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Biomedical subjects

S Taniguchi

Publications and source records attributed to S Taniguchi.

At least 163 records · Page 9Linked to original sources
PubMed1999

Thoracoscopic lung volume reduction surgery for emphysema. Evaluation using ventilation-perfusion scintigraphy.

Thoracoscopic lung volume reduction surgery was conducted in 28 consecutive patients (bilateral 21, unilateral 7). The bilateral procedure was conducted simultaneously in 16 and as a planned staged approach in 5, using stapler resection with Nd:YAG laser ablation. Perfusion and ventilation scintigraphy were used to evaluate status before and after surgery. One operative death (3.6%) due to pneumonia occurred after a simultaneous bilateral procedure. Three to 6 months after surgery, the forced expiratory volume in 1 second (FEV1.0) had improved an average of 44% after the bilateral procedure and 17% after unilateral. Improved ventilation and perfusion distribution in the lower lung field correlated significantly with improved dyspnea scale (p < 0.01). Mean transit time was shortened significantly in each lung field (p < 0.01). Improved mean transit time correlated significantly with improved FEV1.0 and maximum oxygen consumption (VO2max) (p < 0.05). In conclusion, we found that bilateral thoracoscopic lung volume reduction surgery produces short-term functional outcomes superior to those of the unilateral procedure, and should be considered the procedure of choice for most patients. Ventilation and perfusion scintigraphy are useful both in determining target areas for resection and in evaluating lung volume reduction surgery effects.

Aged↗
PubMed1999

Benefits accruing to grafting of the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting.

OBJECTIVES: We have investigated the effects and outcome from grafting the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting. METHODS: We analyzed the findings in 185 patients who underwent coronary artery bypass grafting involving right internal thoracic artery-left anterior descending artery bypass. The survival rate, cardiac events related to the right internal thoracic artery-left anterior descending artery graft, and graft patency were investigated. In cardiac catheterization, the production of nitric oxide from the endothelium of the internal thoracic artery was measured as the plasma nitrite and nitrate levels by the Griess reaction. The reactions to acetylcholine infusion (5 micrograms) in the right internal thoracic artery (n = 4) were compared to those in the left internal thoracic artery (n = 9) grafts. RESULTS: The hospital mortality rate was 0.5%. The actuarial survival rate at 11 years after operation was 98.81%. The rate of freedom from cardiac events at 11 years after operation was 92.08%. The rate of patency of the right internal thoracic artery-left anterior descending artery was 97.0% in 133 patients. Nitric oxide production was calculated as (total nitrite plus nitrate production in response to stimulation by acetylcholine-total nitrite plus nitrate level before acetylcholine load)/(total nitrite plus nitrate level before acetylcholine load). There was no significant difference in changes in plasma concentration in response to acetylcholine stimulation between the right internal thoracic artery-left anterior descending artery and left internal thoracic artery-left anterior descending artery groups (20 +/- 29% versus 5 +/- 10%). CONCLUSIONS: The right internal thoracic artery-left anterior descending artery grafts exhibited good patency and release of nitric oxide in response to acetylcholine loading, similar to left internal thoracic artery-left anterior descending artery grafts.

Coronary Artery Bypass↗
PubMed1999

Functional and molecular evidence for Na(+)-HCO3- cotransporter in human corneal endothelial cells.

Although bicarbonate transport in corneal endothelium has been suggested to be coupled to Na+, the underlying molecular mechanism has not been clarified. In the present study we investigated whether a recently cloned Na(+)-HCO3- cotransporter (NBC-1) is responsible for this process, and, if so, whether the endothelium expresses a separate isoform or one of the other two isoforms that have recently been identified (kNBC-1 from kidney and pNBC-1 from pancreas). Using primers designed for specific and common regions we demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) that both kNBC-1 and pNBC-1 are expressed in cultured human corneal endothelial cells. In addition functional studies with a pH-sensitive fluorescence probe were performed. In the presence of HCO3-/CO2 a pH regulatory process was demonstrated which depends on the presence of Na+ and membrane potential, but is independent of Cl- and is inhibited by the disulfonic stilbene DIDS. These results support the presence of NBC-1 as the major bicarbonate transport system in corneal endothelium.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1999

Minimally invasive direct coronary artery bypass combined with abdominal aortic aneurysm repair.

BACKGROUND: For simultaneously combined coronary artery bypass surgery with infrarenal abdominal aortic aneurysm (AAA) repair, a relatively high operative mortality and morbidity have been reported. METHODS: From February 1998 to December 1998, simultaneous minimally invasive direct coronary artery bypass combined with the AAA repair was performed for 4 patients (3 males, 1 female; mean age, 74+/-7 years). Three were high-risk patients: 2 were over 75 years of age, 2 had respiratory insufficiency, and 1 had severe renal impairment. RESULTS: There were no mortalities. The endotracheal tube was removed within approximately 12 hours, and the postoperative courses were uneventful. During 4+/-4 months of follow-up, there was neither angina recurrence nor other morbidity. CONCLUSIONS: Minimally invasive direct coronary artery bypass combined with AAA repair was safe even for high-risk patients.

Aged↗
PubMed1999

Nuclear matrix protein levels in burn patients with multiple organ dysfunction syndrome.

In this study, we investigated multiple organ dysfunction syndrome (MODS) and nuclear matrix protein (NMP), which is an indicator for apoptosis, in burn patients. The subjects were 17 patients with a total burn surface area (TBSA) of 26% or more. Eight of them had MODS, and nine did not. Seven patients died, and 10 survived. The NMP value in the group with MODS (610 +/- 318 units/ml) was significantly higher than in the group without MODS (82 +/- 31 units/ml). The NMP values of the patients who died (645 +/- 326 units/ml) were significantly higher than in the group who survived (111 +/- 95 units/ml), and they rose significantly as the number of impaired organs increased. Our findings suggested that the NMP level in burn cases associated with MODS was higher when apoptosis developed and larger numbers of organs were impaired.

Adult↗
PubMed1999

Mechanism of inhibition of the Na current by tocainide in guinea-pig isolated ventricular cells.

Tocainide blocked the Na current (I(Na)) in ventricular myocytes in either a tonic or a phasic block manner, having a higher affinity for the inactivated state (K(di) = 18 microM) than for the rested state (Kd(rest) = 606 microM). The degree of phasic block was enhanced and the onset of phasic block was faster with an increase in pulse duration as well as at less-negative holding potential (HP). The recovery-time constant from the phasic block of I(Na) induced by tocainide was independent of either the HP or the removal of fast inactivation. After removal of fast inactivation, tocainide showed the pulse-duration dependency of phasic block but not the voltage dependency. These results suggest that tocainide could bind to the inactivated-state receptor through the hydrophilic pathway and leave the receptor through the hydrophobic pathway, producing the tonic and phasic block of I(Na).

Animals↗
PubMed1999

Inhibitory effects of roxithromycin on tumor angiogenesis, growth and metastasis of mouse B16 melanoma cells.

We examined the effects of roxithromycin, a 14-membered ring macrolide antibiotic, on tumor angiogenesis, tumor growth and metastasis of mouse B16BL6 melanoma cells. The inhibitory effect of roxithromycin on angiogenesis using mouse dorsal air sac model was dose-dependent, and 100 mg/kg of roxithromycin administered intraperitoneally twice a day reduced the dense capillary network area to about 20% of the control. Administration of roxithromycin histologically reduced the development of microvessels and mononuclear cell infiltration. In vivo tumor growth studies demonstrated that intraperitoneal administration of roxithromycin at 20 mg/kg/day and 50 mg/kg/day reduced tumor size of B16BL6 melanoma to about 56% and 33% (experiment 1), 71% and 48% (experiment 2) of that in the respective controls. Roxithromycin also significantly inhibited pulmonary metastasis of B16BL6 cells in a spontaneous system. The inhibitory activities of roxithromycin on angiogenesis, tumor growth and metastasis were compared with those of a potent angiogenesis inhibitor, TNP-470. These data demonstrated that roxithromycin has potent antiangiogenic and antitumor effects and might have possible therapeutic applications.

Air Sacs↗
PubMed1999

Antiangiogenic and antitumor effects of 14-membered ring macrolides on mouse B16 melanoma cells.

We examined the effects of macrolide antibiotics on tumor angiogenesis, tumor growth and metastasis in the B 16BL6 mouse melanoma and C57BL mouse system. Two 14-membered ring macrolide antibiotics, roxithromycin and clarithromycin, significantly reduced the dense capillary network area in a mouse dorsal air sac angiogenesis model, whereas a 15-membered ring macrolide, azithromycin, and a 16-membered ring macrolide, josamycin, did not show any inhibitory effect on angiogenesis at the same dose. Intraperitoneal administration of roxithromycin and clarithromycin at 50 mg/kg/day reduced the tumor size of B 16BL6 melanoma to about 41% and 56%, respectively, of that of the control, and significantly suppressed pulmonary metastasis of B16BL6 cells in a spontaneous system. Azithromycin and josamycin, on the other hand, did not inhibit tumor growth or pulmonary metastasis of B16BL6 cells. Immunohistochemistry revealed that roxithromycin and clarithromycin reduced the tumor vascularity and increased apoptosis of the tumor cells in vivo. These results suggest that 14-membered ring macrolides have antiangiogenic and antitumor effects and might have possible therapeutic applications.

Angiogenesis Inhibitors↗
PubMed1999

Major carbohydrate epitopes in tissues of domestic and African wild animals of potential interest for xenotransplantation research.

We investigated the main glycotopes expressed on the tissues of 44 animal species, including primates, nonprimate mammals, marsupials, birds, and a reptile. Paraffin-embedded tissue sections of kidney, heart, liver, pancreas, lung, brain and intestine of 24 domestic animal species were stained with seven fluorescent-labeled lectins. Testis sections of 20 African wild animal species were tested with the same lectins. Overall, three main immunofluorescence patterns were found in the vascular compartment. First, humans and Old World monkeys express genetically polymorphic ABH antigens and do not express alphaGal. Second, New World monkeys, other mammals, and marsupials do not express ABH antigens, but have large amounts of a genetically monomorphic alphaGal. Third, birds and reptiles do not express either ABH or alphaGal, but have monomorphic betaGal, probably different from the lactosamine precursor of ABH and alphaGal. Epithelial cells producing exocrine secretions also expressed carbohydrate epitopes. The fluorescence patterns of the cells of the exocrine compartment are similar, but not identical, to those expressed in the vascular compartment. All the animals tested have some ABH and betaGal in exocrine tissues, but New World monkeys and lower mammals are the only ones expressing alphaGal in exocrine tissues.

Animals↗
PubMed1999

Multiple autoimmune haemopoietic disorders and insidious clonal proliferation of large granular lymphocytes.

We report a patient with clonal proliferation of CD3+8+TCRalphabeta+ large granular lymphocytes (LGL) presenting multiple episodes of autoimmune cytopenia, including autoimmune neutropenia, idiopathic thrombocytopenic purpura, autoimmune haemolytic anaemia, and pure red cell aplasia. Each disorder appeared separately or as a combination during an 11-year clinical course. The increase of blood CD3+8+TCRalphabeta+ LGL was detected 6 years after the initial diagnosis of cytopenia, but the absolute number of LGL cells was always < 1.0 x 109/l. LGL cells were of monoclonal origin and had a chromosomal abnormality. LGL cells transiently responded to cyclosporine A therapy, which was also effective on all of these autoimmune cytopenias. Accordingly, an undetectable level of proliferation of a clonal LGL population could cause various autoimmune haemopoietic disorders.

Adolescent↗
PubMed1999

Increased synthesis of hyaluronate enhances motility of human melanoma cells.

Hyaluronate plays a unique role in the cancer cell microenvironment. In particular, melanoma is the tumor type in which hyaluronate and hyaluronate recognition have been most closely linked to malignancy. In this study we show that a human melanoma cell line stably transfected with hyaluronate synthase cDNA displays enhanced motility. We used a fixed erythrocyte exclusion assay to isolate subsets of the WM793 human melanoma cell line that expressed either high or low amounts of hyaluronate. A cell line with a high level of hyaluronate on its surface (WM793H) displayed significantly higher cell motility on colloidal-gold-coated coverslips than did a line with a low level (WM793L). Next, in order to directly investigate the effects of hyaluronate on melanoma cell migration, we transfected cDNA encoding mouse hyaluronate synthase HAS1 or HAS2 into the re-cloned human melanoma cell line that produced a low amount of hyaluronate (WM793L) by the lipofection method. Several clonal transfectants differentially producing hyaluronate were obtained. There was a positive correlation between total hyaluronate synthesis and formation of the pericellular hyaluronate-rich matrix. We observed an increase in the migration ability of hyaluronate cDNA (HAS1 or HAS2)-transfected cells compared with control cells on glass plates covered with colloidal gold particles. A migration-inhibition assay with anti-CD44 monoclonal antibody showed blocking of the cell motility. It is speculated that the tumor cells might migrate through a hyaluronate-rich extracellular environment when they invade nearby host tissues and that hyaluronate production by the tumor cells could increase this migration. These results suggest that hyaluronate may play a role in the aggressiveness of human melanoma cells.

Animals↗
PubMed1999

Ubiquitous localization of leukotriene A4 hydrolase in the rat nephron.

BACKGROUND: Leukotriene (LT) B4 is a well-known inflammatory mediator and is implied to play some roles in glomerulonephritis. Although LTA4 hydrolase, a final-step key enzyme to produce LTB4, is located in glomerular mesangial cells, as well as in leukocytes, platelets, and endothelial cells, its precise distribution in the kidney other than in mesangial cells remains unknown. Therefore, we have investigated the localization of mRNA, protein, and enzyme activity of LTA4 hydrolase in the rat kidney. METHODS: Microdissection reverse transcriptase-polymerase chain reaction was used for the determination of LTA4 hydrolase mRNA. The enzyme protein was detected by Western blot, and immunohistochemistry was performed. Finally, LTA4 hydrolase activity and LTB4 were assayed in kidney tissues. RESULTS: LTA4 hydrolase mRNA was detectable in all microdissected nephron segments of the cortex and outer medulla. The corresponding size of approximately 70 kDa protein was shown in descending order in the inner medullary > outer medullary >/= cortical homogenates. The immunohistochemical study demonstrated the ubiquitous presence of the enzyme in all nephron segments of cortex, outer medulla, and inner collecting tubules. LTA4 hydrolase activity was detected in the inner medullary >/= outer medullary >/= cortical tissue homogenates. LTB4 was demonstrated in the inner medullary > outer medullary >/= cortical tissues during the basal condition, and was time-dependently increased by stimulation with arachidonic acid and ionomycin in the cytosolic fraction from outer medulla and in the glomerular suspension. CONCLUSIONS: These results strongly suggest that renal tubular cells as well as glomerular cells have an LTB4-forming potency, which may participate in physiological and pathophysiological roles in the kidney.

Animals↗
PubMed1999

Correlation of the intrinsic clearance of donepezil (Aricept) between in vivo and in vitro studies in rat, dog and human.

1. Donepezil hydrochloride (Aricept) is used for the treatment of Alzheimer's disease. Here the correlation of the intrinsic clearance (Cl(int)) of donepezil between the in vivo and in vitro states was studied in rat, dog and human. 2. In an experiment with 14C-donepezil and human microsomes the routes of metabolism were identified as N-dealkylation and O-demethylation, and no unknown metabolites were detected. 3. The Cl(int) of donepezil in the male rat, female rat, dog and human liver microsomes were 33.7, 13.4, 37.0 and 6.35 microl/min/mg microsomal protein respectively, and sex difference in rat and interspecies difference in the estimated Cl(int) were found. 4. After a single intravenous administration to the male rat, female rat and dog, total plasma clearance (ClP(total)) was 78.6, 29.5 and 88.3 ml/min/kg respectively, and a sex difference was observed in rat. 5. After a single oral administration to the male rat, dog and healthy volunteer, ClP(total) was 140, 105 and 2.35 ml/min/kg respectively, and remarkable differences were observed between animals and man. 6. The contribution of renal clearance to blood clearance (Cl(r)) was low in all species. The predicted in vitro hepatic clearance (Cl(h-pre)) was in the rank order: male rat (15.91 ml/min/kg) > dog (7.96) > female rat (7.67) > human (1.04). Although Cl(h-pre) was underestimated, Cl(h-pre) was significantly correlated with that of ClB(total) in the different animal species and in man, indicating that the in vitro-in vivo ranking order was conserved.

Administration, Oral↗
PubMed1999

Development of primary hypothyroidism with the appearance of blocking-type antibody to thyrotropin receptor in Graves' disease in late pregnancy.

Spontaneous remission of Graves' disease with a decrease of thyroid stimulating antibody (TSAb) activity is commonly observed in pregnancy. In this article, however, a Graves' patient who developed primary hypothyroidism with an appearance of thyroid stimulation-blocking antibody (TSBAb) activity in late pregnancy is reported. A 25-year-old woman presented with clinical and biochemical hyperthyroidism with an elevation of 99mTcO4- thyroid uptake (4.7%; normal range, 0.7%-3.0%) and mildly elevated activity of thyrotropin-binding inhibitory immunoglobulin (TBII; 30.4%). She was euthyroid with normal TBII (8.0%) and TSAb (126%) before pregnancy, when the patient was taking a 5-mg daily dose of methimazole (MMI). MMI was stopped by the patient when she became pregnant. Subsequently, the patient progressed into primary hypothyroidism with a marked elevation of TBII activity (78.4%) in the third trimester of the pregnancy (at that time, TSAb activity was not detected). TSBAb measured 2 weeks later was detected at the activity of 85.0%. Replacement therapy was initiated with levothyroxine (LT4) (0.05-0.1 mg/day), which was discontinued on the 55th day postpartum because of the onset of mild thyrotoxicosis followed by short-term euthyroid state despite high TSBAb activity. Subsequently, because the patient developed primary hypothyroidism 5 months after delivery, replacement therapy with LT4 (0.1-0.125 mg/day) was readministered. Thus, it is suggested that the development of hypothyroidism with the appearance of TSBAb in Graves' patients can occur even in late pregnancy.

Adult↗
PubMed1999

A reverse-sandwich enzyme-linked immunosorbent assay for verocytotoxin 1 and 2 antibodies in human and bovine sera.

A reverse-sandwich enzyme-linked immunosorbent assay (ELISA), in which an antibody is sandwiched by antigens, was established for the titration of antibodies to verocytotoxins (VT) in human and animal sera. This assay has two advantages over a conventional indirect ELISA: (i) higher specificity and sensitivity and (ii) the ability to comparably titrate antibodies from different species. The VT1 (Shiga-like toxin 1) antibody-positive rates were 5% in 202 normal adult humans and 99% in 93 normal cattle at a dairy farm. This ELISA is most suitable for seroepidemiologic studies of infections with VT-producing Escherichia coli in humans and various animal species.

Adolescent↗
PubMed1999

New index for oxygen cost of contractility from curved end-systolic pressure-volume relations in cross-circulated rat hearts.

We have already reported the linear oxygen consumption per beat (VO(2))-systolic pressure-volume area (PVA) relation from the curved left ventricular (LV) end-systolic pressure-volume relation (ESPVR) in the cross-circulated rat heart. The VO(2) intercept (PVA-independent VO(2)) is primarily composed of VO(2) for Ca(2+) handling in excitation-contraction (E-C) coupling and basal metabolism. The aim of the present study was to obtain the oxygen cost of LV contractility that indicates VO(2) for Ca(2+) handling in E-C coupling per unit LV contractility change in the rat heart. Oxygen cost of LV contractility is obtainable as a slope of a linear relation between PVA-independent VO(2) and LV contractility. We obtained a composite VO(2)-PVA relation line at a mid-range LV volume (mLVV) under gradually enhanced LV contractility by stepwise increased Ca(2+) infusion and thus the gradually increased PVA-independent VO(2) values. As a LV contractility index, we could not use E(max) (ESP-V ratio; ESP/ESV) for the linear ESPVR because of the curved ESPVR in the rat LV. A PVA at a mLVV (PVA(mLVV)) has been proposed as a good index for assessing rat LV mechanoenergetics. Since the experimentally obtained PVA(mLVV) was not triangular due to the curved ESPVR, we propose an equivalent ESP-V ratio at a mLVV, (eESP/ESV)(mLVV), as a LV contractility index. This index was calculated as an ESP-V ratio of the specific virtual triangular PVA(mLVV) that is energetically equivalent to the real PVA(mLVV). The present approach enabled us to obtain a linear relation between PVA-independent VO(2) and (eESP/ESV)(mLVV) and the oxygen cost of LV contractility as the slope of this relation.

Animals↗
PubMed1999

Evaluation of passive smoking by measuring urinary trans, trans-muconic acid and exhaled carbon monoxide levels.

No method has yet been established to evaluate the exposure to tobacco smoke in passive smoking (PS). We therefore conducted a study on the possibility that the levels of urinary trans, trans-muconic acid (MA) and the exhaled carbon monoxide (CO) could be indices of the passive exposure to tobacco smoke. The moderate correlation was observed between urinary MA levels and the number of consumed cigarettes per day in smokers. The mean urinary MA level of the PS (+) group was significantly higher than that with the PS (-) group. Among the PS (+) group, the mean MA level in the urine obtained in the afternoon was higher than that obtained in the morning. A high correlation was observed between the exhaled CO levels and the number of consumed cigarettes per day in smokers. Like the urinary MA level, the mean exhaled CO level in the PS (+) group, too, gave a significantly higher level than in the PS (-) group. Because the biological half life of MA (7.5 +/- 0.85 h) was longer than that of CO (3.0 +/- 0.36 h), the measurement of urinary MA level is recommended for evaluating the exposure of passive smoking. The measurement of exhaled CO levels is useful only for chain smokers and nonsmokers with PS just before measurement.

Adult↗