Search PubMed⌕ Search

Biomedical subjects

K Esato

Publications and source records attributed to K Esato.

At least 73 records · Page 4Linked to original sources
PubMed2000

Changes in left ventricular function after cardiac arrest and reperfusion in hypertropheral hearts.

Hypertrophied hearts may be more susceptible to ischemia/reperfusion during cardiac surgery than normal hearts, so we designed to compare the alterations in left ventricular function after ischemia/reperfusion, in hypertrophied hearts (Group H) with those in normal hearts (Group C), using a rabbit heart model of hypertrophy induced by banding of the ascending thoracic aorta. The pre and postischemic left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), positive and negative dP/dt, and coronary flow were measured. The percent recovery of coronary flow and negative dP/dt were significantly lower in Group H than in Group C (p < 0.05). The LVEDP was significantly greater in Group H, and the LVEDP increased significantly from the base line value in Group H (p < 0.05). There was no significant difference in other value between two groups. These findings demonstrated that LV diastolic dysfunction rather than LV systolic dysfunction occurred in the early ischemic stage, especially to hypertrophied hearts, indicating that better protection is required for these hearts.

Animals↗
PubMed2000

Improvement of contralateral pulmonary function after unilateral lung volume reduction surgery (LVRS).

We evaluated contralateral pulmonary function after unilateral lung volume reduction surgery using pulmonary washout with Xe 133 gas before and 3 months after the operation. Eight patients underwent unilateral lung volume reduction surgery by video-assisted thoracoscopy. Dynamic single photon emission tomography was performed and the real half-time (T1/2) of each lung, defined as the time required to reach 50% of the equilibrium count during washout, was assessed on transaxial images. The preoperative total lung T1/2 was 126+/-12 sec, and this decreased significantly to 97+/-14 sec after surgery (p<0.01). The T1/2 of the operated lung decreased from 124+/-12 sec to 101+/-16 sec, but it increased postoperatively in two patients. The T1/2 of the contralateral lung also decreased significantly from 129+/-14 sec to 88+/-10 sec after surgery, including these two patients (p<0.01). Three patients (including these two) subsequently underwent contralateral volume reduction surgery 3 to 5 months after the first operation. The total lung T1/2 increased in one patient, although it improved slightly in the other two patients after the second operation. Unilateral volume reduction surgery does appear to have some benefit for contralateral pulmonary function. Even when the T1/2 of the operated lung increased postoperatively, the contralateral washout time was improved resulting in improvement of the total lung T1/2. In patients who did not benefit from unilateral volume reduction surgery, subsequent contralateral surgery may fail to improve pulmonary function.

Aged↗
PubMed1999

Impaired respiratory mechanics in pulmonary emphysema: evaluation with dynamic breathing MRI.

To evaluate impaired respiratory mechanics in pulmonary emphysema, dynamic breathing magnetic resonance imaging (BMRI) was acquired with fast-gradient echo pulse sequences at fixed thoracic planes over two to three slow, deep respiratory cycles in 6 controls and 28 patients with pulmonary emphysema including 9 patients undergoing lung volume reduction surgery (LVRS). Respiratory motions of the diaphragm and chest wall (D/CW) were assessed by a cine-loop view, a fusion display of maximal inspiratory and expiratory images, and the time-distance curves. By contrast with normal subjects with regular synchronous D/CW motions, the patients frequently showed reduced, irregular, or asynchronous motions, with significant decreases in the maximal amplitude of D/CW motions (MAD and MACW), and the length of apposition of the diaphragm (LAD) (P < 0.0001, P < 0.001, P < 0. 01, respectively). After LVRS, nine patients showed improvements in D/CW configuration and mobility, with significantly increased MAD, MACW, and LAD (P < 0.01, P < 0.0001, and P < 0.05, respectively). In 40 studies of 28 patients including the post-LVRS examinations, the normalized MAD and MACW significantly correlated with %FEV(1) (r = 0. 881 and r = 0.906; P < 0.0001, respectively). BMRI seems useful for noninvasively and directly assessing the impaired respiratory mechanics associated with abnormal ventilation in pulmonary emphysema, and also for monitoring the effects of LVRS. J. Magn. Reson. Imaging 1999;10:510-520.

Aged↗
PubMed1999

Is a Vein Patch Worthwhile for Femoropopliteal Bypass With ePTFE Grafts?

One of the factors contributing to late graft occlusion after peripheral arterial bypass with prosthetic grafts is anastomotic intimal hyperplasia. The purpose of this study was to evaluate, experimentally and clinically, the effect of placing a vein patch over the site of distal anastomosis of a ePTFE graft in peripheral arterial bypass (DAPP). After heparinization, the infrarenal abdominal aorta in 14 beagle dogs was resected, and an ePTFE graft was interposed between the resected ends. The dogs were divided into a control group without DAPP and a DAPP group. These animals were killed 3 months after surgery. A total of 89 femoropopliteal bypasses using ePTFE grafts, 71 patients were divided into two groups for analysis; namely, a direct suture group without DAPP being the DS group (n = 62 limbs) and a DAPP group with DAPP (n = 27 limbs). The mean follow-up period was 1010 days in the DS group and 302 days in the DAPP group. All the grafts were patent in both groups of dogs. The thrombus adhering to the entire intraluminal surface of the graft defined as the mean thrombus-covering ratio, in the DAPP group was significantly less than that in the control group, although there were no significant differences in the length of proximal or distal intimal ingrowth into the ePTFE grafts between the two groups. The maximal intimal thickness did not differ significantly between the control group and the DAPP group, at 541 +/- 349 µm and 353 +/- 76 µm, respectively. The 1- and 3-year cumulative patency rates of femoropopliteal bypasses were 86% and 71%, respectively, in the DS group, whereas they were both 91% in the DAPP group. Although the numbers of subjects in this study was too limited for a final evaluation, the trend was unmistakable. The findings of this study indicate that DAPP may improve the cumulative patency of femoropopliteal bypasses with ePTFE grafts.http://link.springer-ny.com/link/service/journals/00547/bibs/8n4p193.html</hea

Journal Article↗
PubMed1999

Right axillary arterial perfusion for a ruptured type B aortic dissection: report of a case.

The results of surgical treatment for a ruptured type B aortic dissection remain far from satisfactory. It is believed that additional perfusion from the right axillary artery might be more beneficial than perfusion from only the femoral artery during surgery for a ruptured thoracic aneurysm. The right axillary perfusion is more likely to perfuse the vital organs proximal to the ruptured area, and thus avoid retrograde emboli. In addition, if the open proximal method is performed, then the right axillary perfusion is able to facilitate the evacuation of air from the aortic lumen. We present herein the case of a patient in whom a ruptured type B acute aortic dissection was successfully treated by applying right axillary perfusion through a left thoracotomy.

Aged↗
PubMed1999

The detection of chronic heart graft rejection by 31P NMR spectroscopy.

The usefulness of phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMRS) for detecting heart graft rejection after transplantation has been investigated by several researchers, and it has thus been demonstrated to be a valid technique for detecting acute myocardial rejection. In this study, we investigated the value of 31P NMRS to assess chronic cardiac allograft rejection. Lewis rat hearts were transplanted into the femoral region of F-344 rat recipients which were treated with cyclosporine, 5mg/kg body weight, by a daily intramuscular injection for 30 days beginning on the day of transplantation. The control isografts employed Lewis donors and recipients not given cyclosporine. The ratios of phosphocreatine (PCr) to inorganic phosphate (Pi), beta-adenosine triphosphate (beta-ATP) to Pi, and PCr to beta-ATP were monitored using surface coil 31P NMRS. 31P NMRS was performed 3, 30, and 60 days after transplantation, and the degree of the rejection and arteriosclerosis of the coronary arteries were then assessed histologically. The PCr:Pi and beta-ATP:Pi ratios for the allografts demonstrated a significant decrease on postoperative day (POD) 60 from that on POD 30 (PCr:Pi, P < 0.001; beta-ATP:Pi, P < 0.01). Although a significant difference existed between the isografts and allografts on POD 60 (PCr: Pi, P < 0.01; beta-ATP:P, P < 0.01), no significant difference was found in the PCr:beta-ATP ratio between the allografts and the isografts. On POD 60, the allografts showed significant graft rejection and arteriosclerotic changes in the coronary arteries. These findings therefore demonstrated the effectiveness of 31P NMRS for detecting chronic graft rejection in a rat model.

Adenosine Triphosphate↗
PubMed1999

Cytokine release during hypoxia reoxygenation by Kupffer cells in rats with obstructive jaundice.

The release of cytokine by Kupffer cells during hypoxia/reoxygenation was studied in vitro in male Wistar rats with obstructive jaundice to investigate the kinetics of interleukin-8 (IL-8) release by Kupffer cells during hypoxia/reoxygenation, and to study the influence of endotoxin during the reoxygenation period. The rats were divided into two groups: one that underwent bile duct ligation (group OJ), and one that underwent a sham operation (group C). Kupffer cells were isolated by collagenase digestion and centrifugal elutriation. The cells were first subjected to hypoxia as 95% nitrogen, after which they were given reoxygenation as 95% oxygen. In addition, they were stimulated with lipopolysaccharide (LPS) 0, 1, and 10 ng/ml. In both groups, the levels of IL-8 became increased during the period of hypoxia/reoxygenation, and reoxygenation after hypoxia further intensified IL-8 production. During the period of hypoxia, the IL-8 levels in group OJ were significantly increased compared with those in group C. With the LPS challenge, there was no significant difference in IL-8 levels in either group. In conclusion, obstructive jaundice induces the activation of Kupffer cells, resulting in increased IL-8 production during hypoxia/reoxygenation.

Analysis of Variance↗
PubMed1999

Prediction of graft prolongation by mixed lymphocyte culture following anti-CD4 monoclonal antibody treatment among different donor-recipient combinations.

This study was conducted to examine whether mixed lymphocyte culture (MLC) could be used as a predictor of the efficacy of anti-CD4 monoclonal antibody (MAb) immunosuppression in vivo in a mouse model. C57BL/10 or BALB/c hearts were transplanted into C3H.He recipients. Anti-CD4 MAb administration prolonged graft survival, but there was a clear difference between the two donor-recipient combinations studied, the median survival time (MST) being >100 days in the C57BL/10 --> C3H group, and 17 days in the BALB/c --> C3H group. Anti-CD8 MAb prolonged the survival of C57BL/10 hearts slightly to a MST of 22 days, but the BALB/c hearts were rejected at control rates. Combining anti-CD4 and anti-CD8 antibody therapy prolonged the survival of C57BL/10 hearts indefinitely, but had little effect on the survival of BALB/c grafts, achieving an MST of only 24 days. Next, MLCs were performed in the presence and absence of the MAbs and compared with the graft survival data. The inhibition rates in the MLC, being the C3H lymph node cell responder, correlated well with graft survival. When three kinds of C3H responder cells, namely lymph node (LN) cells, T cells, and CD4+ cells, were examined to determine which was the most suitable for predicting graft survival, the MLC results showed that the responses of LN cells correlated most closely with graft outcome. In conclusion, MLC using LN cells as the responder is a useful tool for predicting allograft survival induced by anti-CD4 MAb therapy.

Animals↗
PubMed1999

An ascending aortic aneurysm caused by giant cell arteritis: report of a case.

A 69-year-old woman was referred to our hospital for investigation of an abnormality detected by a chest roentgenogram, and was subsequently found to have an ascending aortic aneurysm. She had not suffered any symptoms such as headache or polymyalgia rheumatica. Aneurysmectomy and reconstruction of the ascending aorta was performed using cardiopulmonary bypass, and pathological examination of the aneurysmal wall revealed giant cell arteritis (GCA). Preoperatively, she had not suffered any temporal pain, and no signs of inflammation were detected serologically. GCA is a rare cause of aortic aneurysm in the Japanese population, and a brief review of the literature on this unusual entity is presented following this case report.

Aged↗
PubMed1999

Combined right hepatic and retrohepatic caval resection with reconstruction using a polytetrafluoroethylene graft for primary leiomyosarcoma of the liver: report of case.

We present herein the case of a 53-year-old woman who underwent successful surgical treatment for a leiomyosarcoma of the liver that originated from the posterior hepatic segment and involved the retrohepatic inferior vena cava (IVC). A computed tomographic scan and magnetic resonance imaging demonstrated a large tumor, with rich vascularity, in the liver. The IVC was found to be occluded on these scans, which was confirmed by venacavography. The patient underwent a combined right hepatic and caval resection with reconstruction using an expanded polytetrafluoroethylene graft. The tumor consisted of spindle-shaped cells with cigar-shaped nuclei. It also had a moderate degree of cellularity and ten mitotic figures per ten high-power fields. Immunohistologically, desmin and alpha-smooth muscle actin were stained positive in the tumor cells, implying that the tumor was derived from smooth muscle cells. The patient is alive and well 15 months after her operation.

Blood Vessel Prosthesis Implantation↗
PubMed1999

Coronary bypass surgery after renal transplantation.

We report, herein, cases of two renal transplantation patients who underwent coronary artery bypass grafting and discuss the perioperative management of this clinical situation. The first case was a 43-year-old male who underwent coronary artery bypass grafting 50 days after renal transplantation, and the second was a chronic case of a 49-year-old male who underwent coronary artery bypass grafting 17 years after renal transplantation. Prior to the operation, the first patient was continuously administered 2 mg/kg/day of cyclosporin A with the dosage regulated according to the plasma level. The second patient was administered 50 mg/day of cyclophosphamide intravenously instead of an oral dosage of 50 mg/day of azathioprine just prior to the operation. In both patients, perfusion pressure during cardiopulmonary bypass was maintained at approximately 80 mmHg in order to obtain optimal urine output. The CD4/CD8 ratio was monitored for indication of graft rejection, but no remarkable changes were observed perioperatively in either patient. Both patients followed a good clinical course and their postoperative renal function was well maintained. The urine output during cardiopulmonary bypass was 300 ml and 650 ml, respectively. The patients were discharged 15 and 27 days after their operation, respectively. In conclusion, coronary artery bypass grafting can be safely performed in patients who have undergone renal transplantation, if there is appropriate perioperative usage of immunosuppressive agents and maintenance of perfusion pressure during cardiopulmonary bypass.

Adult↗
PubMed1999

Subjective symptoms and prognosis after lung volume reduction surgery in patients with severe pulmonary emphysema.

Lung volume reduction surgery improves symptoms in patients with severe pulmonary emphysema, but patients are not always satisfied surgical results. Our purpose was to determine the profiles and prognosis of unsatisfactory cases of lung volume reduction surgery. A total of 58 patients with advanced symptomatic emphysema underwent thoracoscopic volume reduction of emphysematous lung tissue. Patients subjectively evaluated their condition 3 months after surgery as "better," "same," or "worse" than before surgery. Of these, 30 evaluated themselves as "better" (58%), 17 as the "same" (33%), and 4 (8%) as "Worse." Most patients with vital capacity (VC) exceeding 2,000 mL (percentage of vital capacity for the predicted value (%VC) of > 60%) with upper-lobe-predominant and centrilobular emphysema were satisfied with surgical results. All patients with lower-lobe-predominant or whole-lung panacinar emphysema evaluated their results as "worse." Six late deaths occurred due to pulmonary infection (3), respiratory failure (2), and an unknown sudden cause (1), with most of these patients having preoperative low VC and high postoperative partial carbon dioxide pressure in the arterial blood (PaCO2).

Aged↗
PubMed1999

Nitric oxide release from coronary vasculature before, during, and following cardioplegic arrest.

Nitric oxide (NO) is known as a vasodilatory molecule synthesized by vascular endothelium. The NO-dependent vasodilatory response of coronary artery is impaired after ischemia and reperfusion. In the present study, the release of NO from coronary vasculature was evaluated before and during cardioplegic arrest and after reperfusion. Nine patients undergoing heart surgery were studied. Multidose crystalloid cardioplegics were used for myocardial protection. The coronary affluent and effluent were obtained simultaneously before cardioplegic arrest, at each cardioplegic administration, and after reperfusion; and the levels of nitrite and nitrate, the stable end-products of NO, were measured. The NO release from the coronary vasculature was determined as the difference in the levels of nitrite and nitrate between the coronary effluent and affluent. The level of nitrite/nitrate release from coronary vasculature was 6.8 +/- 3.7 microM before cardioplegic arrest. During cardioplegic arrest the nitrite/nitrate release decreased, reaching 1.3 +/- 1.3 microM (p < 0.05, vs. before cardioplegic arrest) at the fourth administration of the cardioplegic. At 3 to 5 minutes after reperfusion, nitrite/nitrate release further decreased to 0.36 +/- 0.34 microM (p < 0.05, vs. before cardioplegic arrest). During cardioplegic arrest the NO release decreased and reached significance at approximately 70 minutes of cardioplegic arrest compared to that before cardioplegic arrest. After reperfusion, NO release was further reduced, with statistical significance compared to that before cardioplegic arrest. Our data may indicate that cardioplegic arrest and reperfusion cause endothelial dysfunction.

Aged↗
PubMed1999

The preoperative administration of lentinan ameliorated the impairment of natural killer activity after cardiopulmonary bypass.

The aim of this study was to determine whether the preoperative administration of lentinan, which is used clinically to activate T cell function in cancer patients, prevents the impairment of lymphocyte function after cardiopulmonary bypass (CPB). A total of 25 adults undergoing coronary artery bypass grafting were enrolled in this study. Lentinan (2 mg) was given to 10 randomly selected patients 7 d before surgery, while the other 15 patients were considered as a control. The white blood cell count, percentage of lymphocytes, subsets of lymphocytes, and natural killer cell activity were measured preoperatively, immediately after CPB and 1, 3, and 6 d after surgery. The white blood cell counts and the percentage of lymphocytes were not significantly different between the two groups; however, the percentage of CD4-positive cells in the lentinan group recovered to normal more rapidly than in the control group. Although natural killer cell activity was impaired in the control group after CPB, it maintained a nearly normal level in the lentinan group. The preoperative administration of lentinan for patients undergoing CPB ameliorated the impairment of natural killer activity and promoted the rapid recovery of CD4-positive cells.

Adjuvants, Immunologic↗
PubMed1999

Alterations in cardiac sarcoplasmic reticulum Ca2+ regulatory proteins in the atrial tissue of patients with chronic atrial fibrillation.

OBJECTIVES: Our purpose was to determine whether atrial fibrillation (AF) patients have alterations in sarcoplasmic reticulum (SR) Ca2+ regulatory proteins in the atrial myocardium. BACKGROUND: Clinically, AF is the most frequently encountered arrhythmia. Recent studies indicate that an inability to maintain intracellular Ca2+ homeostasis with a consequent increase in membrane-triggered activity could be the primary initiating factor in some circumstances, and that cytosolic Ca2+ abnormalities are an important mediator of sustained AF. METHODS: We measured the maximum number of [3H]ryanodine binding sites (Bmax) and the expression levels of ryanodine receptor (RyR) mRNA and calcium-adenosine triphosphatase (Ca2+-ATPase) mRNA in atrial myocardial tissue from 13 patients with AF due to mitral valvular disease (MVD) and 9 patients with normal sinus rhythm (NSR). RESULTS: In AF patients, 1) Bmax was significantly lower in each atrium (0.21+/-0.03 pmol/mg [right], 0.16+/-0.04 pmol/mg [left]) than in the right atrium (0.26+/-0.08 pmol/mg) of NSR patients; 2) Bmax was significantly lower in the left atrium than in the right atrium; 3) Bmax in the left atrium was significantly lower at higher levels of pulmonary capillary wedge pressure; 4) the expression level of RyR mRNA was significantly lower in both the left (1.24 x 10(-2)+/-1.28 x 10(-2)) and right (1.70 x 10(-2)+/-1.78 x 10(-2)) atrium than in the right atrium of NSR patients (6.11 x 10(-2)+/-2.79 x 10(-2)); and 5) the expression level of Ca2+-ATPase mRNA was significantly lower in both the left (5.67 x 10(-2)+/-4.01 x 10(-2)) and right (7.71 x 10(-2)+/-3.56 x 10(-2)) atrium than in the right atrium (12.60 x 10(-2)+/-3.92 x 10(-2)) of NSR patients. CONCLUSIONS: These results provide the first direct evidence of abnormalities in the Ca2+ regulatory proteins of the atrial myocardium in chronic AF patients. Conceivably, such abnormalities may be involved in the initiation and/or perpetuation of AF.

Aged↗
PubMed1999

Pharmacokinetic differences between rat tumour and lung tissues following isolated lung perfusion with cisplatin.

Isolated lung perfusion has been performed for the treatment of unresectable lung tumours; however, the pharmacokinetics of this procedure remain unclear. This study was conducted to investigate the changes in antitumour drug concentrations in tumour and lung tissues after isolated lung perfusion, using different perfusion times and perfusate drug concentrations. Isolated left lungs were perfused for 20, 40 or 60 min with 25, 50 or 100 micrograms/ml of cisplatin after solitary lung tumour nodules were established in rats, and the total platinum concentrations in the perfused lung and tumour tissues were determined by flameless atomic absorption spectroscopy. The oedema in the perfused lung tissues was evaluated by histological examination and by the wet to dry weight ratios of the lungs. The total platinum concentration increased significantly with perfusion time and increasing perfusate cisplatin concentrations in the lung tissue, but it did not change in the tumour tissue. The wet to dry weight ratios of the lung tissues did not differ significantly among the perfusion groups. Oedema of the perfused lung tissue did not change significantly with the perfusion time or perfusate cisplatin concentration. The results of this study indicate the possibility that different pharmacokinetics exist between tumour and lung tissues following isolated lung perfusion with cisplatin, which could be used as a clinical guide for the selection of appropriate perfusion times and perfusate drug concentrations.

Animals↗
PubMed1999

Coronary arteriovenous fistulas with giant aneurysm: two case reports.

Coronary arteriovenous fistulas are rare, particularly in association with coronary aneurysms. Two rare cases of patients with coronary arteriovenous fistulas and giant aneurysmal formation are described. A right coronary fistula that drained into the superior vena cava was demonstrated in one patient. The remaining patient had a documented left coronary fistula that drained into a main pulmonary artery and had evidence of several plexal vessels that transversed through the pulmonary trunk and toward the pericardial reflex. Under cardiopulmonary bypass, the fistulas and plexal vessels were successfully ligated without any injury to the native coronary circulation.

Adult↗