of 61-year-old man with distal aortic arch aneurysm. Under selective cerebral perfusion in deep hypothermia, we approached to the aneurysm through median sternotomy. Dilated distal aortic arch and proximal descending aorta with mural thrombus in the aneurysmal lumen were found. The aortic occlusion balloon catheter was inserted into the descending aorta. A Cooley woven Dacron graft (26 mm in diameter) was anastomosed at 5 cm above its distal end loosely to the descending aorta with five interrupted mattress sutures, and the distal portion of the graft was pushed down into the distal aorta ("elephant trunk" technique). Postoperative course was uneventful and the dead space around the graft in aneurysm was filled with thrombus. Six months later, however, emergent operation was performed because of compression of the bronchus and the esophagus by enlargement of the aneurysm due to leakage. The second operation was approached through 5th left intercostal thoracotomy and median sternotomy. The aneurysm was opened, and the thrombus was amounted to 500 g. The distal end of the graft was anastomosed end-to-end to the mid-portion of the descending thoracic aorta. Postoperative course was uneventful and the patient was discharged. It is concluded that Elephant trunk technique is effective and the postoperative control of hypertension is very important.

Aorta, Thoracic↗
PubMed1991

Renotropic functions of hepatocyte growth factor in renal regeneration after unilateral nephrectomy.

Hepatocyte growth factor (HGF), a most potent growth factor for mature hepatocytes may act as a trigger for liver regeneration. We reported that HGF strongly stimulates DNA synthesis of rabbit renal tubular cells in secondary culture (Igawa, T., Kanda, S., Kanetake, H., Saitoh, Y., Ichihara, A., Tomita, Y., and Nakamura, T. (1991) Biochem. Biophys. Res. Commun. 174, 831-838). To investigate whether or not HGF is involved in renal regeneration, we examined changes in HGF mRNA, HGF activity, and HGF receptor in the rat kidney following unilateral nephrectomy or treatment with carbon tetrachloride (CCl4). In the intact kidney, the HGF mRNA increased markedly reaching a maximum 6 h after unilateral nephrectomy, followed by an increase of HGF activity at 12 h after the surgery. The marked increase in HGF mRNA and HGF activity was also found in the kidney of rats treated with CCl4. Results of in situ hybridization suggested that cells producing HGF in the kidney are endothelial cells. The number of HGF receptors on renal plasma membranes decreased to 30% of the normal value 12 h after unilateral nephrectomy, with no change in the Kd value. The HGF receptor was greatly diminished 24 h after the operation, and recovery to 60% of the normal level was evident 1 week after the operation. Because the decrease in HGF binding may result from internalization of the HGF receptor, the HGF may bind to its receptor in vivo and act as a mitogen for renal epithelial cells. HGF may function as a renotropic factor during renal regeneration after kidney injury.

Animals↗
PubMed1991

Involvement of retinoic acid and its receptor beta in differentiation of motoneurons in chick spinal cord.

Retinoic acid is known to play an important role during development of central nervous system. In order to clarify function of retinoic acid during the development, we investigated expression pattern of the chick retinoic acid receptor subtype beta gene by an in situ hybridization method. We found that expression of the beta gene is localized in neural tube at stages 16-20, then is turned to be restricted to developing motoneurons at stages 23-29. These results suggested that retinoic acid and its receptor beta are involved in differentiation of the motoneurons in spinal cord.

Animals↗
PubMed1991

Isoforms of retinoic acid receptor beta expressed in the chicken embryo.

The cDNA sequences of isoforms of retinoic acid receptor beta from the chick have been determined. The sequence is different from that reported previously only in the 5' region, suggesting a product of alternative splicing and differential usage of promoters. One of them, the novel RAR-beta 4 isoform, is presumed to encode an amino-terminal truncated region A of retinoic acid receptor beta.

Amino Acid Sequence↗
PubMed1991

Involvement of the Chox-4 chicken homeobox genes in determination of anteroposterior axial polarity during limb development.

We have isolated and identified four chicken homeobox genes in the upstream region of the Chox-4 complex. The Chox-4g and -4f genes, at the 5' extremity of the complex, were expressed locally in the vicinity of the zone of polarizing activity (ZPA) at early stages of limb development, substantiating the involvement of the genes in anteroposterior axis determination. To confirm their function, we implanted a bead containing retinoic acid, or the ZPA itself, in the anterior margin of the limb bud, leading to formation of mirror-image duplicated digits, and observed the resultant change in gene expression. Expression of the Chox-4g and -4f genes was induced in the new digit-forming region. Those results suggest that positional information assigned by a ZPA morphogen is imprinted on cellular memory by expression of the Chox-4 genes to maintain positional signaling along the anteroposterior axis in the limb field.

Amino Acid Sequence↗
PubMed1991

Bacterial endotoxin-induced expression of metallothionein genes in rat brain, as revealed by in situ hybridization.

In order to clarify acute-phase response in brain, we investigated induction of metallothionein (MT) genes by administrating an endotoxin (lipopolysaccharide) in rat intraperitoneum. We performed in situ hybridization on the serial brain sections to identify the cells expressing the MT genes in acute-phase. After endotoxin administration, transcripts of MT genes were detected in the arachnoideal, ependymal cells and glial cells around the Purkinje cells of the cerebellum, while no significant induction of the MT genes by zinc ion was observed in brain. These results suggest that the acute-phase response occurs specifically in at least these 3 non-neuronal cells.

Acute-Phase Proteins↗
PubMed1991

Retinoic acid induces polarizing activity but is unlikely to be a morphogen in the chick limb bud.

Retinoic acid is a putative morphogen in limb formation in the chick and other vertebrates. In chick limb formation, it is thought that retinoic acid is released from the zone of polarizing activity (ZPA) and the concentration gradient of retinoic acid formed from the posterior to the anterior provides positional cues for digit formation. Implantation of a bead containing retinoic acid at the anterior margin of the limb bud induces a mirror-image symmetrical duplication of the digit pattern similar to that observed when the ZPA is grafted into the anterior margin of the host limb bud. Also, the level of endogenous retinoic acid (25 nM on average) is higher in the posterior one third of the limb bud. We found that when the bead containing either retinoic acid or an analogue but not the ZPA, was implanted in the anterior margin of the chick limb bud, expression of the retinoic acid receptor type-beta gene was induced around the bead within 4 h. These results indicate that exogenous retinoic acid is not identical with the ZPA morphogen. As the anterior tissue exposed to retinoic acid has polarizing activity, we conclude that the primary function of exogenous retinoic acid is to induce polarizing activity in the limb bud.

Amino Acid Sequence↗
PubMed1991

Diurnal regulation of per repeat mRNA in the suprachiasmatic nucleus in rat brain.

'Per repeat is a rodent genomic DNA fragment which is homologous to the Gly-Thr repetitive amino acid sequence of the Drosophila clock gene period'. This study examined the temporal and spatial expression of the per repeat mRNA in rat brain. Northern blot analysis showed that the level of per repeat mRNA species fluctuates under light-dark cycle conditions in rat brain. Furthermore, the fluctuation of per repeat mRNA was clearly observed in the suprachiasmatic nucleus, but not so in other regions including the hippocampus as shown by in situ hybridization. The above results suggest that the Gly-Thr repetitive sequence also plays an important role in the circadian rhythm of mammals.

Animals↗
PubMed1991

Molecular cloning and sequence analysis of antigen gene tdpA of Treponema denticola.

We isolated and characterized an immunogenic protein of an oral spirochete, Treponema denticola Johnson. A genomic DNA library constructed with bacteriophage lambda EMBL3 as a vector was immunologically screened with a rabbit antiserum against the whole cells. Using Western immunoblot analysis, we found a particular clone encoding an antigen with a molecular weight of 53,000; we designated the antigen as T. denticola protein A (TdpA). Complete sequence determination revealed an open reading frame of 1,419 bp and a signal peptide sequence that was homologous to that of bacterial lipoprotein. Southern hybridization analysis revealed that the tdpA gene is highly conserved in six tested strains of T. denticola species. Furthermore, we found that sera from some periodontitis patients contained antibody against the TdpA protein, although the reactivities of the antibodies varied among individuals.

Amino Acid Sequence↗
PubMed1991

[A case of "postoperative erythroderma" following coronary artery bypass grafting operation].

So-called "Postoperative Erythroderma" was experienced in a 68 year-old man who received CABG for unstable angina. After a seemingly uneventful recovery, he revealed high grade fever on 13th post operative day (POD), rashes over the whole body on 15th POD and pancytopenia on 20th POD. He died of sepsis, multiple organ failure and DIC on 21st POD. Blood transfusion (concentrated red cell: 3 units) was done on operation. In this case, the rate of premature and atypical lymphocytes increased, and the ratio of OKT4 (helper)/OKT8 (suppressor) decreased. These findings of the examination suggested that there was a possibility of cell-mediated immunological depression. We considered this to be acute GVHD after blood transfusion.

Aged↗