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S Taniguchi

Publications and source records attributed to S Taniguchi.

At least 73 records · Page 4Linked to original sources
PubMed2002

[Modification of repeat lateral minimally invasive direct coronary artery bypass; left axillary artery to circumflex artery bypass].

A 69-year-old man underwent triple coronary artery bypass graftings [LITA (left internal thoracic artery)-LAD (left anterior descending artery), SVG (saphenous vein graft)-PD (postac-descending artery), SVG-PL (postero-lateral artery)] 11 years previously. Recently, angina pectoris occurred due to the graft disease of SVG-PL. A repeat modified lateral minimally invasive direct coronary artery bypass (MIDCAB) [left axillary artery-PL using SVG] was performed. The left axillary artery was chosen as inflow vessel for coronary artery bypass graft because of the difficult descending aorta and patent LITA-LAD. Postoperative course was uneventful. The left axillary artery to circumflex artery bypass could be one of the option of the lateral MIDCAB.

Aged↗
PubMed2001

Structural fragility of blood vessels and peritoneum in calponin h1-deficient mice, resulting in an increase in hematogenous metastasis and peritoneal dissemination of malignant tumor cells.

We have observed weak expression of calponin h1, which stabilizes the actin filament system, in blood vessels within human malignant tumors. This observation suggested that because of a deficiency in stabilization by calponin h1, the structure of blood vessels in malignant tumors is fragile compared with blood vessels in normal tissues. We therefore generated calponin h1-deficient (CN(-/-)) mice to examine the effect of calponin h1 on the integrity of the barrier system in blood vessels against cancer metastasis. The CN(-/-) mice exhibited morphological fragility of the tissues, including the uterus and blood vessels. In particular, we frequently observed bleeding into the surrounding tissue from blood vessels of the ocular fundus in CN(-/-) mice. In addition, mesothelial cells, which usually express calponin h1 in normal (CN(+/+)) mice, were retracted in the CN(-/-) mice. When fluorescein was injected i.v. into mice, the CN(-/-) mice exhibited a greater and more rapid leakage of fluorescein from the blood vessels of the ocular fundus compared with the CN(+/+) mice. In the CN(-/-) mice receiving i.v. inoculations of B16 melanoma cells, significantly more metastatic nodules were formed in the lung than in the CN(+/+) mice. When B16 melanoma cells were injected i.p., the severity of peritonitis carcinomatosa was greater in CN(-/-) than in CN(+/+) mice. These results indicate that calponin h1 plays an important role in the regulation of the integrity of the blood vessels and peritoneum, which in turn is an important factor influencing the frequency of cancer metastasis. The CN(-/-) mice, which exhibit fragile blood vessels and peritoneum, could serve as sensitive and useful host models to investigate cancer metastasis.

Actins↗
PubMed2001

Determination of polychlorinated biphenyls in Antarctic macroalgae Desmarestia sp.

Selected polychlorinated biphenyl (PCB) congeners were measured in Desmarestia sp., an abundant algae in the Antarctica Peninsula and South Shetlands. Samples were collected from various points of Admiralty Bay, King George Island, Antarctic Peninsula, during the 1993-1994 austral summer. Total PCB concentrations ranged from 0.46 to 3.86 ng g(-1) (dry weight). Predominant PCB congeners were 52, 101, 110, 138 and 153. The low levels of PCBs found on all samples and the predominance of low molecular weight congeners indicate that there are no significant local PCBs sources in the area of study.

Antarctic Regions↗
PubMed2001

Puromycin aminonucleoside induces apoptosis and increases HNE in cultured glomerular epithelial cells(1).

Puromycin aminonucleoside induces apoptosis and increases 4-hydroxy-2-nonenal (HNE) in cultured glomerular epithelial cells. We have previously reported the detachment of cultured glomerular epithelial cells (GECs) from their substrata by puromycin aminonucleoside (PAN) treatment. In this study we explored whether or not apoptosis was involved in the mechanisms of the detachment. DNA fragmentation on gel electrophoresis was clearly shown by 10(-3) M PAN treatment of GECs. Nuclear staining by Hoechst 33342 indicated the greatest number of apoptotic cells at 10(-3) M PAN for 48 h treatment. Similarly, TUNEL methods revealed maximal apoptotic cells at 10(-3) M PAN for 48 h treatment. Caspase-3 (like) protease activity increased at 10(-3) M PAN, and decreased at 2 x 10(-3) M PAN for 48 h treatment as well as at 10(-3) M PAN for 60 h treatment. Pretreatment with 2'-deoxycoformycin (DCF), inhibitor of adenosine deaminase, abolished these effects of PAN on cultured GECs. PAN treatment increased HNE, a lipid peroxide adduct, modified protein in cultured GECs, which was also prevented by pretreatment by DCF. These results for the first time indicate that the PAN-induced detachment of GECs from culture substrata is mediated at least in part through apoptosis via oxidative stresses by adenosine deaminase activity.

Adenosine Deaminase Inhibitors↗
PubMed2001

Stable operation of a 300-m laser interferometer with sufficient sensitivity to detect gravitational-wave events within our galaxy.

TAMA300, an interferometric gravitational-wave detector with 300-m baseline length, has been developed and operated with sufficient sensitivity to detect gravitational-wave events within our galaxy and sufficient stability for observations; the interferometer was operated for over 10 hours stably and continuously. With a strain-equivalent noise level of h approximately 5x10(-21)/sqrt[Hz], a signal-to-noise ratio of 30 is expected for gravitational waves generated by a coalescence of 1.4M-1.4M binary neutron stars at 10 kpc distance. We evaluated the stability of the detector sensitivity with a 2-week data-taking run, collecting 160 hours of data to be analyzed in the search for gravitational waves.

Astronomy↗
PubMed2001

A homologue of N-ethylmaleimide-sensitive factor in the malaria parasite Plasmodium falciparum is exported and localized in vesicular structures in the cytoplasm of infected erythrocytes in the brefeldin A-sensitive pathway.

N-Ethylmaleimide-sensitive factor (NSF) and its homologues play a central role in vesicular trafficking in eukaryotic cells. We have identified a NSF homologue in Plasmodium falciparum (PfNSF). The reported PfNSF gene sequence (GenBank accession number CAB10575) indicated that PfNSF comprises 783 amino acids with a calculated molecular weight of 89,133. The overall identities of its gene and amino acid sequences with those of rat NSF are 50.9 and 48.8%, respectively. Reverse transcription-polymerase chain reaction analysis and Northern blotting with total P. falciparum RNA indicated expression of the PfNSF gene. Polyclonal antibodies against a conserved region of NSF specifically recognized an 89-kDa polypeptide in the parasite cells. After homogenization of the parasite cells, approximately 90% of an 89-kDa polypeptide is associated with particulate fraction, suggesting membrane-bound nature of PfNSF. PfNSF was present within both the parasite cells and the vesicular structure outside of the parasite cells. The export of PfNSF outside of the parasite cells appears to occur at the early trophozoite stage and to terminate at the merozoite stage. The export of PfNSF is inhibited by brefeldin A, with 9 microM causing 50% inhibition. Immunoelectromicroscopy indicated that intracellular PfNSF was associated with organelles such as food vacuoles and that extracellular PfNSF was associated with vesicular structures in the erythrocyte cytoplasm. These results indicate that PfNSF expressed in the malaria parasite is exported to the extracellular space and then localized in intraerythrocytic vesicles in a brefeldin A-sensitive manner. It is suggested that a vesicular transport mechanism is involved in protein export targeted to erythrocyte membranes during intraerythrocytic development of the malaria parasite.

Amino Acid Sequence↗
PubMed2001

Pyrin N-terminal homology domain- and caspase recruitment domain-dependent oligomerization of ASC.

ASC was first identified as a caspase recruitment domain (CARD)-containing proapoptotic molecule that forms insoluble aggregates during apoptosis. Here, we report both the pyrin N-terminal homology domain (PYD) and CARD domains are involved in the aggregation of ASC. Preliminary experiments indicated that overexpression of ASC formed filament-like aggregates in COS-7 cells. Expression experiments using green fluorescent protein (GFP) constructs showed that not only the GFP-ASC-CARD but also the GFP-ASC-PYD formed filament-like aggregates in COS-7 cells. We confirmed these filament-like aggregates of both the ASC-PYD and the ASC-CARD due to homophilic interaction by immunoprecipitation method. We also demonstrated that the ASC-PYD associated with the ASC-CARD by heterophilic interaction. These observations suggest that the dimerization of the PYD as well as the CARD plays an important role in the oligomerization of ASC as an adaptor molecule.

Animals↗
PubMed2001

Calpain-mediated degradation of p35 to p25 in postmortem human and rat brains.

Tau in Alzheimer neurofibrillary tangles has been shown to be hyperphosphorylated and CDK5, GSK3, MAP kinase and SAP kinases are the candidate kinases for the phosphorylation of tau. Recently, it was reported that the conversion of p35, the activator of CDK5, to p25 was upregulated in Alzheimer's disease (AD) brains, and that p35 is cleaved to yield p25 by calpain. Here we show that p35 is rapidly cleaved to p25 in rat and human brains within a short postmortem delay and that the conversion of p35 to p25 is partially dependent on calpain activity. Immunoblot analysis of brains prepared from patients with AD or age-matched control individuals with a short postmortem delay revealed no specific increase in the levels of p25 in AD brains, whereas the levels of active form of calpain were increased in AD brains compared to the those in controls. These observations suggest that the conversion of p35 to p25 is a postmortem degradation event and may not be upregulated in AD brains.

Aged↗
PubMed2001

Murine ortholog of ASC, a CARD-containing protein, self-associates and exhibits restricted distribution in developing mouse embryos.

ASC (apoptosis-associated speck-like protein containing a CARD) was first identified as a cytosolic soluble protein that forms insoluble aggregates and enhances etoposide-induced apoptosis. We have cloned a murine ortholog of ASC (mASC) comprising 193 amino acids with a well-conserved pyrin N-terminal homology domain and caspase recruitment domain (CARD). mASC fused with green fluorescent protein appeared as a speck in transfected COS-7 cells and showed self-association. We analyzed mASC gene expression in developing embryos by in situ hybridization and found it to have a restricted distribution in mouse embryos. At E9.5, mASC was strongly expressed in the telencephalon, thalamic areas of the diencephalon, heart, and liver. Northern blotting analysis revealed that the mASC gene was expressed ubiquitously in multiple organs in adult mice. These findings indicate that mASC shows conservation of not only the primary structure of human ASC but also the ability to aggregate and has some similarity in its distribution to other CARD-containing molecules, including the apoptosis regulator Apaf-1.

Amino Acid Sequence↗
PubMed2001

Lung volume reduction surgery and nutritional status in patients with severe emphysema.

OBJECTIVE: We studied the short-term effect of lung volume reduction surgery on nutritional status including body composition and the relationship between preoperative nutritional status and postoperative morbidity. METHODS: Subjects were 28 patients with emphysema who underwent bilateral thoracoscopic lung volume reduction surgery (23 simultaneously, 5 staged). Functional tests, body weight, and body composition were measured before and 6 months after surgery. Fat-free mass and fat mass were assessed by bioelectrical impedance analysis. RESULTS: FEV1.0 improved 35.2% following surgery and maximal oxygen uptake 23.8%. Body weight and fat-free mass increased significantly after surgery, while fat mass was unchanged. Of the 23 undergoing simultaneous bilateral lung volume reduction surgery, 8 had major complications-3 required additional surgery to close air leaks, 3 required mechanical ventilation (> 72 hrs), and 2 developed postoperative infection. The preoperative percentage of ideal body weight and fat-free mass was significantly higher among patients without major complications. CONCLUSIONS: Bilateral lung volume reduction surgery increases fat-free mass and provides functional improvement for underweight patients with severe emphysema. We found fat-free mass and body weight to be good predictors of unacceptable postoperative complications following bilateral lung volume reduction surgery.

Aged↗
PubMed2001

Reoperative coronary artery bypass grafting using a minimally invasive direct coronary artery bypass procedure.

OBJECTIVE: Reoperative coronary artery bypass grafting with cardiopulmonary bypass tends to cause a higher mortality and morbidity than the primary operation. The purpose of this study was to discuss the effectiveness and safety of a minimally invasive coronary artery bypass procedure for patients who had previously undergone coronary artery bypass surgery. METHODS: We performed redo single coronary artery bypass grafting to the left anterior descending coronary artery in 9 patients and to the right coronary artery in 3 patients using minimally invasive cardiac surgery. The graft to the left anterior descending coronary artery was taken from the left internal thoracic artery in 5 patients, the right gastroepiploic artery in 3 patients, and from the saphenous vein in the other 1 patient. The graft to the right coronary artery was from the right gastroepiploic artery in all 3 patients. RESULTS: All grafts were patent. There was no major postoperative complication and no surgical or hospital death except one late death. CONCLUSIONS: In selected patients, we could safely and completely perform coronary artery bypass re-grafting to the left descending coronary artery or right coronary artery using a minimally invasive operation.

Aged↗
PubMed2001

Fragment-specific actions of parathyroid hormone in isolated perfused rat hearts.

Different regions within the parathyroid hormone (PTH) molecule are known to have different biological activities. In the heart, the physiological actions of the intact PTH molecule are known as positive chronotropy and coronary vasodilatation. However, it is unclear which region of the PTH exerts which physiological action in the heart. Therefore, to clarify this point, we examined the hemodynamic effect of intact PTH(1-84) and selected PTH analogs, namely, PTH(1-34), PTH(2-34), [Nle8, 18Tyr34]PTH(3-34), PTH(4-34), [Tyr34]PTH(7-34), and PTH(13-34) in isolated perfused rat hearts. Both PTH(1-84) and PTH(1-34) significantly increased heart rate and decreased coronary perfusion pressure. In contrast, neither PTH(2-34) nor [Nle8,18Tyr34]PTH(3-34) increased heart rate, but they did decrease coronary perfusion pressure. Peptides further truncated at the amino terminus, PTH(4-34), [Tyr34]PTH(7-34), and PTH(13-34), had no effect on hemodynamics. Furthermore, the protein kinase A inhibitor H89, but not the protein kinase C inhibitor H7, attenuated the hemodynamic effects of PTH(1-34) or PTH(2-34), while it prevented those of [Nle8,18Tyr34]PTH(3-34). These results clearly demonstrate that the first amino acid of PTH is essential for its chronotropic property whereas the first 3 amino acids of PTH are involved in its coronary vasodilatory action. Furthermore, protein kinase A, but not protein kinase C, appears to be involved in the chronotropic and coronary vasodilatory actions of PTH.

Animals↗
PubMed2001

Tracheal allotransplantation maintaining cartilage viability with long-term cryopreserved allografts.

BACKGROUND: Cartilage viability of a cryopreserved tracheal allograft seems to affect graft function and durability. We previously reported the influence of warm ischemia and cryopreservation on cartilage viability of tracheal allografts. For the clinical application of tracheal allotransplantation, it is essential to preserve grafts for a long time. In this study, we assessed cartilage viability of tracheal allografts after long-term cryopreservation in transplantation models. METHODS: The tracheas were harvested from Lewis rats. The grafts were frozen to -80 degrees C in a programmable freezer immediately after being harvested and were then stored in liquid nitrogen (-196 degrees C) for different lengths of preservation (1, 2, 6, 9, 12, 18, and 24 months; n for each group = 8). Cartilage viability was evaluated by estimating proteoglycan synthesis. After harvest or thawing of the tracheas, the cartilage was labeled with 4 muCi/mL of Na2 35SO4. Specimens were then hydrolyzed in 0.5 mol/L NaOH, and a solution of the extracts was then counted by a liquid scintillation counter. 35Sulfur incorporation before and after cryopreservation was examined in each group. Tracheal allotransplantation was performed using Lewis rats as donors and Brown Norway rats as recipients. RESULTS: The average 35S incorporation in the cartilage before cryopreservation was 224 +/- 17 disintegrations per minute per milligram of tissue protein. The average 35S incorporation in the cartilage after cryopreservation decreased to 67% to 76% compared with that before cryopreservation. There were no significant differences among the groups in 35S incorporations after cryopreservation. Histologic examination after transplantation revealed normal tracheal cartilage in all groups. CONCLUSIONS: The viability of tracheal cartilage after cryopreservation decreased to 67% to 76%. There were no significant differences in viability of cartilage among the tracheas after different lengths of cryopreservation. Tracheal allotransplantation after long-term cryopreservation can be safely performed in the rat model.

Animals↗
PubMed2001

Bifidobacterium longum as a delivery system for gene therapy of chemically induced rat mammary tumors.

A fundamental obstacle in cancer gene therapy is the specific targeting of therapy directly to a solid tumor, and no systemic delivery system yet exists. A strain of domestic bacteria, Bifidobacterium longum, which is nonpathogenic and anaerobic, selectively localized to and proliferated in 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors after systemic application. We further ascertained the tumor specificity of genetically engineered, as well as wild-type, Bifidobacterium longum. This is the first demonstration that Bifidobacterium longum can be utilized as a specific gene delivery vector for gene therapy on solid breast tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Effects of milrinone on left ventricular end-systolic pressure-volume relationship of rat hearts in situ.

1. We have already shown that the left ventricular (LV) end-systolic pressure-volume relationship (ESPVR) of rat hearts in situ is an upward convex curve and that LV end- systolic pressure (ESP(mLVV)) and the systolic pressure-volume area (PVA(mLVV)) at a mid-range LV volume (mLVV) sensitively reflect acute changes in LV contractility and work capability. Milrinone is a non-glycosidic, non-sympathomimetic drug that increases myocardial cAMP concentrations by selective inhibition of cardiac phosphodiesterase III. Therefore, milrinone could act on the entire cardiovascular system and cause an increase in inotropy, arterial vasodilatation and venodilatation. The aim of the present study was to investigate whether the approach we have recently instituted is able to detect the effects of milrinone on the entire cardiovascular system. 2. We measured simultaneously, in anaesthetized rats, continuous LV pressure using a catheter-tip micromanometer and LV volume by LV volumetry using a conductance catheter. We obtained steady state LV pressure-volume loops and intermittently obtained the LV ESPVR by gradual occlusion of the ascending aorta. We then evaluated LV function by assessing milrinone-induced changes in the ESPVR (i.e. ESP(mLVV) and PVA(mLVV)) and vasodilator actions by assessing milrinone-induced changes in ESP(ESV) and effective arterial elastance (Ea), defined as the ESP(ESV)/stroke volume ratio. 3. Milrinone (total dose 49.5 microg; infusion rate 3.3-6.7 microg/min, 7-10 microg/kg per min; blood concentration 53.9 ng/mL) largely shifted the ESPVR upwards and, thus, significantly increased end-systolic pressure (ESP(0.08)) and the systolic pressure-volume area (PVA(0.08)) at a mid-range LV volume (= 0.08 mL/g myocardium). Milrinone also significantly decreased LV ESP(ESV) and decreased Ea, although these decreases were not significant. 4. The results of the present study suggest that our own recently instituted approach to evaluate LV function by measuring LV pressure-volume loops and ESPVR succeeded in detecting a cardiotonic action of milrinone with arterial vasodilatation in normal rat hearts.

Animals↗