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Biomedical subjects

M Sonoda

Publications and source records attributed to M Sonoda.

At least 19 recordsLinked to original sources
PubMed2006

Blockade of Angiotensin II type-1 receptor reduces oxidative stress in adipose tissue and ameliorates adipocytokine dysregulation.

Dysregulated production of adipocytokines may be involved in the development of atherosclerotic cardiovascular disease in metabolic syndrome and chronic kidney disease (CKD) associated with metabolic syndrome. The aim of this study was to determine the effects of treatment with angiotensin II (Ang II) type-1 receptor blocker (ARB) on the regulation of adipocytokines. Olmesartan, an ARB, significantly blunted the age- and body weight-associated falls in plasma adiponectin both in genetically and diet-induced obese mice, without affecting body weight, but had no effect on plasma adiponectin levels in lean mice. Olmesartan also ameliorated dysregulation of adipocytokines in obesity, such as tumor necrosis factor-alpha, plasminogen activator inhibitor-1, monocyte chemotactic protein-1, and serum amyloid A3. Olmesartan significantly reduced reactive oxygen species originating from accumulated fat and attenuated the expression of nicotinamide adenine dinucleotide phospho hydrogenase oxidase subunits in adipose tissue. In cultured adipocytes, olmesartan acted as an antioxidant and improved adipocytokine dysregulation. Our results indicate that blockade of Ang II receptor ameliorates adipocytokine dysregulation and that such action is mediated, at least in part, by targeting oxidative stress in obese adipose tissue. Ang II signaling and subsequent oxidative stress in adipose tissue may be potential targets for the prevention of atherosclerotic cardiovascular disease in metabolic syndrome and also in metabolic syndrome-based CKD.

Adiponectin↗
PubMed2006

Successful delivery after the transfer of twice-vitrified embryos derived from in vitro matured oocytes: a case report.

We report here the first case of successful pregnancy and delivery after the blastocyst transfer of twice-vitrified embryos produced following in vitro maturation (IVM) and ICSI. The patient received 5000 IU hCG on day 12 of the treatment cycle, and oocyte retrieval was carried out 36 h after hCG injection. A total of 22 immature oocytes were obtained. Following incubation for 26 h in IVM medium, 15 oocytes (68.2%) reached metaphase II stage. In total, 13 oocytes (86.7%) were fertilized after ICSI with the husband's sperm, and 11 embryos at the pronuclear stage and two cleaved embryos on day 2 were vitrified because of thin endometrial thickness. Eight cryopreserved embryos at the pronuclear stage were warmed and cultured until the day 3 stage. Three embryos were transferred, and three embryos were twice vitrified. Unfortunately, these transferred embryos did not implant. Three twice-vitrified embryos were rewarmed and cultured until the day 5 stage, and two embryos were transferred. The second transfer attempt of twice-vitrified embryos resulted in the full-term delivery of a healthy infant. This case report demonstrates that twice-vitrified embryos, developed using an IVM protocol, retain the developmental competence for full-term, healthy infants.

Adult↗
PubMed2001

Heart rate decline after exercise in patients with hypertrophic cardiomyopathy.

To evaluate the heart rate recovery, submaximal exercise, echocardiographic examination, and Holter monitoring were performed on 30 patients with hypertrophic cardiomyopathy and 11 controls. The time constant of heart rate decline after exercise was calculated. Spectral analysis was performed on Holter recordings. The time constant did not correlate with heart rate, left ventricular end-diastolic pressure, ejection fraction, or wall thickness. There was no correlation between the time constant and any mean spectral indices over 24 hours in patients. However, the time constant correlated with high frequency component in the night. Nocturnal high frequency component in patients with short time constant was significantly less than in those with long time constant, but did not significantly differ from that in controls. In conclusion, the heart rate decline after exercise does not primarily reflect the severity of hypertrophy or hemodynamic impairment but is associated with nocturnal parasympathetic modulation in patients with hypertrophic cardiomyopathy.

Adult↗
PubMed2001

Modulation of reactive oxygen species in endothelial cells by peroxynitrite-treated lipoproteins.

Peroxynitrite has been implicated in the oxidative modification of low-density lipoprotein (LDL) particles, and nitrotyrosine residues in the LDL have been detected in atherosclerotic plaques. Studies have suggested that lipoproteins modified by peroxynitrite lead to the onset of atherosclerotic vascular disease. We therefore prepared in vitro lipoproteins oxidatively modified by peroxynitrite (NO(2)-lipoprotein) and investigated the effect of NO(2)-lipoprotein on the viability of cultured endothelial cells. After exposure of a high-density lipoprotein (HDL) to peroxynitrite, some intermolecular complexes of apolipoproteins in HDL were detected on immunoblotting with monoclonal antibodies against apolipoprotein AI and AII, suggesting that nitration of HDL by peroxynitrite causes intermolecular cross-linking of the apolipoproteins in the particles. Treatment with 1 mM peroxynitrite increased the 3-nitrotyrosine level to 28.5 mmol/mol of tyrosine residues in the prepared NO(2)-HDL, as quantitated by HPLC, and the amount in NO(2)-lipoprotein depended on the peroxynitrite concentration. HDL exhibited a shorter lag phase and the reaction plateaued more rapidly than that with LDL. To clarify whether or not NO(2)-lipoproteins affect the function of endothelial cells, we first examined the viability of cultured human aortic endothelial cells (HAECs) exposed to NO(2)-lipoproteins. Incubation with either NO(2)-HDL or NO(2)-LDL significantly reduced the HAEC viability at 72 h. The results of RT-PCR and Western blotting showed that NO(2)-HDL markedly suppressed at 48 h not only the expressed levels of mRNA and protein but also the activity of catalase in HAECs. In contrast, NO(2)-LDL significantly reduced the expression and activity of Cu(2+),Zn(2+)-superoxide dismutase (CuZn-SOD) in the cells. Neither NO(2)-HDL nor NO(2)-LDL interfered with nitric oxide production or expression of cyclooxygenases and NADPH oxidase in HAECs. Increased radical production in NO(2)-lipoprotein-treated HAECs implied that reactive oxygen species such as superoxide anions and hydroxyl radicals may contribute to the mechanism of the toxic effect induced in endothelial cells by NO(2)-lipoprotein. Overall, NO(2)-lipoprotein may lead to deterioration of the vascular function through these endothelial cell responses.

Arteriosclerosis↗
PubMed2001

Transient but marked ST elevation in precordial leads caused by ischemia of the isolated right ventricular branch.

The present case is a 64 year-old man in whom transient but marked ST elevation was confirmed in the contralateral precordial leads (V1-3) during percutaneous transluminal coronary angioplasty (PTCA) of the proximal right coronary artery, suggesting that the patient had anteroseptal ischemia. The ST elevation persisted even after the balloon was deflated, and no changes in the left coronary artery were detected. In addition, blood flow in the affected area of the right coronary artery was favorable and there was a transient delay only in the right ventricular branch. Once blood flow in the right ventricular branch improved, ST returned to baseline, and when the right ventricular branch was again occluded by the balloon, ST elevation occurred in a reproducible manner. Hence, the electrocardiographic changes in the precordial leads were caused by occlusion of the right ventricular branch. It is rare to observe ST elevation caused by isolated right ventricular branch ischemia.

Angioplasty, Balloon, Coronary↗
PubMed2001

Anthracycline-induced cardiomyopathies evaluated by tissue Doppler tracking system and strain rate imaging.

OBJECTIVES: Anthracycline cardiotoxicity is known to occur from the subendocardial side of the left ventricular wall. Recent advances of tissue Doppler echocardiography may allow the evaluation of anthracycline cardiotoxicity by dividing the left ventricular wall into the subendocardial half and subepicardial half. The present study assessed the feasibility using the tissue Doppler echo tracking system (M-mode) and myocardial strain rate imaging (B-mode) to noninvasively detect anthracycline cardiotoxicity. METHODS: The tissue Doppler echo tracking system (M-mode) was used to measure systolic thickening of the subendocardial layer (delta Endo), subepicardial layer (delta Epi), and whole wall (delta Total) of the left ventricular posterior wall in 41 normal subjects and three groups of patients receiving anthracycline: 34 patients in the low dose group, 19 in the middle dose group, and 12 in the high dose group. Strain rate is the spatial gradient of local velocities, reflecting local compression and expansion rates not affected by overall heart motion. Myocardial strain rate imaging (B-mode) was used in 25 normal subjects, 9 patients in the low dose group, and 10 patients in the high dose group. The ratio of peak systolic strain rate of subendocardium to that of subepicardium (peak strain rate endo/epi), and the ratio of integrated strain rate during ejection time of subendocardium to that of subepicardium (integrated strain rate endo/epi) were measured. RESULTS: Tissue Doppler echo tracking system (M-mode) measurement of delta Endo/delta Epi showed the most distinct difference and the least overlap of the data between normal subjects and patients, whereas delta Total failed to show significant differences. Myocardial strain rate imaging (B-mode) measurement of integrated strain rate endo/epi showed the most distinct difference and the least overlap of the data between normal subjects and patients, but ejection fraction failed to show statistically significant differences. CONCLUSIONS: These methods are highly sensitive tools for monitoring anthracycline cardiotoxicity.

Anthracyclines↗
PubMed2001

[Aneurysm-like wall motion abnormality in hibernating myocardium detected by stress thallium scintigraphy].

A 70-year-old female patient presented and ECG with QS patterns and ST elevation in V1-3. Left ventriculography showed severely abnormal wall motion of the anteroseptal similar to a left ventricular aneurysm. Based on previous experience that 201Tl myocardial scintigraphy revealed possible myocardial viability in a patient with left ventricular aneurysm suspected of having apparently no myocardial viability, percutaneous transluminal coronary angioplasty (PTCA) was performed for severe stenosis of the left anterior descending artery. Follow-up images 3 months later showed a remarkable improvement in parietal motility of the left ventricle and recovery of almost normal cardiac function. This case demonstrates that exercise myocardial scintigraphy is useful for diagnosing hibernating myocardium associated with severely abnormal parietal motility, such as left ventricular aneurysm.

Aged↗
PubMed2001

[Collateral blood flow showing dissection-like filling defect on coronary arteriography: a case report].

A 51-year-old man presented under a diagnosis of angina pectoris manifesting as exertional chest pain. First coronary angiography showed severe stenosis with ulceration and spontaneous dissection at the proximal right coronary artery and linear dissection-like filling defects extending to the distal right coronary artery. After about 3 months, repeat coronary angiography showed the previously observed stenosis with unclear dissection, and better developed collaterals from the left coronary artery to the right coronary artery showing the linear dissection-like filling defects. The bilateral coronary angiography did not clearly show filling defects. This phenomenon suggested that the collateral flows were related to filling of the defects. Intravascular ultrasonic imaging demonstrated severe atherosclerotic lesions at the proximal right coronary artery, but no dissection in the distal right coronary artery. Percutaneous transluminal coronary angioplasty for the stenosis was performed successfully with a stent. Coronary angiography after the angioplasty showed no collaterals, and the right ventricular branch appeared, suggesting that the linear dissection-like filling defects extending to the distal right coronary artery were due to the collateral flows. Filling defects extending distal to a severe stenosis must be distinguished carefully from coronary dissection.

Angioplasty, Balloon, Coronary↗
PubMed2000

Synthesis and association behavior of butadiyne-bridged

Butadiyne-bridged [4(4)](2,6)pyridinophane and [4(6)](2, 6)pyridinophane derivatives were synthesized, and their heteroassociations with the corresponding metacyclophanes and complexations with organic cations were investigated.

Journal Article↗
PubMed2000

Calcineurin is activated in rat hearts with physiological left ventricular hypertrophy induced by voluntary exercise training.

BACKGROUND: Calcineurin may play a pivotal role in the signaling of cardiac hypertrophy; since this hypothesis was first put forward, controversial reports have been published using various experimental models. This study was designed to compare the physiological left ventricular hypertrophy (LVH) induced by voluntary exercise with LVH induced by aortic constriction and to determine whether calcineurin participates in the signaling of exercise-induced LVH. METHODS AND RESULTS: Wistar rats were assigned to 1 of the following 5 groups: 10 weeks of voluntary exercise (EX), a sedentary regimen, a 1-week (AC1) or 4-week (AC4) ascending aortic constriction period, or a sham operation. EX rats ran 2.4+/-0.7 km/day voluntarily in specially manufactured cages; this was associated with an increase of LV diastolic dimension and stroke volume. Myocardial calcineurin activity markedly increased in EX rats (46.4+/-8.3 versus 18.4+/-0.5 pmol. min(-1). mg(-1) in sedentary rats; P<0.001) and in AC1 rats (44.9+/-6.7 versus 22.1+/-3.7 pmol. min(-1). mg(-1) in sham-operated rats; P<0.001), but not in AC4 rats (29.0+/-3.4 pmol. min(-1). mg(-1)). Treatment with cyclosporin A completely inhibited the development of LVH in EX rats, but it only partially attenuated the development of LVH in AC4 rats. CONCLUSIONS: Calcineurin was activated in exercise-induced physiological LVH and in the developing phase of LVH (AC1), but not in decompensated pressure-overload hypertrophy (AC4). Cyclosporin therapy for the prevention of LVH may be harmful because it does not block the development of pathological hypertrophy but rather that of favorable adaptive hypertrophy.

Animals↗
PubMed2000

The effects of hyaluronan on the meniscus in the anterior cruciate ligament-deficient knee.

Anterior cruciate ligament (ACL) deficiency often induces meniscal tears and, ultimately, degenerative joint disease. The hypothesis of this study was that hyaluronan (HA; MW = 8 x 105) may have a protective effect on the medial meniscus following a period of ACL deficiency. The animal model consisted of creating an ACL deficiency by ACL transection (ACLT) in 51 mature New Zealand white rabbits. Postoperative injections started 4 weeks after ACLT to allow the ACL deficiency to create a degenerative change in the meniscus. The first group (n = 26) was injected with HA and the second group (n = 25) was injected with vehicle (phosphate-buffered saline) in their ACL-deficient knees once a week for 5 weeks, in a protocol similar to that used clinically. At the end of the injections, the HA-treated menisci showed a reduced meniscus area histomorphometrically (P<0.01), as well as a decrease in water content (P<0.01) when compared with the vehicle-treated menisci. The matrix composition of the menisci was assessed by the total glycosaminoglycans (GAGs) content, which decreased in the vehicle-treated menisci (P<0.05) but did not decrease in the HA-treated menisci. In our model, a positive effect of HA was observed biochemically on the preservation of the meniscus matrix composition in the ACL-deficient knee.

Animals↗
PubMed2000

Effects of hyaluronan on the healing of rabbit meniscus injured in the peripheral region.

The effect of hyaluronan (hyaluronic acid; HA) on the healing of rabbit meniscus injured in the peripheral region was assessed. A longitudinal tear was created in the peripheral region of the medial meniscus in 20 mature New Zealand white rabbits. One week after surgery, HA was injected into the left knee joint once a week for 5 weeks (HA group), while saline was injected into the right knee (control group). Six and 12 weeks after surgery, gross morphology, histology, and biochemical evaluations were performed. On gross morphological examination, there was evidence of meniscal healing in both groups, but the healing rate of the HA group was significantly higher than that of the control group at 12 weeks. Histologically, meniscal healing started at the tibial portion of the meniscal injury at 6 weeks in both groups, then advanced in the direction of the femoral surface at 12 weeks in the HA group. Biochemically, water and glycosaminoglycan contents did not differ significantly between the two groups. Hyaluronan maintained the healing process of the injured menisci, especially in the femoral surface, up to 12 weeks after injury.

Adjuvants, Immunologic↗
PubMed2000

Nitric oxide-related compounds in patients with congenital heart defects and pulmonary hypertension.

BACKGROUND: The relationship between blood levels of nitric oxide (NO)-related compounds in patients with congenital heart defects (CHD) and degree of pulmonary hypertension (PH) has not yet been described. METHODS: Thirty-six patients (aged 6 months to 19 years) with CHD were divided into three groups on the basis of their hemodynamic characteristics: group 1 (control, n = 5), left-to-right shunt (-) without PH (pulmonary to systemic artery peak pressure ratio, Pp/Ps < 0.4); group 2 (n = 14), left-to-right shunt (+) without PH; group 3 (n = 17), left-to-right shunt (+) with PH (Pp/Ps > 0.4). Blood samples were obtained from the right atrium, pulmonary artery, left atrium or pulmonary capillary wedge and aorta during cardiac catheterization. All NO-related compounds in whole blood were measured by chemiluminescent assay using Sievers NO analyzer. RESULTS: The sampling site had no significant impact on NO-related compound levels. However, the patients with PH (group 3) had significantly higher (P < 0.01) blood levels of NO-related compounds (117.3 +/- 14.7 mumol/L) than the patients without PH (groups 1 and 2, 23.9 +/- 3.2 and 38.4 +/- 4.8 mumol/L, respectively). In addition, pulmonary artery resistance (Rp) values of less than 6 Wood U/m2 were directly correlated with levels of NO-related compounds, whereas Rp values greater than 6 Wood U/m2 were inversely correlated with blood levels of NO-related compounds. CONCLUSION: The present results suggest that the hemodynamic status of the pulmonary circulation in CHD affects, at least partly, blood levels of NO-related compounds.

Adolescent↗
PubMed2000

The long-term effects of hyaluronan during development of osteoarthritis following partial meniscectomy in a rabbit model.

OBJECTIVE: The long-term effect of hyaluronan (HA) on meniscus remodeling and articular cartilage preservation was assessed during the development of osteoarthritis following partial meniscectomy in a rabbit model. DESIGN: Approximately 60% of the region of each medial meniscus of 20 rabbit knees was excised bilaterally. The left knee joint was treated with five weekly intraarticular injections of 0.3 ml of HA, beginning 1 week after surgery. The right control knee was injected with PBS on the same schedule. Six months after surgery, animals were killed and the medial menisci and tibial articular cartilage were evaluated morphologically, histologically and biochemically. RESULTS: Meniscal regeneration was observed as newly synthesized translucent tissue, and image analysis revealed that the amount of this tissue was significantly greater in the HA-treated menisci than in the vehicle-treated menisci. Safranin-O staining and image analysis revealed the increased presence of glycosaminoglycans in the HA-treated menisci relative to vehicle-treated menisci while vascularity and biochemical parameters (hydration, total GAGs and reducible collagen crosslinks) were statistically similar in HA- and vehicle-treated menisci. Gross morphologic grading with India ink revealed a trend for less deterioration of tibial articular cartilage in the HA group (P=0.09) while Mankin's score of the HA-treated tibial articular cartilage was marginally lower than that of the vehicle group (P=0.06). Biochemical assessments showed a trend for higher total GAGs concentration in the HA-treated articular cartilage when compared to the vehicle treatment group (P=0.06). CONCLUSION: The present study has demonstrated that following partial meniscectomy, treatment with hyaluronan can enhance meniscal regeneration and may inhibit articular cartilage degeneration as long as six months post surgery.

Animals↗
PubMed2000

The clinical significance of reversed flow in the main pulmonary artery detected by doppler color flow imaging.

BACKGROUND: Using Doppler color flow imaging, abnormal flow patterns were reported to occur with pulmonary artery (PA) dilation. We have frequently observed red signals in the main PA, suggesting reversed flow (RF) in patients without overt pulmonary hypertension. The clinical implication of these signals has not been extensively studied. PATIENTS AND METHODS: We studied 191 of 412 patients referred for echocardiography (99 men and 92 women; mean +/- SD age, 62 +/- 13 years), in whom the main PA diameter had been adequately measured. If a red signal was observed by color flow imaging, a pulsed Doppler echocardiogram of the red signal was recorded simultaneously. The presence of the red signal was correlated with the PA diameter and the PA systolic pressure determined using the modified Bernoulli equation. In 54 patients who also underwent cardiac catheterization studies, the red signal was correlated with PA and pulmonary capillary wedge (PCW) pressures, and with pulmonary vascular resistance. RESULTS: Red signals adjacent to the medial PA border were detected in parallel with systolic blue signals in 127 patients (66%). Pulsed Doppler recordings revealed that they were caused by RF occurring immediately after the forward systolic signal and persisted in diastole. The PA diameter (28 +/- 4.8 mm) and the estimated PA systolic pressure (34 +/- 16 mm Hg) of patients with the RF signal were significantly greater (p < 0.001 and p < 0.05, respectively) than those of patients without the signal (22 +/- 2.5 mm and 28 +/- 6.0 mm Hg, respectively). Among patients who had hemodynamic studies, PA and PCW pressures were significantly higher (p < 0.05) in the 41 patients with the RF signal (22 +/- 12 mm Hg vs 15 +/- 2.6 mm Hg and 11 +/- 5.5 mm Hg vs 8 +/- 3.1 mm Hg, respectively). CONCLUSION: : RF signals in the main PA occur mostly as a result of PA dilation, which may be caused by primary pulmonary hypertension or chronic elevation of left atrial pressure in left-sided cardiac abnormalities.

Aged↗