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Biomedical subjects

T Hadama

Publications and source records attributed to T Hadama.

At least 19 recordsLinked to original sources
PubMed1996

Nucleotide sequence diversity of hypervariable region 1 of hepatitis C virus in Japanese hemophiliacs with chronic hepatitis C and patients with chronic posttransfusion hepatitis C.

Hemophiliac patients with chronic hepatitis C might be exposed to and become infected with multiple hepatitis C virus (HCV) strains by means of frequent use of blood products, even if they are infected with a single subtype of HCV. To test this hypothesis, we analyzed the genetic diversity of hypervariable region 1 (HVR1) of HCV in chronically infected hemophiliacs and in patients with chronic posttransfusion hepatitis with a single HCV inoculation. The diversity of nucleotide sequences in HVR1 of serum HCV RNA was compared between 21 hemophiliacs infected with a single HCV subtype and 16 patients with posttransfusion HCV infection. The number of HCV quasispecies was determined by fluorescence single-strand conformation polymorphism (SSCP) analysis. Direct sequencing was performed to determine the diversity in HVR1. The number of HCV quasispecies in the blood was 5.2 +/- 2.0 clones in hemophiliacs and 4.0 +/- 2.3 clones in posttransfusion patients, a nonsignificant difference (P = .0943). The number of sites at which the nucleotide was not homogenous in all quasispecies was significantly higher in hemophiliacs (13.0% +/- 7.4%) than in posttransfusion hepatitis patients (2.7% +/- 2.8%; P < .0001). In conclusion, there was a high degree of genetic variation in HVR1 of HCV specimens isolated from hemophiliacs compared with posttransfusion patients. These findings indicate the possibility that multiple infections of a single HCV subtype may occur among patients frequently exposed to blood products; single HCV subtypes may therefore derive from multiple origins.

Adult↗
PubMed1996

Repair of a ruptured aortic arch aneurysm complicated by postoperative paraplegia: report of a case.

We report herein the rare case of a 79-year-old man who suffered permanent paraplegia after undergoing an otherwise successful total arch replacement for a ruptured aortic arch aneurysm. During cardiopulmonary bypass, perfusion to the distal aorta was maintained from the femoral artery, and postoperative aortography showed intact tributaries from the aorta including the intercostal arteries. Postoperative paraplegia is an extremely rare complication of operations on the aortic arch; however, we speculate that the paraplegia in this patient could be attributed either to a steal phenomenon involving the radicular artery, or to the anatomical particularity of the spinal cord artery described by Cole and Gutelius as the "segmental system".

Aged↗
PubMed1996

[A case of pulmonary dirofilariasis diagnosed through thoracoscopic lung biopsy].

A fifty-year-old man was admitted to our hospital for evaluation of an abnormal shadow in a routine chest X-ray film. Thorax CT scan revealed a relatively well defined nodule with a diameter 15 mm and pleural thickness in the posterior segment of the right lower lobe. A diagnosis by broncoscopy was undefinite and suspected to be a lung cancer. So thoracoscopic lung biopsy was performed to remove it. In a cross section of the resected nodule two degenerated worm structures were revealed and we diagnosed pulmonary dirofilariasis. Pulmonary dirofilariasis has been an increasing reported disease. Most of cases revealed a peripheral lung lesion. Thoracoscopic lung resection was useful for the diagnosis, considering as minimally invasive examination.

Animals↗
PubMed1995

University of Wisconsin solution preserves myocardial calcium current response to isoproterenol in isolated canine ventricular myocytes.

BACKGROUND: University of Wisconsin (UW) solution has been shown to be an effective solution for cold storage of various organs. This study was designed to evaluate the subcellular protective mechanism of UW solution during cardiac myocyte storage using patch-clamp techniques for the first time as a tool for the detection of myocyte viability. METHODS AND RESULTS: The protective effects of UW solution on the preservation of dihydropyridine-sensitive Ca2+ channel current response to catecholamine were evaluated in canine cardiac ventricular cells by measurement of single channel open probability. Single ventricular myocytes were isolated and stored in UW solution, in Stanford (SF) solution, or in St Thomas' (ST) solution at 4 degrees C for 2, 6, 12, and 24 hours, and after each storage period, recordings were made of cell-attached single Ca2+ channel currents. When 0.1 mumol/L isoproterenol was applied, percent mean open probability of the Ca2+ channel tested in freshly isolated cells was 167 +/- 4% (n = 24) of controls (100%). The response was decrescent with increased duration of the hypothermic storage and was only 130 +/- 12% (n = 4) after 24 hours of storage in SF solution and 135 +/- 9% (n = 7) in ST solution. However, it was significantly highly preserved as much as 165 +/- 9% (n = 6) in UW solution. Ca2+ channel kinetics and channel conductance were not changed after up to 24 hours of hypothermic storage. CONCLUSIONS: Hypothermic storage of canine cardiac myocytes in UW solution preserved beta-adrenergic response, which suggests that UW solution during cold storage preserved high-energy phosphates in myocytes that are responsible for Ca2+ channel phosphorylations.

Adenosine↗
PubMed1995

The effect of body position on a free-floating ball thrombus as observed by transesophageal echocardiography.

Two cases of free-floating left atrial ball thrombi (FLABT) in association with mitral stenosis were observed by transesophageal echocardiography (TEE). Our report describes the relation between body position and thrombi kinetics. Both cases demonstrated similar kinetics. In the supine and right lateral decubitus positions, the thrombi recoiled from and sometimes became entrapped within the mitral valve. In the sitting and left lateral decubitus positions, the thrombi appeared to be nearly fixed and did not contact with the mitral valve. Our results indicate that the latter two positions prevent thrombi disintegration and incarceration into the mitral valve. Finally, TEE is an extremely useful tool for assessing the safest position for individuals with FLABT.

Aged↗
PubMed1995

Hemodynamic profiles during concurrent intraaortic balloon pumping and venoarterial bypass--a canine study comparing subclavian and femoral artery perfusion sites.

Concomitant use of venoarterial bypass (VAB) with centrifugal pump and intraaortic balloon pumping (IABP) is a common technique for cardiopulmonary resuscitation. This experimental study examines whether coronary perfusion and hemodynamics are affected by the site of the blood supply, comparing the subclavian artery and the femoral artery. VAB and IABP were performed in 11 mongrel dogs with cardiopulmonary failure induced by acute myocardial infarction and hypoventilation. Aortic root pressure (AP), left atrial pressure, central venous pressure and coronary sinus blood flow (CSF) were measured, and blood gas analysis was performed. Subclavian artery perfusion (SAP) and femoral artery perfusion (FAP) were compared at bypass ratios of 25, 50, 75, 85, 100%. At bypass ratios of 75% and 85% the mean systolic AP was higher with SAP than with FAP. The mean diastolic AP was higher with SAP than with FAP at a bypass ratio of 50% or higher. CSF was higher with SAP than with FAP at a bypass ratio of 50% or higher. The coronary arteriovenous O2 content difference was lower with SAP than with FAP at a bypass ratio of 85% or higher. In conclusion, at a high bypass ratio, SAP was more effective than FAP in achieving diastolic augmentation, thus enhancing myocardial oxygen balance, even though SAP had less of a systolic unloading effect. These data support the use of SAP over FAP in patients with severe cardiopulmonary dysfunction requiring high-flow bypass, and especially in patients with myocardial ischemia.

Animals↗
PubMed1995

[Factors affecting the occurrence of anastomotic leakage after graft replacement of type A aortic dissection].

Fifty-seven patients of type A aortic dissection were underwent operations from Jan. 1985 to Nov. 1994. The number of patients who underwent graft replacement of the aorta and received aortogram after the operation was twenty-nine. To investigate factors affecting the occurrence of anastomotic leakage after graft replacement of the aorta, the aortograms of the 29 patients were examined retrospectively. The aortograms revealed leakage at the distal anastomotic site on 11 of the 29 patients. Eight factors: the kind of graft, Marfan's syndrome, the use of felt at the anastomotic site, the clamping method, distal anastomotic site, acute or chronic, the state of the aortic wall at the anastomotic site and the blood pressure control after operation, were examined relating to the occurrence of anastomotic leakage. The results showed 3 factors; acute or chronic, the state of the aortic wall and the blood pressure control, affected the occurrence of anastomotic leakage. In short, the anastomotic leakage easily occurred in patients who underwent in the acute stage and whose blood pressure was uncontrolled after the operation. Therefore, strict control of the blood pressure after the operation is the most effective for preventing anastomotic leakage.

Anastomosis, Surgical↗
PubMed1995

[Surgical treatment of traumatic rupture of the aortic valve with dove-coo murmur--case report].

Aortic regurgitation due to traumatic rupture of the aortic valve with dove-coo murmur is rare. A 71-year-old man was admitted for cardiac failure due to aortic regurgitation with dove-coo murmur, 4 years after the traffic accident. The aortic valve replacement was performed and his postoperative course was good. The aortic valve was tricuspid valve with the tear in the left side of right coronary cusp, and the size of the tear was 7 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic change in the pathological study.

Aged↗
PubMed1995

[Surgical treatment of right atrial papillary fibroelastoma, originated from the eustachian valve--a case report].

Papillary fibroelastoma is one of the most common benign primary cardiac tumor after myxoma. However, it is rare to originate from Eustachian valve. A 44-year-old woman was pointed out the right atrial tumor during admission for vasospastic angina. On two-dimensional echocardiogram, the tumor was found in the right atrium, and easily moved to the right ventricle. At operation, the tumor originated from Eustachian valve, and was resected together with the valve by means of extracorporeal circulation. The size of tumor was 57 mm in length, and the histological diagnosis was papillary fibroleastoma. The post-operative course was uneventful.

Adult↗
PubMed1994

Biocompatibility of a heparin-bonded membrane oxygenator (Carmeda MAXIMA) during the first 90 minutes of cardiopulmonary bypass: clinical comparison with the conventional system.

We clinically compared a heparin-bonded Carmeda MAXIMA membrane oxygenator to a nonheparin-bonded MAXIMA in 20 patients undergoing coronary artery bypass grafting or valve replacement. Reductions of fibrinogen, factor XII, and high molecular weight kininogen were greater in the MAXIMA group. Serum C3a and free hemoglobin were lower in the Carmeda group. The level of C4a, though remarkably lower than that of C3a, was higher in the Carmeda group then in the MAXIMA group. Both oxygenators performed well in terms of blood gas exchange. We conclude that the heparin-bonded Carmeda oxygenator offers superior biocompatibility during cardiopulmonary bypass.

Biocompatible Materials↗
PubMed1994

[Effect of pirenzepine on gastric mucosal blood flow in patients after cardiac surgery].

Effect of pirenzepine on gastric mucosal blood flow (GMBF) in adult patients after coronary artery bypass grafting and mitral and aortic valve replacement was evaluated by using endoscopic laser-Doppler velocimetry. Heart rate, blood pressure and cardiac output increased temporarily after intravenous administration of pirenzepine 20 mg. GMBF also increased with these hemodynamic changes. However, GMBF remained significantly higher even after the decrease of cardiac output. Therefore, the increase in GMBF, which might be due in part to increase in cardiac output, could be explained by pirenzepine's own effect on gastric mucosa. Since the GMBF is one of the most important gastric mucosal defensive factors, pirenzepine may be useful in preventing acute gastric mucosal lesions in patients with low cardiac output.

Aged↗
PubMed1994

[A case of rupture of the ascending aorta owing to prosthetic graft dilation following replacement of the descending aorta].

A 55-year-old male was diagnosed as acute type A aortic dissection caused by retrograde propagation from a tear in the descending aorta. A replacement of the descending aorta was performed with a prosthetic graft (VASCUTEK). Sixteen days after the operation, the patient required an emergency operation due to a rupture in the ascending aorta. Transesophageal echo and contrast enhanced CT indicated the point of entry to be at the proximal anastomotic portion of the prosthetic graft and the prosthetic graft (30 mm in diameter) to be dilated to 45 mm. Intimal tear at anastomotic portion owing to graft dilation was suspected as the main factor causing rupture of the ascending aorta.

Aortic Dissection↗
PubMed1994

[Two cases of aortoesophageal fistula due to ruptured thoracic aortic aneurysm].

Aortoesophageal fistula due to ruptured thoracic aortic aneurysm is uncommon, and exhibits extremely high mortality. We experienced two cases of such lesion. The first case showed aneurysm in the aortic arch closed with Dacron patch but leaving the esophageal defect. The patient died of an infection of the patch graft after oral feeding. The second case was demonstrated infected aneurysm of the descending aorta. The patient was rescued by primary operation, replacement of the aorta by an artificial graft and resection of the esophagus, and the secondary operation, reconstruction of the esophagus. We recommend resection of aneurysm and the esophagus as well in the aspect of lower post-operative infection in the graft and of the better prognosis of the lesion.

Aged↗
PubMed1993

Intracellular Na+ activity of "diseased" human atrial muscles and its modifications by dihydro-ouabain.

In quiescent human atrial muscles obtained from patients with various cardiac diseases, the intracellular Na+ activity (aNai) and the resting membrane potential (Vm) were recorded simultaneously, using double-barreled Na(+)-selective microelectrodes. The Vm averaged -44.1 +/- 5.0 mV and the aNai, 6.9 +/- 1.7 mM under normal Tyrode's solution containing 5.4 mM [K]oi,The aiNa value was within the range of aNai reported in various cardiac tissues from intact animals. Dihydro-ouabain (10(-5) M) significantly increased the aNai and depolarized the Vm. The results suggest that even in these depolarized atrial muscles the aNai remains within physiologic levels and that the Na-K pump may not be impaired. This is the first report to measure the aNai in human atrial muscles.

Adolescent↗
PubMed1993

[Clinical experience of VA-bypass as a cardiac assist system using centrifugal pump with membranous oxygenator in patients with profound ventricular failure after cardiac surgery].

Twelve patients including 6 ischemic heart diseases, 5 valvular diseases, and one adult atrial septal defect combined with mitral and tricuspid valve insufficiency were treated with circulatory assist system for postoperative severe low-cardiac output syndrome. Intra-aortic balloon pumping (IABP) was used in all cases. In early 7 cases, left heart bypass system was employed including one roller pump, one left ventricular assist device (LVAD), and 5 centrifugal pump. Only one LVAD case could be weaned but died of sustained ventricular arrhythmias 5 days postoperatively. In recent 5 cases, veno-arterial bypass (VA-bypass) was employed using centrifugal pump with membranous oxygenator. Venous blood was drained from the right atrium and oxygenated blood was returned to the right axillary artery. Real time reinfusion of drained blood from intrapericardial and mediastinal tube to the central vein served efficiently to maintain hemodynamics and to save homologous blood transfusion. Three of 5 cases who were treated with Va-bypass survived and are doing well. We conclude that VA-bypass consisting with centrifugal pump and oxygenator returning oxygenated blood to the right axillary artery combined with IABP were useful strategies as biventricular support for profound cardiac failure following surgery.

Aged↗
PubMed1993

[Surgical treatment of endocardial cushion defect in 3 elderly patients].

We performed surgical treatment for partial endocardial cushion defect in 3 patients over fifty year old. Case 1 was a 55-year-old-male with TR of grade II. Case 2 was a 59-year-old-female with TR and MR, and was repaired mitral cleft by a mattress suture. She needed infusion of dopamine (over 5 micrograms/kg/min) for 6 days and therapy of mediastinitis postoperatively. Case 3 was 56-year-old-male without atrioventricular valve regurgitation. Preoperative left ventricular volume was small in all patients, therefore perioperative circulatory control, mainly water balance, and respiratory control were importance. All patients survived, and both decreasing of CTR and improvement of NYHA classification were recognized in all three patients. In conclusion the operation for ECD in even elder patients was effective, but intensive care needed perioperatively.

Endocardial Cushion Defects↗
PubMed1993

[A case of double mitral valve with severe mitral regurgitation detected by transesophageal echocardiography].

A 66-year-old woman with double mitral valve (bridge type) and severe mitral regurgitation by spontaneous ruptured chordas is reported. The case with this combination has not been reported in the literature. She had not any other congenital heart diseases. The mitral valve was clearly shown by two-dimensional Doppler transesophageal echocardiography. Mitral valve replacement with Medtronic-Hall valve was carried out successfully.

Aged↗