Biomedical subjects

S Kuki

Publications and source records attributed to S Kuki.

At least 19 recordsLinked to original sources

PubMed2000

Left ventricular myocardial remodeling and contractile state in chronic aortic regurgitation.

BACKGROUND: In chronic aortic regurgitation, eccentric hypertrophy, with combined concentric hypertrophy of the left ventricle, is an important adaptive response to volume overload, which in itself is a compensatory mechanism for permitting the ventricle to normalize its afterload and to maintain normal ejection performance (physiologic hypertrophy). However, progressive dilatation of the left ventricle leads to depressed left ventricular (LV) contractility and myocardial structural changes, including cellular hypertrophy and interstitial fibrosis (pathological hypertrophy). HYPOTHESIS: The study was undertaken to determine the relationship between left ventricular myocardial structure and contractile function in 14 patients with chronic aortic regurgitation by cardiac catheterization and endomyocardial biopsies. METHODS: Myocardial cell diameter and percent interstitial fibrosis were obtained from biopsy samples. Contractile function was evaluated from the ratio of end-systolic wall stress to end-systolic volume index (ESS/ESVI) and the ejection fraction-end-systolic stress (EF-ESS) relationship, which was obtained from 30 normal control subjects. RESULTS: Myocardial cell diameter correlated significantly with the ESVI (r = 0.72, p < 0.005), ejection fraction (r = -0.58, p < 0.05), and ESS/ESVI (r = -0.58, p < 0.05). The percent interstitial fibrosis also correlated inversely with ESS/ESVI (r = -0.71, p < 0.005). Compared with very few patients with an ESVI < 70 ml/m2, the majority of patients with ESVI > or = 70 ml/m2 had a cell diameter of > or = 30 microns and a percent interstitial fibrosis of > or = 10%. The nine patients who had depressed contractile function, as assessed from the EF-ESS relationship, had a higher percent interstitial fibrosis (p < 0.05) than five patients showing a normal EF-ESS relationship, despite the fact that there was no significant difference in myocardial cell diameter between them. Thus, advanced cellular hypertrophy and excessive interstitial fibrosis were significantly and independently associated with myocardial contractile dysfunction and appeared to be responsible for ventricular remodeling. CONCLUSION: Our findings suggest that in many patients with aortic regurgitation, eccentric hypertrophy changes its nature from physiologic to nonphysiologic during the earlier stages in the course of the disease rather than during the stage described previously.

Adolescent↗

PubMed2000

Dissecting thoracoabdominal aortic aneurysm associated with an isolated right-sided aortic arch.

Although a right-sided aortic arch is not a rare anomaly, an aortic dissection involving an isolated right-sided aortic arch is extremely rare and remains a complicated entity for surgical therapy because of its anatomical characteristics. Previous reports that we have identified in English literature include only six surgical cases of aortic dissection involving a right-sided aortic arch. We report on a 75-year-old female who had a chronic thoracoabdominal aortic aneurysm following type B aortic dissection in a right-sided aortic arch. Graft replacement including reconstruction of Adamkiewicz artery and a celiac trunk was performed. The postoperative course was uneventful except for a prolonged ventilatory support. This case seems to be the first successful case of extended graft replacement for this pathology.

Aged↗

PubMed2000

A novel modification of elephant trunk technique using a single four-branched arch graft for extensive thoracic aortic aneurysm.

Surgical repair for the extensive thoracic aortic aneurysm remains unsatisfactory, especially in elderly patients. We developed a total arch replacement with modified elephant trunk technique under moderately hypothermic cardiopulmonary bypass and selective brain perfusion, in which a 4-branched arch graft with a sewing 'collar' enabled the distal anastomosis just proximal to the innominate artery with open distal method and a long 'elephant trunk' was inserted into the descending aorta by the forceps catheter via the femoral artery. This modification is easy and less invasive, and reduces the risk of postoperative complications.

Aged↗

PubMed2000

Multiple mycotic arch-thoraco-abdominal aortic aneurysms: a successful case of in situ graft replacement.

Mycotic aortic aneurysms are an uncommon yet still life-threatening pathology. We report on a 67-year-old male who had a persistent fever and back pain. Contrast enhanced computed tomography (CT) showed multiple aortic aneurysms located in the aortic arch, the descending thoracic aorta and the supraceliac abdominal aorta. After 2 months of antibiotic therapy, a staged operation was carried out with 2-week interval, which includes a graft replacement of aortic arch with elephant trunk technique and a graft replacement of thoraco-abdominal aorta with omental transfer. The postoperative course was uneventful. This case seems to be quite rare in terms of multiplicity and location of mycotic aneurysms. Surgical strategy for this pathology is discussed.

Aged↗

PubMed1998

Upregulated and downregulated transcription of myocardial genes after pulmonary artery banding in pigs.

BACKGROUND: Acute or chronic pressure overload may occur during or after cardiac surgical procedures. Typical examples are aortic cross-clamping and pulmonary artery banding. It is well known that mechanical stress induces transcription of different myocardial genes. However, these results were mainly obtained from in vitro studies and experiments with rodents. This experiment was carried out to investigate molecular alterations after pressure overload in porcine hearts. METHODS: The study was performed with 35 Landrace pigs with a mean weight of 32+/-1.2 kg. The five groups consisted of 7 pigs each, 3 sham-operated pigs and 4 banded pigs. The hearts were exised after different time intervals. We investigated messenger RNA expression of sarcoplasmic reticulum adenosine triphosphatase, phospholamban, alpha-/beta-myosin heavy chain, and atrial natriuretic factor by Northern blot analysis. RESULTS: The ratio of right ventricular weight to body weight increased significantly after 7 and 24 days in banded pigs (p < 0.05). Atrial natriuretic factor messenger RNA was significantly upregulated in banded pigs versus sham-operated pigs after 1 day (240%+/-7% versus 100%+/-6%; p < 0.01) and 3 days (520%+/-8% versus 100%+/-8%; p < 0.01). There was insignificant downregulation of sarcoplasmic reticulum adenosine triphosphatase and phospholamban after 1, 3, and 7 days. Myosin heavy chain messenger RNA expression remained unchanged. CONCLUSIONS: Pulmonary artery banding results in hypertrophic response of the porcine right ventricle; however, the weight increase is not the result of myosin heavy chain messenger RNA upregulation. Atrial natriuretic factor messenger RNA is locally expressed in mechanically stressed myocytes. Furthermore, pressure overload downregulates transcription of calcium-binding proteins that can influence ventricular contractility. These results may have an impact on cardiac surgical procedures.

Adenosine Triphosphate↗

PubMed1997

Increased growth factor transcription after pulmonary artery banding.

OBJECTIVE: Several mechanisms are known to produce mechanical stress during and after cardiac surgery, e.g. aortic cross-clamping and pulmonary artery banding (PAB). However, little is known about the transcription of myocardial genes which are changed during mechanical overload. This study was performed to investigate growth factor mRNA expression after PAB in porcine hearts. METHODS: The experiment was performed in 35 pigs (five groups). Each group consisted of three sham-pigs (S-pigs) and four banding-pigs (B-pigs). The mean transbanding gradient in B-pigs was 29 +/- 2.5 mm Hg. The hearts were excised after different time intervals. The probes were snap-frozen in liquid nitrogen and stored at -80 degrees C. Analysis was performed by Northern blot. RESULTS: Right ventricular weight increased significantly after 7 and 24 days (P < 0.05). There was an upregulation of transcriptional and growth factors in B-pigs: c-jun mRNA: 412 +/- 12.1% after 2 h (P < 0.001); c-fos mRNA: 303 +/- 18.5% after 2 h (P < 0.001); vascular endothelial growth factor (VEGF) mRNA: 203 +/- 18.2% after 2 h (P < 0.001); Flk-1 mRNA: 156 +/- 16% after 2 h (P < 0.05), 253 +/- 5% after 24 h (P < 0.01) and 184 +/- 12% after 3 days (P < 0.01); transforming growth factor-beta1 (TGF-beta1) mRNA: 255 +/- 21.5% after 24 h (P < 0.002). Fibroblast growth factors 1 and 2 (FGF-1 and FGF-2) were constitutively expressed in B- and S-pigs and did not change their expression. CONCLUSIONS: Pulmonary artery banding results in significant right ventricular hypertrophy and upregulation of different growth factors. However, growth factors known to induce hypertrophy in vitro, like the FGFs, showed unchanged expression. We think that myocardial growth factors may have trophic functions in the heart which may be useful for cardiac surgery in future.

Animals↗

PubMed1995

Acute Budd-Chiari syndrome due to inferior vena cava occlusion following blunt trauma.

Inferior vena cava (IVC) thrombosis or obstruction is a complication rarely associated with blunt trauma. We present a case of IVC thrombo-occlusive lesion with both hepatic and renal failure which developed after a thoracoabdominal blunt trauma. Direct thrombectomy and patch cavoplasty were successfully carried out under deep hypothermia using cardiopulmonary bypass.

Acute Disease↗

PubMed1994

Multichannel myocardial temperature probe.

We present a new system to measure myocardial temperature at multiple points in myocardium. This system consists of a probe with multiple thermocouples, a data collector, and a personal computer. We have demonstrated a change in distribution of temperature in myocardium during hypothermic cardioplegic arrest.

Bias↗

PubMed1994

Successful surgical management for multiple cerebral mycotic aneurysms involving both carotid and vertebrobasilar systems in active infective endocarditis.

Mycotic aneurysm is usually found in the middle cerebral artery associated with infective endocarditis. Previous reports we have identified include only 4 cases of vertebrobasilar aneurysm. We report on a 29-year-old female who had multiple mycotic aneurysms involving both the carotid and vertebrobasilar systems complicated by intracranial hemorrhage with infective endocarditis, in whom staged operations, mitral valve replacement and craniotomies, were successfully performed.

Adult↗

PubMed1994

[A successful case of transaortic coronary patch angioplasty for left coronary ostial stenosis in a middle-aged woman].

A 46-year-old woman was admitted to our hospital because of effort angina. Electrocardiogram on exercise showed a significant ST depression in I, II, III, aVF, and V3-6 201Thallium myocardial scintigram demonstrated a low uptake lesion on effort and redistribution in anterior wall of left ventricle. Coronary angiography showed a 50% stenosis only in the left coronary ostium. Operation was carried out by transaortic patch angioplasty using autologous pericardium fixed with 0.25% glutaraldehyde. Her postoperative course was uneventful. Anginal discomfort disappeared, and favorable results was obtained. Recent reports suggest that an isolated coronary ostial stenosis is a distinct clinical entity which is different from the usual atherosclerotic ischemic heart disease. The transaortic patch angioplasty might be useful operative method for the isolated coronary ostial stenosis.

Constriction, Pathologic↗

PubMed1994

[An experience of successful valve repair for acquired mitral and tricuspid regurgitation in dextrocardia, situs inversus, bilateral vena cava, and hemiazygos continuation].

A 56-year-old woman was admitted to our department because of congestive heart failure. Chest X-ray showed dextrocardia with situs inversus. The echocardiography revealed severe mitral regurgitation due to prolapse of posterior leaflet and secondary Venography demonstrated the bilateral superior vena cava, huge coronary sinus and hemiazygos continuation with hypoplastic inferior vena cava. Mitral valve regurgitation was repaired by Carpentier's and Burr's technique, and tricuspid valve regurgitation was repaired by Kay's technique. Her postoperative course was uneventful. Valve surgery for acquired valvular lesion in dextrocardia with situs inversus is rare. Although valve repair is easily performed even in mirror-image heart as well as in normal, levo-position heart, preoperative evaluation of systemic venous return is important in the case of dextrocardia with systemic venous anomalies.

Azygos Vein↗

PubMed1994

[A case of coronary artery bypass grafting for single coronary artery complicated by effort angina].

A case of coronary artery bypass grafting (CABG) for single coronary artery (SCA) complicated by effort angina pectoris was reported. A 52-year-old man was admitted complaining of effort angina. Coronary arteriography demonstrated a single coronary artery originated in left coronary sinus bifurcated to the left anterior descending artery (LAD) and the circumflex artery (CX) which extended around the atrio-ventricular fold to send a branch down the posterior small branches extend to posterior surface of the right ventricle. This type single coronary artery was classified to Smith's type I. Other findings included 75% stenosis in LAD #6 and #7, 90% stenosis in CX #11. CABG was carried out using left internal thoracic artery graft and saphenous vein graft. His postoperative course was uneventful. Anginal discomfort disappeared, and favorable results was obtained. SCA might be vulnerable to ischemic insult, so that coronary revascularization should be recommended in selected cases before the onset of serious complications.

Angina Pectoris↗

PubMed1994

[A successful case of left heart bypass with biocompatible bypass circuit and minimal heparin for severe heart failure after open mitral commissurotomy].

A successful case of left heart bypass (LHB) for severe heart failure after mitral commissurotomy is presented. A 44-year-old woman underwent surgery for mitral and tricuspid regurgitation, then could not be weaned from cardiopulmonary bypass because of low cardiac output and intractable ventricular arrhythmia. The LHB from right-sided left atrium to ascending aorta was instituted with anti-thrombogenic centrifugal pump system (Carmeda). During initial 6 hours of LHB, any anticoagulant drugs were not employed, thereafter the local administration of heparin into left ventricle was started with a dose of 200 unit per hour. The LHB was successfully weaned at 26 hours after institution. Her postoperative course was uneventful. The left heart bypass without systemic heparinization utilizing anti-thrombogenic material might be a safe and useful method for postcardiotomy cardiogenic shock.

Adult↗

PubMed1994

[A left atrial appendage thrombus without mitral stenosis--a successful case of removal].

Successful thrombectomy for left atrial ball thrombus without mitral stenosis is presented. A 62-year-old man was admitted to our department because of intermittent claudication. Arteriography demonstrated complete occlusion in bilateral superficial femoral arteries, however, the arterial wall was much smooth, suggesting thrombo-embolism rather than arteriosclerosis obliterans. The transthoracic echocardiography revealed no abnormal lesion in mitral apparatus and in left atrial cavity. The bypass operation was carried out for arterial occlusion, when the intraoperative transesophageal echocardiography showed the ball thrombus in left atrial appendage. The urgent operation was successfully carried out on 14th postoperative day after bypass operation. The thrombus occupied almost all the left atrial appendage, and its size was 24 x 19 x 13 mm. The transesophageal echocardiography was useful in diagnosis for left atrial appendage thrombus. Once the diagnosis was made for large and movable left atrial thrombus, immediate surgical therapy should be recommended to avoid serious complications and sudden death.

Echocardiography, Transesophageal↗

PubMed1994

[A successful case of valve-sparing surgery for tricuspid valve endocarditis].

A successful repair for infective endocarditis of the tricuspid valve is presented. A 35-year-old man was referred to our hospital complaining of high fever despite antibiotic chemotherapy. Lung scan showed multiple thromboembolism. Blood cultures revealed staphylococcus aureus. Echocardiography showed vegetations attached to the tricuspid valve and severe tricuspid regurgitation. Conservative surgery such as vegetectomy and DeVega's annuloplasty was successfully carried out. The patient's postoperative course was uneventful. The conservative surgery might provide a satisfactory result in the selected cases with localized vegetation and minimum valve involvement.

Adult↗

PubMed1993

[A case of impending rupture of acute aortic dissection with thrombosed false lumen in early phase].

A 73-year-old patient with acute aortic dissection in delayed shock state following sudden onset of chest-back pain and left sided hemothorax was successfully operated. Contrast enhanced CT demonstrated a crescent-shaped low density area in the descending aorta. Aortography showed ulcer-like projection (ULP) with minor leakage into left thorax, however, a flow in false lumen was not visualized. These findings suggested that the false lumen of type III aortic dissection was thrombosed in its early phase. The aneurysm was transected on left heart bypass through left thoracotomy. The entry of false lumen was found in proximal portion of descending aorta, in which fresh thrombus was filled. A graft was anastomosed and reinforced with felt strips in end-to-end. The postoperative course was uneventful. The ULP by aortography provides a possible sign of rupture in clinical course of aortic dissection.

Aged↗

PubMed1991

[A successful case of concomitant operation for coronary artery disease and rectal cancer in elderly patient].

We report a successful case of 75-year-old man who was simultaneously undertaken CABG for coronary artery disease and Miles' operation for rectal cancer. A concomitant cardiac and rectal operation involves serious problems, such as increasing operative risk, bleeding tendency after cardiopulmonary bypass, infection and radicality against malignancy, however, it should be a definitive method for the selective case.

Adenocarcinoma↗

PubMed1990

NMR characteristics of intracellular K in the rat salivary gland: a 39K NMR study using double-quantum filtering.

Intracellular K of the perfused rat mandibular salivary gland was measured by 39K NMR spectroscopy at 8.45 T. Multiple-quantum NMR arising from multiple-exponential decay was used to eliminate the resonance due to extracellular K in the perfused gland at 25 degrees C. The resonance due to intracellular K consisted of two Lorentzian signals stemming from the [spin 1/2 to -1/2] coherence (sharp resonance) and the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences (broad resonance). The transverse relaxation time (T2) corresponding to the [spin 1/2 to -1/2] coherence was ca. 2.5 ms, and that corresponding to the [spin -1/2 to -3/2], [spin 3/2 to 1/2] coherences was ca. 0.4 ms. The relaxation time of the double-quantum coherence of rank 3 (originating from product operators like Ix2Iz) was determined to be ca. 0.2 ms. These results suggest the possibility of the presence of a single homogeneous population of intracellular K with a correlation time of ca. 2.5 x 10(-8) s and a quadrupolar coupling constant of ca. 1.4 MHz.

Animals↗