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Biomedical subjects

S Taniguchi

Publications and source records attributed to S Taniguchi.

At least 451 records · Page 25Linked to original sources
PubMed1992

[Intra-atrial implantation of mitral valve prosthesis in 2 patients with active infective endocarditis complicated by mitral annular destruction].

This is a report of two patients with extensive destruction of the mitral annulus due to active infective endocarditis. Patient 1 was a 66-year-old female and the patient 2 was a 59-year-old male. In both patients medical therapy had failed to control endocarditis and emergency mitral valve replacements were carried out. At the operation special surgical techniques were necessitated, since insertion of artificial valves in the annulus was impossible because of the lack of the annular tissue due to destruction and excision. On the posterior commissure side, mitral valve prosthesis were sutured to the left atrial wall just above the anatomical mitral ring. Furthermore, in patient 2, a bovine pericardium collar attached to the prosthetic valve was sutured to the left atrial wall to secure fixation of the prosthetic valve. The postoperative courses were uneventful in both patients. This technique seems to be useful in patients with mitral annular destruction.

Aged↗
PubMed1992

[Therapeutic evaluation of imipenem/cilastatin sodium for bacterial infections in patients with hematological diseases].

1. To evaluate the efficacy and tolerance of imipenem/cilastatin sodium (IPM/CS) in severe infections associated with hematopoietic disorders, IPM/CS was administered to a total of 105 patients. 2. Out of 96 patients evaluable for efficacy, clinical responses were excellent in 23 patients, good in 30, fair in 15, poor in 19 and unknown in 9, and the overall response rate was 60.9%. 3. The most common underlying hematopoietic disease was acute non-lymphocytic leukemia and the most common infections were sepsis and suspected sepsis. 4. Daily dose, severity of infection and neutrophil count had effects on the clinical response. 5. The overall eradication rate of bacteria was 83.7%. 6. Side effects were observed in 10 patients (9.5%) and abnormal laboratory test results in 12 (11.4%). From the above findings, we have concluded that IPM/CS is very useful for the treatment of severe infections in compromised patients with hematopoietic diseases.

Adult↗
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

Characterization of partially purified prostaglandin E2 receptor from the canine renal medulla: evidence for physical association of the receptor protein with the inhibitory guanine nucleotide-binding protein.

Prostaglandin (PG) E2 binding protein, a putative PGE2 receptor, was purified 26-fold with 0.4% recovery from canine renal outer medullary membranes solubilized with 12% digitonin with the sequential use of a Superose 12, Wheat Germ Agglutinin (WGA) Affigel 10, DEAE-5PW and Ampholine column chromatographies. The final preparation retained the binding activity specific for PGE2, but lost most of the sensitivity to guanosine-5'-(gamma-thio)triphosphate (GTP gamma S). An antibody against alpha subunit of the inhibitory guanine nucleotide-binding protein (alpha Gi)1 and alpha Gi2 or that against common sequences of alpha subunit of guanine nucleotide-binding proteins (alpha G(common)) reacted at 41 kDa protein in the sample of each step of purification, but failed to do so in the final preparation. An antibody against alpha Gi3 or alpha Go had no effect. In fact, peaks of the binding activity and immunoreactivity for alpha Gi1,2 were chromatographically separated by isoelectric focusing. Moreover, antibodies against alpha G(common) or alpha Gi1,2, but not that against alpha Gi3 and alpha Go, precipitated PGE2 binding activity in the active fractions of WGA-Affigel 10 column chromatography. These results suggest that the PGE2 receptor is an acidic glycoprotein and that Gi1 or Gi2 is physically associated with the PGE2 receptor and dissociates from the receptor protein during purification procedures.

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

Therapeutic efficacy of two-route chemotherapy using cis-diamminedichloroplatinum(II) and its antidote, sodium thiosulfate, combined with the angiotensin-II-induced hypertension method in a rat uterine tumor.

To enhance the therapeutic effect of conventional TRC using intra-arterial (i.a.) DDP plus simultaneous i.v. STS, we combined the AT-II-induced hypertension method with TRC and evaluated its efficacy for a rat uterine tumor, using the simulation of intra-arterial chemotherapy for human uterine tumors. During interruption of arterial blood flow by vascular manipulations, DDP plus AT-II were injected for 10 min through the abdominal aorta in the direction of the uterus. Then STS was administered i.v. for a further 5 min and all the arterial restrictions were released. This modified TRC using AT-II showed a much higher anti-tumor effect than that seen in conventional TRC without AT-II and was free from DDP-induced renal damage. On the other hand, severe nephrotoxicity was unavoidable in the rats given the delayed i.v. administration of STS to i.a. DDP alone. The feasibility of post-administration of STS without obvious nephrotoxicity in modified TRC was explained by transient inhibition of DDP delivery to the kidney during the AT-II-induced hypertension. The loss of body weight and the decrease in the number of leukocytes after this therapy were tolerable. Modified TRC showed a higher anti-tumor effect and a lower nephrotoxicity compared with other treatments, as follows: DDP i.a. with or without AT-II; i.v. infusion of DDP alone. Such a superior anti-tumor effect of modified TRC consists of the following 2 factors: (i) the post-administration of STS leading to the delayed neutralization of DDP at the tumor site; (ii) the selective enhancement of DDP delivery to the tumor tissue during AT-II-induced hypertension.

Angiotensin II↗
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

Hierarchical regulation of interleukin production: induction of interleukin 6 (IL-6) production from bone marrow cells and marrow stromal cells by interleukin 3 (IL-3).

IL-3 stimulated the production of IL-6 from a bone marrow-adherent cell population, macrophages and from hemopoietic supportive stromal cell lines. It also induced IL-6 production from a stem cell-enriched population of bone marrow cells which did not produce IL-6 without stimulation. In contrast, stimulation with IL-6 of all the cell populations studied in the present experiments did not induce IL-3 production. These results indicate a hierarchical network in the regulation of interleukin production, and existence of a positive feedback mechanism; IL-3 induces IL-6 production which in turn stimulates stem cells into cycle and induces stem cells to respond to IL-3.

Animals↗
PubMed1991

Prevention of genetic resistance to bone marrow allografts by reticuloendothelial system blockade.

Agents which are toxic to macrophages such as silica and caragheenan suppress genetic resistance to bone marrow allografts. However, these agents may also be toxic to other tissues and cannot be used for the establishment of long-term bone marrow chimerism. In this study, we used chemically insert carbon particles to blockade phagocytic cells, and succeeded in carrying out bone marrow allografts. Long-term survival of the recipient mice after bone marrow transplantation (BMT) was achieved without apparent evidence of graft-versus-host reaction (GVHR), although T-cells were not depleted in donor marrow cells. The hemopoietic system of the recipient mice was replaced by that of donor origin. These results indicate that phagocytic cells play an essential role, probably as effector cells in genetic resistance to bone marrow allograft.

Animals↗
PubMed1991

Effect of tretinoin on collagen gel contraction induced by mouse 3T3 fibroblasts.

Balb/3T3 fibroblasts were cultured in type I collagen gel and the effects of tretinoin (all-trans-retinoic acid) were examined on cell growth and the gel contraction produced by cells. Cell proliferation was suppressed and the degree of gel contraction was enhanced by the addition of 10(-7) and 10(-6) M tretinoin. Growth and gel contractility of transformed cells derived from the Balb/3T3 cells were not influenced by this agent. Addition of 12-O-tetradecanoylphorbol ester, which is known to antagonize tretinoin in several biological processes, enhanced gel contraction synergistically with tretinoin. These results suggest that tretinoin influences cell-to-collagen interactions.

Animals↗
PubMed1991

The objective measurement of pain using a motor-performance task.

An objective method for measuring endogenous pain in the wrist which originates in cervicobrachial disorders was improved. The method employed the plate-pushing task, which was reported previously (Taniguchi and Satow 1988a, b). The first improvement was achieved by introducing a load to be placed on the wrist while subjects were pushing the plate. In this way, it became easier to induce pain caused by disorders in the wrist. Another improvement was a new procedure by which a subject was told to change her pressure against a balance as instructed. This made it possible to identify the degree of pressure exerted which produce pain. Effects of dominance of hands, and of ordering the trials so as to begin with the dominant hand and switch to non-dominant, or vice versa in the tests were also examined, but were found to be not significant. Finally, the new method proved to be highly useful as an objective method for measuring pain of this sort because the method could produce very similar conditions to those associated with ordinary pain causing motion.

Adolescent↗
PubMed1991

Effects of butylated hydroxyanisole on ornithine decarboxylase activity and its gene expression induced by phorbol ester tumor promoter.

Butylated hydroxyanisole (BHA) is a phenolic antioxidant that has been found to suppress the activity of skin tumor promoters. In this study, we investigated the effect of BHA on the activity of ornithine decarboxylase (ODC, an indicator of tumor promotion) and its gene expression induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in mouse skin. TPA-induced ODC activity was markedly inhibited by the topical application of 55 mumol of BHA (the inhibition rate at 6 h was about 80%). In Northern and dot-blot analysis, the TPA-induced increase in ODC mRNA was shown to be markedly reduced by the same dose of BHA (the inhibition rate at 4 h was about 60%). These results suggest the involvement of a decrease in ODC gene expression in the mechanism of the inhibition of ODC activity by BHA.

Animals↗