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Biomedical subjects

Y Kikuchi

Publications and source records attributed to Y Kikuchi.

At least 289 records · Page 16Linked to original sources
PubMed1997

[Simultaneous surgical treatment for distal aortic arch aneurysm associated with innominate artery aneurysm and coronary artery disease].

The patient was 69-year-old male who admitted to our hospital in November 1995 with the complaint of abnormal shadow on chest C-ray. CT scan and aortogram revealed aneurysms of the distal aortic arch and innominate artery. Seventy-five percent stenosis of the right coronary artery was also found in coronary angiogram. The total arch replacement and reconstruction of the innominate artery and CABG to right coronary artery were performed with the aid of cold blood cardioplegia and selective cerebral perfusion and open distal anastomosis. Ascending aorta was used for arterial cannulation to avoid the thromboembolism due to retrograde perfusion from the femoral artery. Satisfactory postoperative course was obtained except transient left hemiplegia and post operative three-dimensional CT scan demonstrated the successful reconstruction. The patient was doing well 8 months postoperatively.

Aged↗
PubMed1997

[Blood rheological study in rats with fatty liver--with special reference to effects of ethyl icosapentate].

A blood rheological study was conducted using Kikuchi's micro-channel method in rats with fatty liver. Effects of eicosapentaenoic acid (EPA) on blood rheology were also evaluated. Male SD rats given normal feed served as the control. One group was given choline-deficient feed for 4 weeks (EPA (-) group), while another group was daily given EPA (1000 mg/kg) for 4 weeks together with choline-deficient feed (EPA (+) group). The micro-channel passage time was determined using 100 microliters of whole blood. The passage time significantly increased in the EPA (-) group compared to the control (p < 0.01). It significantly decreased in the EPA (+) group compared to the EPA (-) group (p < 0.01). Findings obtained in the present study suggested that blood rheological factors are related to the development of fatty liver and that EPA inhibits fatty changes of the liver by improving these rheological factors.

Animals↗
PubMed1997

[Concomitant composite graft replacement of the aortic root and the aortic arch for type A aortic dissection].

Successful surgical treatment of type A aortic dissection with annuloaortic ectasia (AAE) and severely destroyed aortic root was reported. Between April 1991 and April 1996, 26 patients with type A aortic dissection underwent the surgical treatment in our institute. Among those cases, 4 cases (15%) needed the total aortic root replacement with composite graft. Two cases had Marfan syndrome and AAE and aortic regurgitation. Other two cases had severely destroyed aortic root because of the extension and advancement of the dissection to the aortic root. One was the case of disrupted right coronary ostia. And another was the case of frank rupture and massive bleeding from the aortic root during the operation. Cases of AAE were treated successfully by the routine composite graft that was made before the operation. However, the reconstruction of the aortic root for the cases who had destroyed aortic root with normal relation and size of the aortic root was cumbersome because of non displaced coronary artery ostia and the relatively narrow aortic root. For these cases, composite graft was fixed just below the aortic valve annulus by the sutures enforced with Teflon felt strip from the outside of the aorta and it made the reimplantation of the coronary ostia easier. As for the technique of the reimplantation of the coronary ostia, Carrel patch technique was used because good coaptation and fixation of the suture line around the coronary ostia could be obtained with this technique which prevent the complication such as the pseudoaneurysm or the periostial aneurysm formation around the coronary artery in the long term period. Concomitant procedures were aortic arch replacement in all cases, total arch replacement with four vessels graft in 3 cases and hemiarch replacement in 1 case. Each operations were performed with the aid of selective cerebral perfusion and open distal anastomosis.

Aged↗
PubMed1997

[Clinical evaluation of heparin concentration and activated clotting time monitoring (HEPCON HMS) system].

The HEPCON HMS system provides both activated clotting time (ACT) and accurate whole blood heparin concentration measurements. We evaluated the impact of heparin and protamine administration using this system on the incidence and treatment of bleeding after performing a cardiopulmonary bypass. Patients were randomly divided into two groups. Heparin and protamine administration during extracorporeal circulation was determined by classical ACT management in Group A (n = 15) and by HEPCON HMS system in Group H (n = 19). There were no statistical differences in the coagulation factor, the postoperative chest tube drainage or the blood products used between the two groups. Patients in Group H received a higher dosage of heparin and a lower dosage of protamine compared with Group A. By facilitating the maintenance of a therapeutic heparin concentration and by determining an appropriate protamine dosage, the HEPCON HMS system may be useful in managing extracorporeal circulation.

Blood Coagulation Tests↗
PubMed1997

[Evaluation of neuro-Behçet disease with 99mTc-HMPAO brain SPECT: comparison with MR imaging].

The purpose of this study was to evaluate the brain perfusion of neuro-Behçet disease using 99mTc-HMPAO. In total, nine patients (7 men and 2 women) were evaluated. Seven were in the chronic phase, one was acute and the other was subacute. The results of perfusion study were compared with the MRI findings. The findings of chronic-phase neuro-Behçet disease were as follows: 99mTc-HMPAO showed hypoperfusion of the cerebellum in 3, brain stem in 5, and cerebral cortex in 4 patients. Moreover, asymmetry of the basal ganglia and thalamus was seen in 4 cases with 99mTc-HMPAO. MRI showed atrophy of the cerebellum in 4, brain stem in 5 and cerebral cortex in 2 patients. One acute patient showed a perfusion defect with 99mTc-HMPAO that was consistent with the vasculitis shown with MRI. In the remaining subacute patient, perfusion defect was demonstrated with 99mTc-HMPAO, consistent with the infarction shown with MRI. It is concluded that brain perfusion scintigraphy is useful to evaluate the brain blood flow of neuro-Behçet disease.

Adult↗
PubMed1997

[A case of paraplegia after graft replacement of the ascending aorta and the total aortic arch for the DeBakey type I acute aortic dissection].

A rare case of paraplegia after an emergency operation for DeBakey type I acute aortic dissection was reported. The patient was a 52-year-old female who complained of severe chest and back pain. She underwent graft replacement of the ascending aorta and the total aortic arch. No neurological symptoms were observed before the operation. The cause of the paraplegia was assumed to be a thrombotic occlusion of costal arteries which originated from the false lumen.

Aortic Dissection↗
PubMed1997

[Minimally invasive coronary artery bypass grafting and percutaneous coronary angioplasty in the patient with left main disease and chronic renal failure].

This paper describes the utility of the minimally invasive CAB procedure as an adjuvent therapy to allow angioplasty for left main stenosis. A 73-year-old male who had chronic renal failure and left main coronary disease underwent a combined therapy with minimally invasive CABG and PTCA. The operation was reformed with a 9 cm incision. The fifth costal cartilage was removed. Internal thoracic artery (ITA) was dissected from the left side of the chest wall and anastomosed to the midportion of the left anterior descending coronary artery (LAD) with 7-0 with 7-0 Prolene. He was extubaded a few hours after the operation and resumed his dialysis schedule. On the fifth postoperative day he was electively returned to the catheterization laboratory, where he underwent successful angioplasty of the LMT to Lcx after patency of the LITA-LAD graft had been verified. He was discharged from our hospital ten days postoperatively.

Aged↗
PubMed1997

Design and in vitro activity of ribozymes against mRNA of a rat membrane inhibitor of complement.

Mammalian cells are usually protected from the complement-mediated injury by a number of complement regulatory proteins. A rat protein designated as 512 antigen is thought to be such a complement regulatory protein. A cDNA of 512 antigen has been cloned and analyzed. To investigate the function of 512 antigen, we plan to construct a ribozyme system against 512 antigen expression. We have designed two hammerhead ribozymes targeted to the 512 antigen mRNA and tested the ribozyme activities in vitro. Both hammerhead ribozymes efficiently cleaved the 512 antigen mRNA in vitro. We have also designed a hairpin ribozyme against this mRNA. The activity of the hairpin ribozyme will also be discussed.

Animals↗
PubMed1997

RNA aptamers to a protease, subtilisin.

RNA ligands (RNA aptamers) to a protease subtilisin were selected from pools of random RNA using SELEX (Systematic evolution of ligands by exponential enrichment). We selected RNA aptamers using a subtilisin-immobilized Sepharose column. After several rounds of selection, we obtained RNA aptamers that specifically inhibit the subtilisin activity. Characterization of the RNA aptamers will be reported.

Binding Sites↗
PubMed1996

Characterization of a new calcium-binding protein abundant in amniotic fluid, CAAF2, which is produced by fetal epidermal keratinocytes during embryogenesis.

By using a 45Ca2+ overlay technique, we found two calcium-binding proteins (CaBPs) abundant in bovine amniotic fluid, and named them CAAF1 (calcium-binding protein in amniotic fluid-1) and CAAF2. CAAF1 was identified as a novel S100 protein produced by fetal epidermal keratinocytes, squamous epithelial cells and polymorphonuclear leukocytes. Here, we report the primary structure and the tissue distribution of bovine CAAF2. CAAF2 is a newly isolated protein with the two EF hand motifs peculiar to S100 proteins, and 29.7% homology to CAAF1. CAAF2 is 63.4% homologous to human psoriasin, a S100 protein up-regulated in psoriatic epidermis. Northern blot analysis demonstrates that CAAF2 is unique in that it is exclusively expressed in the epidermis. Our results suggest that the majority of CaBPs in amniotic fluid consist of two distinct S100 proteins, CAAF1 and CAAF2, which are produced by fetal epidermal keratinocytes.

Amino Acid Sequence↗
PubMed1996

The primary gustatory area in human cerebral cortex studied by magnetoencephalography.

Magnetic fields (MFs) from gustatory stimulation with 1 M NaCl and 3 mM saccharin were recorded from the human brain by using a whole-cortex SQUID system. The averaged onset latency of MFs was 93 ms for NaCl and 172 ms for saccharin and no response was obtained for water. A high correlation coefficient was noted between the difference of onset MFs latencies in two tastants and that of behavioral reaction times, and responses to saccharin were delayed or abolished after treatment of a subject's tongue with a sweet-suppressing agent. This finding indicates that the MFs obtained were caused by gustatory stimulation. By plotting the estimated current dipole on the magnetic resonance image, we could locate the primary gustatory area at the transition area between the operculum and insula, as reported in macaque monkeys.

Adult↗
PubMed1996

Mermaid: a family of short interspersed repetitive elements widespread in vertebrates.

We have discovered a family of short interspersed repetitive elements (SINEs) that are present in the genomes of fish, amphibian and primates. The family of the SINEs, designated mermaid, is distinctive in each species except for a conserved region of approximately 80 bp. Some members of the mermaid family were found in transposon-like repetitive elements, including Tcl-like elements which were also distributed in the genomes of fish and amphibian. This raises the possibility of horizontal transfer of the mermaid family between vertebrates via transposons.

Amphibians↗
PubMed1996

Mermaid, a family of short interspersed repetitive elements, is useful for zebrafish genome mapping.

A family of short interspersed repetitive elements (SINEs), designated mermaid, is present in the genomes of fish, amphibian and primates, but absent in the mouse genome. We have demonstrated that the sequences of the mermaid family are highly polymorphic in the zebrafish genome as in the human genome. We have also shown that the mermaid sequence can be used to recover zebrafish specific DNA from zebrafish-mouse cell hybrids by using mermaid-specific oligonucleotides as PCR primers. Thus, the mermaid family serves as a valuable genetic tool for the zebrafish genome mapping.

Animals↗
PubMed1996

Clinical application of the computer picture archiving and communicating system to stereotactic radiosurgery.

Stereotactic radiosurgery, a rapidly evolving technology, provides precise high-dose irradiation to brain lesions and tumors. A new method using digital subtraction angiographic images of a personal computer-image display terminal interfaced to our picture archiving and communication system (PACS) performs measurements and calculations of the coordinates of the location of the center of the lesion to be treated. The time required to calculate the coordinates was performed by three methods: hand calculation, digitizer method, and PACS method. These three coordinates were compared in 10 cases. The hand calculation method required approximately 50 minutes, the digitizer method required approximately 10 minutes, and the PACS method approximately 3 minutes. The difference is statistically significant (P < .001). The three methods were equally accurate. This type of PACS application using inexpensive personal computers interfaced more directly to a PACS is an emerging trend that facilitates wider access to images and to manipulating them for specialized applications.

Humans↗
PubMed1996

Effects of granulocyte-colony-stimulating factor and interleukin-2 on ascites formation and the survival time of nude mice bearing human ovarian cancer cells.

The aim of this study was to elucidate the effect of intraperitoneal (i.p.) instillations of granulocyte-colony-stimulating factor (G-CSF) and/or interleukin-2 (IL-2) on ascites formation and the survival time of nude mice with malignant ascites, produced by i.p. inoculation of human ovarian cancer cells. When the nude mice were treated with medium alone, ascites was observed in all mice 28 days after tumor inoculation. When the mice were treated with cis-diamminedichloroplatinum(II) (cisplatin) alone, G-CSF alone or IL-2 alone, it took 35 days for the ascites to form in all mice. When cisplatin was combined with G-CSF or IL-2, one of ten mice did not form ascites during the observation period. Surprisingly, when G-CSF and IL-2 were simultaneously administered, ascites formation was not observed in any mice. Although i.p. treatment with cisplatin alone significantly prolonged the survival time, compared to medium alone, the lytic activity of spleen cells against HRA cells was significantly suppressed. When G-CSF or IL-2 was combined with cisplatin, the suppression by cisplatin was eliminated and subsequently resulted in a prolongation of the survival time. When G-CSF was combined with IL-2, both the peritoneal and splenic macrophages/ monocytes were stimulated and the splenic lytic activity was about double that following treatment with G-CSF alone on IL-2 alone, suggesting that complete inhibition of ascites formation results not only from a significant increase of the peritoneal macrophages but also from enhancement of the lytic activity. Two mice, died from dissemination of tumor in the abdominal cavity, but eight mice survived without tumor for more than 90 days. As confirmed by monitoring body weight and hematocrit, G-CSF and IL-2 seemed to have no adverse effect. From these results, we conclude that a combination therapy with G-CSF and IL-2 might be of clinical use for inhibiting large amounts of ascites, which may inhibit therapeutic effects for ovarian cancer patients.

Adjuvants, Immunologic↗
PubMed1996

Effectiveness of a thermal shape-memory patent ductus arteriosus occlusion coil.

A new shape-memory coil for transcatheter closure of the PDA was developed and evaluated in a dog PDA model. The coil is sensitive to temperature (composed of thermal shape-memory nickel-titanium). The coil was delivered to and implanted in the PDA model with a 5F catheter through the femoral artery. The PDA model was made in 14 dogs by infrarenal aorta banding (diameter 2.0 +/- 0.6 mm; length 2.9 +/- 0.1 mm). Coils were implanted in 10 dogs, whereas the other 4 dogs served as controls. Complete occlusion of the PDA model was confirmed by angiography 24 hours after the coil implantation in 7 of 10 dogs, whereas small residual flow was noted even 2 weeks after the coil implantation in the other 3 dogs. The PDA model internal diameter in the dogs with complete occlusion (1.8 +/- 0.2 mm) was significantly smaller than the diameter in dogs with residual flow (2.9 +/- 0.4 mm, P < 0.05). In the 4 control dogs, the PDA model remained patent 2 weeks after the banding. We conclude that the transcatheter occlusion with the shape-memory coil was effective in the small-diameter PDA model.

Animals↗
PubMed1996

Critical proline residues of the cytoplasmic domain of the IL-5 receptor alpha chain and its function in IL-5-mediated activation of JAK kinase and STAT5.

The high-affinity receptor (R) for IL-5 consists of a unique alpha chain (IL-5R alpha) and a beta chain (beta c) that is shared with the receptors for IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF). We defined two regions of IL-5R alpha for the IL-5-induced proliferative response, the expression of nuclear proto-oncogenes, and the tyrosine phosphorylation of cellular proteins including beta c, SH2/SH3-containing proteins and JAK2 kinase. In the studies described here, we demonstrate that IL-5, IL-3 or GM-CSF stimulation induces the tyrosine phosphorylation of JAK2, and to a lesser extent JAK1, and of STAT5. Mutational analysis revealed that one of the proline residues, particularly Pro352 and Pro355, in the membrane-proximal proline-rich sequence (Pro352-Pro353-X-Pro355) of the cytoplasmic domain of IL-5R alpha is required for cell proliferation, and for both JAK1 and JAK2 activation. In addition, transfectants expressing chimeric receptors which consist of the extracellular domain of IL-5R alpha and the cytoplasmic domain of beta c responded to IL-5 for proliferation and tyrosine phosphorylation of JAK1. Intriguingly, electrophoretic mobility shift assay analysis revealed that STAT5 was activated in cells showing either JAK1 or JAK2 tyrosine phosphorylation. These results indicate that activation of JAK1, JAK2 and STAT5 is critical to coupling IL-5-induced tyrosine phosphorylation and ultimately mitogenesis, and that Pro352 and Pro355 in the proline-rich sequence appear to play more essential roles in cell growth and in both JAK1/STAT5 and JAK2/STAT5 activation than Pro353 does.

Animals↗