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Biomedical subjects

K Fuse

Publications and source records attributed to K Fuse.

At least 73 records · Page 4Linked to original sources
PubMed1998

Growth potential and left ventricular diastolic function in cardiomyoplasty.

BACKGROUND: Dynamic cardiomyoplasty is an experimental operation for advanced heart failure. Current clinical results bring the possibility of its application to children. This study was designed to obtain information about the relationship between cardiomyoplasty and growth of the heart. METHODS: Six beagles, 9 to 10 weeks old, underwent cardiomyoplasty without electric stimulation (cardiomyoplasty group), and another 5 beagles underwent median sternotomy and pericardiotomy (control group). Six months later, weights of hearts, wrapped latissimus dorsi muscles, and unwrapped right latissimus dorsi muscles and pressure-volume relationships were obtained. RESULTS: Wrapped latissimus dorsi muscles weighed 33 +/- 3 g (mean +/- standard deviation), and unwrapped muscles weighed 68 +/- 5 g. The heart weight was 82 +/- 3 g in the cardiomyoplasty group and 89 +/- 7 g in the control group. Left ventricular maximum elastance was 3.8 +/- 0.8 mm Hg/mL in the cardiomyoplasty group and 3.9 +/- 0.9 mm Hg/mL in the control group. End-diastolic pressure versus end-diastolic volume ratios were 0.52 +/- 0.03 and 0.54 +/- 0.05, respectively. Pathologic examination showed fat infiltration and muscle fiber atrophy in the cardiomyoplasty group. CONCLUSIONS: The wrapped latissimus dorsi muscle flaps were growing and the diastolic function was not impaired. This indicates a potentially safe clinical application of dynamic cardiomyoplasty for children.

Adipose Tissue↗
PubMed1998

Platelet protective effect of TAK-029, a novel glycoprotein IIb/IIIa antagonist: an in vitro study.

Previous studies have indicated that exposure of fibrinogen receptors associated with the glycoprotein IIb/IIIa complex contributes to platelet loss during cardiopulmonary bypass. TAK-029 is a newly developed reversible, nonpeptide inhibitor of platelet glycoprotein IIb/IIIa receptors. In this study, we tested the platelet preserving effect of TAK-029 in an in vitro model. The methods included the comparison of the release of beta-thromboglobulin (beta-TG) between a TAK-029 group (n = 5) and a control group (n = 5) in a mock circulation under a shear force generated by a centrifugal pump. To evaluate the degree of beta-TG release, deltabeta-TG/deltaT was calculated where deltabeta-TG is the increase in beta-TG and deltaT is the time. The results showed that the value of deltabeta-TG/deltaT in the TAK-029 group was significantly lower than it was in the control group (4.22 +/- 0.27 x 10(2) ng/ml vs. 7.33 +/- 0.66 x 10(2) ng/ml, respectively). In conclusion, TAK-029 reduced the platelet activation under the shear forces of an in vitro model, suggesting that TAK-029 is a potential candidate for platelet protection during cardiopulmonary bypass.

Blood Platelets↗
PubMed1998

Evaluation of platelet damage in two different centrifugal pumps based on measurements of alpha-granule packing proteins.

Mechanical trauma caused by centrifugal pumps is usually evaluated in terms of hemolysis. However, platelet damage caused by centrifugal pumps has not been studied well. We evaluated platelet damage in 2 different centrifugal pumps, the Medtronic BioMedicus BP-80 and the Terumo Capiox, in vitro and compared the results in terms of hemolysis. To evaluate platelet damage, the rate of increase (RI) for beta-thromboglobulin (beta-TG) and platelet factor-4 (PF-4) were measured by enzyme immunoassay. RI was defined as follows: RI for beta-TG is deltabeta-TG/deltaN and RI for PF-4 is deltaPF-4/deltaN where deltabeta-TG is the increase in beta-TG, deltaPF-4 is the increase in PF-4, and deltaN is the increase of the passing number, which is defined in the following equation: N = Qt/V (t, time; V, priming volume; Q, flow rate). Each pump was tested in a mock circuit for 3 h under a flow rate of 5 L/min and a pressure head of 100 mm Hg using fresh human heparinized blood (n = 5). For comparison, the normalized index of hemolysis (NIH) values were calculated for both pumps. The NIH values did not indicate a significant difference between the Capiox and the BP-80 pumps (Capiox vs. BP-80, 0.0021 +/- 0.0004 vs. 0.0034 +/- 0.0007, NS). However, the RI values for beta-TG and PF-4 in the Capiox were significantly lower than in the BP-80 (beta-TG, 0.198 +/- 0.047 vs. 0.376 +/- 0.049; PF-4, 0.080 +/- 0.014 vs. 0.268 +/- 0.043, p < 0.05). In conclusion, although there was no significant difference between the 2 pumps in terms of hemolysis, the Capiox centrifugal pump induced less platelet damage than the BP-80. The results suggest that measurements of RI for beta-TG and PF-4 are more sensitive parameters than NIH values for evaluating blood cell damage.

Blood Platelets↗
PubMed1997

Successful surgical treatment of a complete traumatic tracheal disruption.

We report a case of a survivor who suffered a complete traumatic disruption of the cervical trachea associated with multiple organ injuries. She underwent an emergent operation including end-to-end anastomosis of the disrupted trachea with pedicled omental coverage to prevent dehiscence and mediastinitis. The postoperative course was uneventful, with hospital discharge on day 36. She returned to her previous lifestyle.

Anastomosis, Surgical↗
PubMed1997

lpr T cells have lower ability to maintain bcl-2 expression ex vivo.

Autoimmune-prone lpr mice develop lymphoproliferative disorders, whereas their lymphocytes show accelerated apoptosis in culture. To elucidate whether the bcl-2 protein, a repressor of apoptosis, is critical to the discrepancy between in vivo and in vitro survival, we examined bcl-2 expression in T cells from +/+ and lpr mice during culture. The expression levels of bcl-2 in cultured T cells from lpr mice were significantly down-modulated compared to those from +/+ mice and freshly obtained T cells. Besides, the reduction of bcl-2 protein levels was inhibited in T cells cultured in the presence of T cell receptor (TCR) signalling. These results suggest that lpr T cells might be susceptible to apoptosis in vitro due to down-modulation of bcl-2 by withdrawal of TCR signalling.

Journal Article↗
PubMed1997

Platelet damage caused by the centrifugal pump: in vitro evaluation by measuring the release of alpha-granule packing proteins.

Platelets are more vulnerable to damage than erythrocytes because platelets are easily activated by contact with extracorporeal circuits and by exposure to shear forces. However, the degree of platelet damage caused by centrifugal pumps is unclear. To evaluate platelet damage in different pumping conditions, the rates of increase for specific proteins in platelet alpha-granules, beta-thromboglobulin (beta-TG), and platelet factor 4 (PF-4) were measured in both in vitro simulated left ventricular assist device (LVAD) and cardiopulmonary bypass (CPB) conditions and compared with the erythrocyte trauma. A flow of 5.0 L/min with deltaP of 100 mm Hg for LVAD (low pressure head condition) and a flow of 5.0 L/min with deltaP of 350 mm Hg for CPB (high pressure head condition) were investigated. Each condition was tested 4 times for 3 h in a mock circuit with a Capiox (Terumo, Tokyo, Japan) centrifugal pump using fresh human blood. Blood was sampled at 1 h intervals, measuring plasma free hemoglobin (fHb), beta-TG, and PF-4. To evaluate the degree of damage, the rates of increase of fHb, beta-TG, and PF-4 were calculated for each condition as deltafHb/deltaN, deltabeta-TG/deltaN, and deltaPF-4/deltaN where deltafHb is the increase in plasma free hemoglobin, deltabeta-TG is the increase in beta-TG, deltaPF-4 is the increase in PF-4, and deltaN is the increase in the passing number. The passing number is defined in the following equation: N = Qt/V where t is the time, V is the priming volume, and Q is the flow rate. There was no significant difference between the 2 conditions (low pressure head condition versus high pressure head condition) in the rate of increase of fHb (0.0035+/-0.0004 vs. 0.0034+/-0.0010 g/100 L, NS). Contrary to this, the rates of increase for specific proteins in platelet alpha-granules in the high pressure head condition demonstrated a significantly higher rate of increase than in the low pressure head condition. The mean rate of increase for beta-TG in the low pressure head condition was 0.22+/-0.03 ng/ml and in the high pressure head condition was 0.51+/-0.05 ng/ml (p < 0.05). The rate of increase for PF-4 in the low pressure head condition was 0.11+/-0.02 ng/ml and in the high pressure head condition was 0.30+/-0.06 ng/ml (p < 0.05). These results suggest that measurements of beta-TG and PF-4 may be more sensitive parameters than hemolysis for evaluating blood cell trauma and that platelets are more vulnerable to mechanical damage by a centrifugal pump than erythrocytes.

Blood Platelets↗
PubMed1997

Pannus resection through the tilting disc prosthesis: successful treatment preserving the prosthesis.

A 59-year-old woman was admitted to our hospital because of heart failure. In 1988, she underwent aortic valve replacement with an Omnicarbon valve and mitral valve replacement with a bioprosthetic valve. She was doing well until July in 1996 when she developed heart failure. Echocardiography revealed massive mitral valve regurgitation, and cinefluoroscopy showed implanted Omnicarbon valve dysfunction with a leaflet opening angle of 35 degrees. At reoperation, it was revealed that pannus formation prevented the valve from functioning well. The pannus was resected through the major orifice, and the leaflet was rotated toward the right anterolateral orientation. The worn bioprosthetic valve was replaced with a mechanical one. Postoperative cinefluoroscopy of the rotated Ominicarbon valve showed the opening angle to be 61 degrees.

Aortic Valve↗
PubMed1997

Unilateral pulmonary edema in a patient with ischemic heart failure.

A 72-year-old woman with a history of anterolateral myocardial infarction was in severe respiratory distress with frothy sputum production. Electrocardiogram and echocardiogram detected evidence of ischemic change due to anterolateral myocardial injury. Chest roentogenogram showed unilateral, right side pulmonary edema with a clear left lung field. Mechanical ventilation and diuretic administration contributed to her recovery from heart failure and pulmonary edema. Computed tomographic scan showed no abnormality of the bilateral lung fields or pulmonary vasculature; however, pulmonary perfusion scan and pulmonary angiography revealed reduced blood perfusion in the entire left lung field. Although we have no histological evidence, some pulmonary parenchymal change on the left side might have been the cause of unilateral pulmonary edema in this case. In conclusion, a woman with ischemic heart failure developed unilateral pulmonary edema on the right side, showing reduced blood perfusion on the left side.

Aged↗
PubMed1997

[Rapid ventricular pacing in dogs--the natural history and pathology].

Six dogs were rapidly paced for 4 weeks with a VVI pacemaker, and observed for 4 to 6 weeks after cessation of rapid pacing. Echocardiographic study revealed congestive heart failure at the end of rapid pacing associated with enlarged left ventricles and reduced left ventricular ejection fraction. Four weeks after cessation of rapid pacing, the left ventricular cavity and ejection fraction improved, but did not return to the normal pre-paced values. Six weeks after the cessation, cardiac function recovered, and pathological study of the resected hearts demonstrated normal myocardium without fibrotic or ischemic changes.

Animals↗
PubMed1997

[Repair of ischemic cardiac rupture and perioperative management with mechanical circulatory assist].

Fifteen cases with ischemic cardiac rupture were reviewed. Three cases with subacute free wall rupture of the left ventricle, ten with ventricular septal perforation, and one with both ventricular septal perforation and blow-out type free wall rupture were included in this study. Six patients required mechanical circulatory assist such as IABP (Intra-Aortic Balloon Pumping) and/or V-A bypass before operation. Four patients underwent an emergent operation after establishment of the circulatory assist and two patients had an urgent operation 5 and 10 days after the establishment respectively. Another patient underwent repair of cardiac rupture following manual cardiopulmonary resuscitation. Thus, preoperative mechanical circulatory assist was initiated in seven patients. Eight patients who were not supported by any preoperative mechanical circulatory assist underwent an emergent operation. At operation, infarcted free wall myocardium was resected and repaired with or without a patch, and ventricular septal perforation was repaired with a heterogeneous patch. The seven patients with preoperative mechanical circulatory assist and a patient without it required postoperative mechanical circulatory assist because of intractable heart failure. Six patients with perioperative circulatory assist, however, could not get recovery from their impaired cardiac function, and one died from infective mediastinitis after being weaned from IABP and V-A bypass with PCPS (Percutaneous CardioPulmonary Support). Seven patients who did not have perioperative mechanical circulatory assist uneventfully recovered but one. We concluded that mechanical circulatory assist can give a chance of survival to a patient with far advanced heart failure following ischemic cardiac rupture, and that a prompt and definite diagnosis and a prompt surgical repair are inevitable to get better clinical results.

Aged↗
PubMed1997

[A case of successful treatment of mediastinitis and prosthetic graft infection after aortic arch and thoracoabdominal aortic reconstruction].

Thoracic graft infection is a serious complication with high mortality. We report a case of successful treatment of mediastinitis and graft infection after aortic arch and thoracoabdominal aortic reconstruction. A 56-year-old woman underwent surgery for thoracoabdominal aortic aneurysm. The aneurysm was replaced with prosthetic grafts. She had a high fever on the 12th postoperative day (POD). A Chest X-ray and CT scan demonstrated fluid collection around the grafts. On the 17th POD, mediastinal drainage was performed and Staphylococcus epidermidis was detected. Because of the difficulty to replace the infected grafts, a continuous drainage from the mediastinal cavity around the grafts was induced for 17 days and sensitive antibiotics to the pathogen was administered systemically for 40 days. Inflammatory reactions were improved and her general condition was stabilized. On the 64th POD, she was discharged.

Anti-Bacterial Agents↗
PubMed1997

[Postoperative inflammatory responses to gelatin- and collagen-impregnated Dacron grafts and changes of endotoxin].

Between June, 1993 and January, 1995 a gelatin-sealed knitted Dacron (Gelseal) (g-G0, n = 7) and a collagen-sealed knitted Dacron graft (Hemashield) (g-H0, n = 8) were randomly implanted to 15 patients (pts) for replacement of thoracic aorta. We evaluated postoperative inflammatory responses and levels of Toxicolor and Endospecy which are the measurements of endotoxin. Five pts in g-G0 and 3 pts in g-H0 showed that a body temperature (BT) were above 37.5 degrees C on the 7th postoperative day (POD). In three of them (2 in g-G0 and 1 in g-H0), BT above 37.5 degrees C continued until POD 14 due to the bacterial infection. The other causes of elevation of BT were pleural effusion (2), pericardial effusion (1) and unknown origin (2). Patients without evidence of infection (n = 12) were divided into 2 groups (g-G: pts with Gelseal, n = 5, g-H: pts with Hemashield, n = 7). On POD3, postoperative BT in g-H was significantly higher than in g-G. And, on POD7, BT in g-G rose up more than in g-H. However, on POD14, BT decreased to the normal range in both groups. The values of WBC in g-G were slightly higher than in g-H and they became normal after POD7 in both groups. The levels of CRP in g-H were higher than in g-G after POD3 and in both groups they were still high on POD14. In terms of endotoxin., Toxicolor was already above the normal range from POD1 and decreased to the normal range after POD14. However, the level of Endospecy kept within normal range. In conclusion, Toxicolor-reactive substance elevates by using Gelseal and Hemashield. Its substance is not endotoxin. It would not be appropriate to consider that endotoxin is an origin of fever between POD7 and 14.

Aortic Aneurysm, Thoracic↗