976
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Koga T, Fukazawa M, Suzuki Y, Akima M, Adachi Y, Tamura K, Kato T, Kuromaru O. The protective effects of CP-060S on ischaemia- and reperfusion- induced arrhythmias in anaesthetized rats. Br J Pharmacol 1998; 123:1409-17. [PMID: 9579737 PMCID: PMC1565298 DOI: 10.1038/sj.bjp.0701742] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
1. CP-060S is a novel sodium and calcium overload inhibitor, and is also characterized as a calcium channel blocker. As these activities have each been shown independently to ameliorate ischaemia damage in the myocardium, the combination may synergistically exert cardioprotection. In this study, therefore, the protective effect of CP-060S against ischaemia- and reperfusion-induced arrhythmia was evaluated in anesthetized rats. 2. Rats were anaesthetized with pentobarbitone, and the left anterior descending coronary artery was occluded for either 5 min with subsequent reperfusion (a reperfusion-induced arrhythmia model) or 30 min without (an ischaemia-induced arrhythmia model). All drugs were intravenously administered 1 min before the onset of occlusion. 3. In the reperfusion-induced arrhythmia model, the animals in the vehicle-treated group exhibited ventricular tachycardia (VT) in 100%, ventricular fibrillation (VF) in 89%, and death caused by sustained VF in 56%. CP-060S (30-300 microg kg(-1)) dose-dependently suppressed the incidences of arrhythmias. Significant decreases occurred at 100 microg kg(-1) in VF (incidence: 42%) and mortality (8%), and at 300 microg kg(-1) in VT (50%), VF (33%) and mortality (8%). This protective effect of CP-060S was 10 times more potent than that of a pure calcium channel blocker, diltiazem (30-1000 microg kg(-1)) we tested, in terms of effective dose ranges. As both drugs decreased myocardial oxygen consumption estimated by rate-pressure product to a similar extent, the calcium channel blocking activity of CP-060S would not seem to be sufficient to explain its potency. 4. In the same model, co-administration of ineffective doses of diltiazem (300 microg kg(-1)) and a sodium and calcium overload inhibitor, R56865 (100 microg kg(-1)), produced significant suppression of VT (incidence: 62%), VF (46%) and mortality (8%). By contrast, co-administration of R56865 at the same dose with CP-060S (300 microg kg(-1)) did not add to the effect of a single treatment of CP-060S. 5. In the ischaemia-induced arrhythmia model, CP-060S (300 microg kg(-1)) significantly decreased the incidence of VF from 75% to 29%, whereas diltiazem (1 mg kg(-1)) was ineffective. 6. These results suggest that CP-060S inhibits both ischaemia- and reperfusion-induced arrhythmia. The combination of the calcium channel blocking effect and the calcium overload inhibition was hypothesized to contribute to these potently protective effects.
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977
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Tamura K, Tsuji H, Nishiue T, Yajima I, Higashi T, Iwasaka T. Determinants of heart rate variability in chronic hemodialysis patients. Am J Kidney Dis 1998; 31:602-6. [PMID: 9531175 DOI: 10.1053/ajkd.1998.v31.pm9531175] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To clarify determinants of heart rate variability in hemodialysis patients, we evaluated 187 patients receiving chronic hemodialysis. Ambulatory electrocardiogram was recorded for 24 hours from the beginning of hemodialysis. Standard deviation of the normal RR interval (SDNN) was used as a marker of heart rate variability. Multiple regression analysis was performed to select independent variables associated with SDNN from the following 14 variables: age, sex, body mass index before hemodialysis, presence of ischemic heart disease, diabetic nephropathy as primary renal disease, smoking, duration of hemodialysis, mean blood pressure before hemodialysis, left ventricular mass index and fraction shortening in echocardiography, use of beta blockers, use of angiotensin-converting enzyme inhibitors, hematocrit, and blood urea nitrogen. Older age (P < 0.0001), presence of diabetic nephropathy as primary renal disease (P < 0.0001), lower hematocrit (P = 0.0121), larger body mass index before hemodialysis (P = 0.0133), longer duration of hemodialysis (P = 0.0200), and smoking (P = 0.0350) were associated with reduced SDNN. In hemodialysis patients, SDNN as a marker of cardiac autonomic modulation was associated with hematocrit, body mass index, and duration of hemodialysis, in addition to previously reported variables.
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978
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Kimura N, Yoshida T, Nagano M, Tamura K. Importance of T-cell receptor delta-chain gene analysis on CD7+ and CD56+ myeloid/natural killer cell precursor acute leukemia. Blood 1998; 91:2622-4. [PMID: 9516168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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979
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Nosaka S, Yamauchi M, Sasaki T, Hanada T, Tamura K. [A case of traumatic lung cyst]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1998; 51:259-61. [PMID: 9528238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Traumatic lung cyst is an uncommon lung injury due to closed chest trauma. A 5-year-old boy was admitted to our hospital after being run over by motor vehicle. Computed tomography of the chest demonstrated multiple cystic lesions. This case was diagnosed as traumatic lung cysts. Computed tomography taken 37 days after initial injury showed complete resolution of the cysts. Computed tomography was useful in diagnosing traumatic lung cyst and following its clinical course.
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980
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Abe D, Yanagawa K, Yamanobe K, Tamura K. Assessment of middle-distance running performance in sub-elite young runners using energy cost of running. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1998; 77:320-5. [PMID: 9562360 DOI: 10.1007/s004210050340] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The purpose of this study was to assess the validity of v(amax) as an indicator of middle-distance running performance in sub-elite young runners, v(amax) being defined as the quotient maximal oxygen uptake (VO2max) divided by the net energy cost of running (Cr) on a treadmill at a submaximal running velocity (280 m x min[-1]). The VO2max, ventilatory threshold, v(amax), and Cr were assessed in 39 young male sub-elite runners having only small variations in performance level. The relationship between each variable and running performance (at 1500 m, 3000 m, and 5000 m) was evaluated. A trend toward a negative correlation existed between Cr and performance although this was not significant. The VO2max and v(amax) were significantly related to performance. The v(amax) accounted for around 50% of the variability in performance whereas other physiological variables selected in this study were responsible, at best, for approximately 39%. The results presented in this study suggested that v(amax) was a useful indicator of middle-distance running performance in sub-elite young runners with similar performance levels as well as in top elite athletes.
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981
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Suzuki Y, Tamura K, Akima M, Adachi Y, Fukazawa M, Kato T. CP-060S, a novel cardioprotective drug, limits myocardial infarct size in anesthetized dogs. J Cardiovasc Pharmacol 1998; 31:400-7. [PMID: 9514185 DOI: 10.1097/00005344-199803000-00011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The myocardial infarct size (IS)-limiting effect of CP-060S, a novel cardioprotective drug that prevents Na+-, Ca2+-overload and has Ca2+ channel-blocking activity, was compared with that of diltiazem, a pure Ca2+ antagonist, to determine whether the prevention of Na+-, Ca2+-overload contributes to this IS-limiting effect. Dogs were subjected to 90 min of left circumflex coronary artery (LCx) occlusion followed by 5 h of reperfusion. Either CP-060S (300 microg/kg) or diltiazem (600 microg/kg) was administered intravenously 20 min before the occlusion. CP-060S significantly limited IS compared with that of vehicle (percentage of the area at risk: vehicle, 50.64 +/- 6.08%; CP-060S, 21.13 +/- 3.75%; p < 0.01 vs. vehicle). Although diltiazem exerted a significant decrease in rate-pressure product (RPP; an index of myocardial oxygen consumption) during occlusion equal to that of CP-060S, diltiazem did not significantly reduce IS (33.90 +/- 4.30%). Regional myocardial blood flow (RBF) was not significantly different between any of the groups. Therefore the IS-limiting effect of CP-060S cannot be explained in terms of changes in RPP or RBF. Thus the IS limitation induced by CP-060S is probably the consequence of a direct cardioprotective effect on myocytes. The prevention of Na+-, Ca2+-overload may be the primary reason for this IS-limiting effect.
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982
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Kohno I, Takusagawa M, Yin D, Okutani M, Mochizuki Y, Sano S, Ishihara T, Ishii H, Ijiri H, Komori S, Tamura K. QT dispersion in dipper- and nondipper-type hypertension. Am J Hypertens 1998; 11:280-5. [PMID: 9544867 DOI: 10.1016/s0895-7061(97)00474-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The aim of this study was to identify the relationship of QT dispersion on 12-lead electrocardiograms and left ventricular mass index on echocardiograms associated with the circadian rhythm of blood pressure (BP). Heart rate and BP were monitored every 30 min for 48 h in 62 patients with essential hypertension using an ambulatory BP monitoring device. The patients were divided into four groups according to gender and circadian BP pattern (nocturnal BP dipper or nondipper). The patients were classified as dippers if their daytime BP decreased by at least 10% during the night and all the other subjects were classified as nondippers. Age, body mass index, and 48-h mean BP were similar among the four groups. During the night-rest period, the systolic and diastolic BP were significantly decreased in dipper-type hypertensives. The maximum QTc interval and QTc dispersion were longer in nondippers than in dippers. Left ventricular mass index (LVMI) had a tendency to increase in nondippers. The nocturnal reduction of BP significantly correlated with QTc dispersion and LVMI. The QTc dispersion significantly correlated with LVMI and interventricular septum thickness.
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983
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Takahashi K, Miyake N, Ohta T, Akiba Y, Tamura K. Changes in plasma alpha 1-acid glycoprotein concentration and selected immune response in broiler chickens injected with Escherichia coli lipopolysaccharide. Br Poult Sci 1998; 39:152-5. [PMID: 9568314 DOI: 10.1080/00071669889547] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
1. Changes in plasma alpha 1-acid glycoprotein (AGP) concentration and immune responses following Escherichia coli lipopolysaccharide (LPS) injection were studied in broiler chickens. 2. Higher plasma AGP concentrations were observed from 12 to 48 h after a single injection of LPS. 3. The highest concentration of plasma AGP was observed on day 2 followed by a gradual decrease in chicks injected with 150 micrograms/kg body weight of LPS every day for 13 d. 4. Plasma AGP concentration in chicks injected daily with LPS at 900 micrograms/kg body weight for 13 d increased on day 2, and decreased on day 4 to the concentration found before the injection. The concentration increased again on day 10. 5. Changes in plasma interleukin-1 (IL-1) like activity were similar to those in plasma AGP concentration when LPS was injected daily at 900 micrograms/kg body weight for 3 d. 6. Responses of blood mononuclear cell (MNC) proliferation to mitogen or concanavalin A, (Con A), and pokeweed mitogen (PWM) were positively correlated with changes in plasma AGP concentration. 7. The results suggest that plasma AGP concentration could be used as a positive indicator of changes in blood MNC proliferation to a mitogen and in plasma IL-1 like activity.
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984
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Umemura S, Kihara M, Sumida Y, Yabana M, Ishigami T, Tamura K, Nyui N, Hibi K, Murakami K, Fukamizu A, Ishii M. Endocrinological abnormalities in angiotensinogen-gene knockout mice: studies of hormonal responses to dietary salt loading. J Hypertens 1998; 16:285-9. [PMID: 9557921 DOI: 10.1097/00004872-199816030-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Physiological roles of the renin-angiotensin system in maintaining blood pressure and sodium-water balance in angiotensinogen gene-knockout mice were evaluated with special reference to endogenous pressor substances. METHODS Angiotensinogen-gene knockout mice and control mice were fed a 0.3 or 4% NaCl diet for 2 weeks. Systolic blood pressure and urinary excretions of electrolytes, creatinine, aldosterone, adrenaline, noradrenaline, dopamine and vasopressin were measured. RESULTS About 60% of our angiotensinogen-gene knockout mice did not survive until weaning. These mice presented with hypotension and polyuria. Urinary excretion of aldosterone from such mice was significantly lower (not detected) than that from control mice (2.0+/-0.3 pg/mg creatinine). In contrast, urinary excretion of vasopressin from angiotensinogen-gene knockout mice (0.7+/-0.1 ng/mg creatinine) was greater than that from control mice (0.3+/-0.1 ng/mg creatinine), and those of adrenaline and of noradrenaline were similar for knockout and control mice. After salt loading (a 4% NaCl diet), angiotensinogen-gene knockout mice exhibited a significant increase in systolic blood pressure (from 68.3+/-2.9 to 95.9+/-5.9 mmHg), significant decreases in urinary excretions of adrenaline (from 65+/-8 to 40+/-7 pg/mg creatinine) and noradrenaline (from 467+/-48 to 281+/-41 pg/mg creatinine) and no change in excretion of vasopressin compared with such mice fed a 0.3% NaCl diet CONCLUSION The present results with angiotensinogen-gene knockout mice confirm that the renin-angiotensin system plays fundamental roles in maintaining the blood pressure and sodium-water balance. Because the vasopressin and catecholaminergic systems may be altered by lack of angiotensin in angiotensinogen-gene knockout mice, these systems perhaps are not able to restore blood pressure and sodium-water depletion to normal levels in these mice.
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985
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Nosaka S, Yamauchi N, Sasaki T, Hanada T, Tamura K. [Clinical study of synchronous double cancers of the lung and digestive tract]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1998; 51:400-2. [PMID: 9594500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Among 64 cases of surgically resected primary lung cancer from 1991 to 1997, there were 5 cases of synchronous double cancers of the lung and digestive tract. They were consisted of 4 males and 1 female and the patient age at the time of the lung resection ranged from 65 to 81 years (average: 74.6). One male was diagnosed as having lung cancer (squamous cell carcinoma) along with sigmoid colon cancer (adenocarcinoma) and others were lung cancer (adenocarcinoma) and gastric cancer (adenocarcinoma). In two patients with early gastric cancer, lobectomies were performed following endoscopic resection of gastric cancer. In three patients including two old man and woman (over 80 years old), lobectomies and gastrectomies (or sigmoidectomy) were performed at the same time. We omitted mediastinal lymph nodes dissections in two old patients and no operative complications occurred. All patients are alive now. It can be concluded that in cases of synchronous double cancers of the lung and digestive tract, we must select the best treatment that is not invasive for the patient and that simultaneous operation for double cancer can be safely performed.
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986
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Kihara M, Umemura S, Yabana M, Sumida Y, Nyui N, Tamura K, Kadota T, Kishida R, Murakami K, Fukamizu A, Ishii M. Dietary salt loading decreases the expressions of neuronal-type nitric oxide synthase and renin in the juxtaglomerular apparatus of angiotensinogen gene-knockout mice. J Am Soc Nephrol 1998; 9:355-62. [PMID: 9513897 DOI: 10.1681/asn.v93355] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The present study investigates whether neuronal type nitric oxide synthase (N-NOS) in the macula densa participates in the regulation of renal renin expression during altered dietary salt intake in angiotensinogen gene-knockout (Atg-/-) mice. Wild-type (Atg+/+) and Atg+/+ mice were fed a low-salt (0.04% NaCl), normal-salt (0.3% NaCl), or high-salt (4% NaCl) diet for 2 wk. Histochemical staining for NADPH diaphorase (NADPHd) and renin were analyzed morphometrically. Levels of N-NOS and renin mRNA in renal cortical tissues were determined by reverse transcription-PCR and Northern blot analysis, respectively. In animals fed a normal-salt diet, the renal expressions of N-NOS and renin were markedly increased in Atg-/- mice compared with Atg+/+ mice. When mutant mice were fed a high-salt diet, the signal intensity of the NADPHd reaction and the number of positively stained macula densa cells were significantly decreased. The levels of renal cortical N-NOS mRNA were also suppressed by the treatment. These changes were paralleled by decreases in renal renin-immunoreactive areas and the levels of renin mRNA. On the other hand, salt restriction did not produce further significant increases in the renal N-NOS and renin expressions in mutant mice, whereas a parallel inverse relationship was observed between these enzyme expressions and the levels of salt intake in wild-type mice. These results suggest that the N-NOS expression in the macula densa is inversely regulated by salt intake and that the enzyme activity is functionally linked to renal renin production. Salt-modulated renal N-NOS and renin expressions are independent on angiotensin formation in Atg-/- mice.
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987
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Sumida Y, Umemura S, Kobayashi S, Kihara M, Tamura K, Ishigami T, Ochiai H, Chiba E, Nyui N, Ishii M. Angiotensin II receptors in cardiac left ventricles of Dahl rats. Clin Exp Pharmacol Physiol 1998; 25:252-6. [PMID: 9590578 DOI: 10.1111/j.1440-1681.1998.t01-16-.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1. Dahl Iwai salt-sensitive (DS) rats have been reported as becoming hypertensive with left ventricular hypertrophy (LVH) and heart failure when on a high-salt diet. Their circulating renin-angiotensin system (RAS) has been reported to be suppressed. To evaluate the role of angiotensin II (AngII) type 1 and type 2 receptors (AT1 and AT2, respectively) in LVH, we compared cardiac AT1 and AT2 receptors in 10-week-old DS rats and Dahl Iwai salt-resistant (DR) rats. 2. Seven pairs of 6-week-old male DS and DR rats were fed either a low- or high-salt diet (0.3 or 8% NaCl, respectively) for 4 weeks. Left ventricular AngII receptors were measured by radioligand binding assays using [125I]-[Sar1,Ile8]-AngII in plasma membrane fractions from these four groups. The AT1 and AT2 receptors were distinguished using their specific antagonists CV 11974 and PD 123319, respectively. 3. The high-salt diet increased blood pressure and the left ventricle:bodyweight ratio in DS rats. However, neither Bmax for AT1 and AT2 receptors nor Kd for [125I]-[Sar1,Ile8]-AngII differed between the groups. These results are different from those of other reports of pressure-overload LVH, such as spontaneously hypertensive rats or renovascular hypertension rats, in which AT1 and AT2 receptors were reported to be up-regulated.
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MESH Headings
- Animals
- Binding, Competitive
- Blood Pressure/drug effects
- Hypertension/complications
- Hypertension/metabolism
- Hypertrophy, Left Ventricular/complications
- Hypertrophy, Left Ventricular/metabolism
- Male
- Rats
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/drug effects
- Receptors, Angiotensin/metabolism
- Sodium, Dietary/administration & dosage
- Sodium, Dietary/pharmacology
- Up-Regulation
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988
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Kihara M, Umemura S, Sumida Y, Yokoyama N, Yabana M, Nyui N, Tamura K, Murakami K, Fukamizu A, Ishii M. Genetic deficiency of angiotensinogen produces an impaired urine concentrating ability in mice. Kidney Int 1998; 53:548-55. [PMID: 9507198 DOI: 10.1046/j.1523-1755.1998.00801.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Angiotensinogen gene-knockout (Atg-/-) mice lacking angiotensin II exhibit chronic hypotension. The present study was designed to investigate pathophysiology of Atg-/- mice from the renal functional view. Wild-type (Atg+/+) and Atg-/- mice at 10 weeks of age were housed in metabolic cages for 24-hour urine collection. When provided free access to water, Atg-/- mice showed an increased urine output and a decreased urine osmolality compared with Atg+/+ mice. Urinary excretion and plasma levels of vasopressin were significantly higher in mutant mice than in wild-type mice. On the other hand, urinary excretion of aldosterone in mutant mice was suppressed to the levels under the detection limit of the assay system. The mean plasma aldosterone level of Atg-/- mice was suppressed to 30% of that of Atg+/+ mice. Plasma levels of creatinine, endogenous creatinine clearance, and urinary electrolyte excretion were not different between these mice. In Atg+/+ mice, urine osmolality was markedly increased from 1929 +/- 21 to 3314 +/- 402 mOsm/kg during water deprivation, whereas this parameter in Atg-/- mice did not change significantly (from 1413 +/- 121 to 1590 +/- 92 mOsm/kg). Urinary vasopressin excretion increased during water deprivation from 0.24 +/- 0.04 and 0.70 +/- 0.08 to 0.42 +/- 0.06 and 2.31 +/- 0.35 ng/mg creatinine in wild-type and mutant mice, respectively. Histologic study revealed interstitial inflammation, and atrophic changes in the tubules and papilla in Atg-/- mice. In conclusion, a genetic deficiency of angiotensinogen produced an impaired urine concentrating ability and tubulointerstitial lesions, indicating the critical role of angiotensinogen in developing normal tubular function and construction.
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989
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Tamura K, Umemura S, Nyui N, Hibi K, Watanabe Y, Kobayashi I, Sumida Y, Ishigami T, Kihara M, Yabana M, Takagi N, Ishii M. Regulation of cardiac angiotensinogen mRNA in vivo and in vitro. Heart Vessels 1998; Suppl 12:205-8. [PMID: 9476584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this study, to investigate the mechanism of hypertension-associated induction of cardiac angiotensinogen in vivo and in vitro, we studied the regulation of angiotensinogen mRNA in the hearts of genetically hypertensive rats and in the rat cardiomyocytes. Levels of cardiac angiotensinogen mRNA were significantly increased in the hypertensive rats. Steady state mRNA levels for angiotensinogen mRNA in cardiomyocytes were increased by angiotensin II and mechanical stretch. The addition of an angiotensin II type 1 receptor antagonist (CV11974) and a transcriptional inhibitor (actinomycin D) completely blocked the induction of angiotensinogen mRNA by angiotensin II in cardiomyocytes. The addition of CV11974 significantly, but not completely, inhibited the induction of angiotensinogen mRNA by mechanical stretch. Actinomycin D completely blocked the induction of angiotensinogen mRNA by stretch in cardiomyocytes. An angiotensin II type 2 receptor antagonist (PD123319) and a protein synthesis inhibitor (cycloheximide) did not affect the induction. These results indicate that the expression of cardiac angiotensinogen mRNA is activated by the development of hypertensive cardiac hypertrophy, and that angiotensin II and mechanical stretch activates the angiotensinogen gene via the angiotensin II type 1 receptor-pathway in cardiomyocytes.
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990
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Yokomise H, Satoh K, Ohno N, Tamura K. Autoblood plus OK432 pleurodesis with open drainage for persistent air leak after lobectomy. Ann Thorac Surg 1998; 65:563-5. [PMID: 9485276 DOI: 10.1016/s0003-4975(97)01309-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Prolonged air leak with dead space after lobectomy was successfully treated with autoblood plus OK432 pleurodesis in 10 patients. We tried this method for the purpose of (1) reduction of dead space and (2) effective chemical sclerosis. This easy method was associated with acceptable side effects and should be considered as an option for the treatment of prolonged air leak after lobectomy, especially with dead space.
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991
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Kobayashi N, Tamura K, Aotsuka T, Katakura H. Molecular phylogeny of twelve Asian species of epilachnine ladybird beetles (Coleoptera, Coccinellidae) with notes on the direction of host shifts. Zoolog Sci 1998; 15:147-51. [PMID: 9615625 DOI: 10.2108/zsj.15.147] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We determined the nucleotide sequences of a part of the mitochondrial cytochrome c oxidase I gene (1,000 bp) for twelve species of Asian phytophagous ladybird beetles belonging to the genus Epilachna, and constructed molecular phylogenetic trees for ten "Henosepilachna" species, using two "Epilachna" species as outgroups. Based on the suggested phylogenetic trees, we discussed taxonomic issues and the direction of host shift in these epilachnines.
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992
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Suzuki Y, Tamura K, Adachi Y, Fukazawa M, Kato T. CP-060S interacts with three principal binding sites on the L-type Ca2+ channel. Eur J Pharmacol 1998; 342:347-51. [PMID: 9548407 DOI: 10.1016/s0014-2999(97)01496-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CP-060S, (-)-(S)-2-[3,5-bis(1,1-dimethylethyl)-4-hydroxypheny1]-3-[3-[N-met hyl-N-[2-(3,4-methylenedioxyphenoxy)ethyl]amino]propyl]-1,3-thi azolidin-4-one hydrogen fumarate is a novel cardioprotective drug, which is able to prevent Na+-, Ca2+-overload and also has Ca2+ channel blocking activity. The latter action of CP-060S was characterized by radioligand binding experiments with rat cardiac membranes in terms of the interaction with the three principal binding sites on the L-type Ca2+ channel, which bind such drugs as the 1,4-dihydropyridines, phenylalkylamines and benzothiazepines. CP-060S exhibited complete and concentration-dependent inhibition of [3H](+)-PN200-110, [3H](-)-desmethoxyverapamil and [3H]cis-(+)-diltiazem binding to their specific binding sites. Saturation studies showed that CP-060S increased the Kd of [3H](+)-PN200-110 and [3H](-)-desmethoxyverapamil without causing a significant change in the maximum binding density. The dissociation kinetics of the three radioligands were accelerated by CP-060S. These results suggest that CP-060S interacts with a novel binding site on the L-type Ca2+ channel and has a negative allosteric interaction with the three principal binding sites for the 1,4-dihydropyridines, phenylalkylamines and benzothiazepines.
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993
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Tamura K, Hatsuta M, Watanabe G, Taya K, Kogo H. Inhibitory regulation of inhibin gene expression by thyroid hormone during ovarian development in immature rats. Biochem Biophys Res Commun 1998; 242:102-8. [PMID: 9439618 DOI: 10.1006/bbrc.1997.7919] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To explore the role of the thyroid gland in ovarian development during the initiation process of puberty, we examined the effects of hypothyroidism on the secretion of ovarian hormones during equine chorionic gonadotropin (eCG)-induced follicle development in immature female rats. Immature rats at 22 days of age were thyroidectomized (Tx) to cause hypothyroidism and then given a single s.c. injection of 5 IU eCG at 26 days of age to induce normal first ovulation. The blood samples were collected at 0, 24, and 48 h after eCG treatment to measure inhibin and estradiol by radioimmunoassay. Serum inhibin and estradiol levels in eCG-primed Tx animals were significantly higher at 24 and 48 h after eCG treatment than those in controls (eCG treated non-Tx rats). The number of healthy follicles larger than 400 microns in diameter and ovarian weight were significantly increased in Tx rats at 48 h after eCG treatment, compared to those in controls. The number of oocytes which are ovulated by an injection of human chorionic gonadotropin (10 IU) was significantly increased on the day after eCG treatment, compared to that of eCG treated non-Tx rats. The increments in both hormones levels, the number of large antral follicles, and ovarian weight in eCG-primed Tx animals were suppressed up to control levels with daily administrations of 5.0 micrograms thyroxine (T4) for 6 days during 22 to 27 days of age. The expression of mRNAs for inhibin alpha and beta A subunits increased in eCG-primed Tx rats at 48 hr after eCG treatment, and the increase in inhibin mRNAs was suppressed by T4 treatment up to control levels. These results clearly demonstrate that thyroid hormone takes part in an inhibitory regulation of ovarian hormonal secretion and folliculogenesis in eCG-primed immature female rats.
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994
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Nio Y, Sato Y, Nagami H, Teramoto M, Inoue Y, Yano S, Sumi S, Tamura K, Fukumoto M. Neoadjuvant chemotherapy of gastric cancer with oral UFT (a mixture of uracil and fturafur) during the waiting period for surgery. Anticancer Res 1998; 18:523-30. [PMID: 9568172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our previous experience has demonstrated that growth of gastric cancer during the waiting period for surgery cannot be neglected, and some patients hope to receive prophylactic treatment to inhibit the growth of tumor until surgery. The present study was designed to assess the clinical benefits of preoperative chemotherapy with oral UFT for gastric cancer during the waiting period for surgery. Fifty patients with gastric cancer (24 early, 25 advanced and 1 recurrent cancers) were treated with oral UFT at 300-600 mg/day for 7-36 days before surgery and the objective responses and the postsurgical survivals were evaluated. In 42 of 50 patients objective responses of primary lesions were assessed by endoscopy or upper gastrointestinal series examination, and 2 CRs, 15 PRs and 25 NCs were seen (40% response). The histological effect was evaluated in 50 patients and the following classifications were made: grade 3 (complete disappearance or necrosis of tumor cells), 2; grade 2 (necrotic changes > 2/3 area), 4; grade 1b (> 1/3 area), 7; grade 1a (< 1/3 area), 15; and grade 0 (no histological changes), 22. A longer period of UFT administration was associated with CR or PR. All the patients underwent gastrectomy (38 curative and 12 palliative gastrectomies): all patients with Stage I-III primary gastric cancer are alive after surgery, and the 50% survival period of the patients with Stage IV cancer was 20 months. The side effects were not serious, including slight myelotoxicity, liver dysfunction and anorexia. It is concluded that preoperative chemotherapy for gastric cancer with oral UFT on outpatient basis may result in down-staging as well as the prevention of tumor growth during the waiting period for surgery without serious side effects.
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995
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Sano S, Yamamoto K, Kohno I, Ishihara T, Umetani K, Sawanobon T, Ijiri H, Komori S, Tamura K. Detection of myocardial ischemia based on QTc dispersion in the dipyridamole stress test. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)81211-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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996
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Mukouyama Y, Hara T, Xu M, Tamura K, Donovan PJ, Kim H, Kogo H, Tsuji K, Nakahata T, Miyajima A. In vitro expansion of murine multipotential hematopoietic progenitors from the embryonic aorta-gonad-mesonephros region. Immunity 1998; 8:105-14. [PMID: 9462516 DOI: 10.1016/s1074-7613(00)80463-x] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The origin of hematopoietic stem cells (HSCs) and their growth factor requirement are poorly understood. Here we describe a new in vitro culture system of the aorta-gonad-mesonephros (AGM) region, where long-term repopulating HSCs first arise. We demonstrate that oncostatin M (OSM) is expressed in the AGM and is absolutely required for the expansion of multipotential hematopoietic progenitors in vitro. In addition, OSM enhances the formation of endothelial cell clusters. Thus, OSM appears to be a key cytokine for the development of multipotential hematopoietic progenitors in the AGM, possibly acting on common precursor cells between HSCs and endothelial cells. By using the AGM culture derived from macrophage colony-stimulating factor (M-CSF)-deficient op/op mutant embryos, we also show a pivotal role for M-CSF in fetal myelopoiesis.
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997
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Sumida Y, Umemura S, Tamura K, Kihara M, Kobayashi S, Ishigami T, Yabana M, Nyui N, Ochiai H, Fukamizu A, Miyazaki H, Murakami K, Ishii M. Increased cardiac angiotensin II receptors in angiotensinogen-deficient mice. Hypertension 1998; 31:45-9. [PMID: 9449389 DOI: 10.1161/01.hyp.31.1.45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two subtypes of angiotensin II (Ang II) receptors, type 1 (AT1-R) and type 2 (AT2-R), have been identified in the heart. However, little is known about the regulation of cardiac AT1-R and AT2-R by Ang II in vivo. Thus, we examined cardiac AT1-R and AT2-R in angiotensinogen-deficient (Atg-/-) mice that are hypotensive and lack circulating Ang II. Cardiac Ang II receptors (Ang II-R) were assessed by radioligand binding with 125I-[Sar1,Ile8]-Ang II in plasma membrane fractions. AT1-R and AT2-R were distinguished using their specific antagonists CV-11974 and PD123319, respectively. Total densities of Ang II-R and AT1-R density were significantly greater in the Atg-/- mice than Atg+/+ mice (31.1+/-2.8 versus 18.8+/-2.1, 28.7+/-3.0 versus 16.9+/-2.3 fmol/mg protein, P<.01, respectively), and AT2-R showed a slight but not significant increase in Atg-/- mice relative to Atg+/+ control animals. Kd values were not different between the two groups. In contrast to binding experiments, levels of Ang II type 1a receptor (AT1a-R) and AT2-R mRNA did not differ between Atg-/- and Atg+/+ mice. These results suggest that lack of Ang II may upregulate AT1-R through translational and/or posttranslational mechanisms in Atg-/- mice.
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998
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Alam MS, Ku K, Yamauchi M, Hashimoto M, Nosaka S, Hossain MS, Masumura S, Nakayama K, Tamura K. Protective effects of nicaraven, a new hydroxyl radical scavenger, on the endothelial dysfunction after exposure of pig coronary artery to hydroxyl radicals. Mol Cell Biochem 1998; 178:237-43. [PMID: 9546605 DOI: 10.1023/a:1006855917392] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recently, we have reported that a new synthetic compound, 1,2bis(nicotinamido)-propane (nicaraven), improved cardiac function following preservation and reperfusion. In this study, we investigated the efficacy of nicaraven as a radical scavenger by using an in vitro model of oxidative stress, to clarify mechanisms of the protective effect of this new compound on reperfusion injury in rat heart. Ring segments of epicardial right coronary arteries (RCA) of pig were suspended in organ chambers and exposed to hydroxyl radicals (.OH), generated (by two different systems) by 0.28 mM FeSO4/0.28 mM H2O2 and DHF/Fe3+-ADP (2.4 mM, 43 nM, and 1.56 uM, respectively) to the bathing solution for 60 min. Prior exposure of the coronary arteries to .OH significantly produced right-ward shift of the dose-response curves of the bradykinin-induced endothelium-dependent relaxations (an increase in the ED50 value for bradykinin by 4.37 and 1.98 times than control in two different .OH generating systems, respectively), but did not affect the maximum relaxation responses. The presence of nicaraven (10(-4) and 10(-5) M) in the .OH generating system, shifted the dose-response curves to bradykinin to the control level, suggesting a significant hydroxyl radical scavenging effect of the drug. These results indicate that nicaraven, a new hydroxyl radical scavenger, exhibits a protective effect on hydroxyl radical-induced endothelial dysfunctions of pig coronary artery.
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999
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Sato N, Takai Y, Iijima K, Tatsumi Y, Takayanagi M, Hagiwara R, Yamazaki T, Otsuka E, Tamura K, Yokoyama M, Aoki T. [Nutritional support in terminal patients--evaluation of 109 cases receiving home parenteral nutrition]. Gan To Kagaku Ryoho 1997; 24 Suppl 4:571-3. [PMID: 9429569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For end-stage patients with malignant disease, home parenteral nutrition (HPN) is an effective and useful treatment in terms of pain control and nutritional support. Therefore, these patients are able to spend their final days at home with their family. In 1990, we started the treatment and have been experienced 109 cases. In this report, we evaluate these cases and which condition or circumstance are necessary to perform HPN for the terminal patients.
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1000
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Kurabayashi H, Kubota K, Take H, Tamura K, Shirakura T. Effects of hyperthermal stress on the ultrastructure of platelets with reference to the localization of platelet peroxidase and fibrinogen in vivo. Am J Hematol 1997; 56:244-7. [PMID: 9395186 DOI: 10.1002/(sici)1096-8652(199712)56:4<244::aid-ajh8>3.0.co;2-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ultrastructure of platelets with the localization of platelet peroxidase and fibrinogen through 3-min 47 degrees C hot-spring bathing was investigated in eight healthy volunteers. The mean sublingual temperature rose about 1.8 degrees C 5 min after the start of bathing. The frequencies of fold, pseudopods, vacuoles, and centralization were increased after bathing. Platelet peroxidase activity was decreased after bathing. Furthermore, fibrinogen was decreased in alpha-granules after bathing. Thus, hyperthermal stress in vivo may activate platelets, resulting in consumption of platelet peroxidase and fibrinogen.
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