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Biomedical subjects

K Yagyu

Publications and source records attributed to K Yagyu.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Anticoagulation therapy after mechanical prosthetic heart valve replacement with special reference to international normalized ratio (INR)].

We compared the efficacy and complications of anticoagulation with warfarin in 98 patients after isolated mitral valve replacement (MVR 57 pts) and isolated aortic valve replacement (AVR 41 pts). Fifty Medtronic-Hall valves, 33 St. Jude Medical valves, 9 Björg-Shiley valves and 6 other valves were used. In 1991, we made our control standard of prothrombin-time (%) between 25% and 35% (INR 2.3-3.1) and in 1992, between 30% and 40% (INR 2.1-2.8), although INR recommended by ACCP in 1988 was 3 to 4.5. In 1991, mean PT (%) was 31.2% and mean INR was 2.75 in our patients. In 1992, mean PT (%) was 35.0% and mean INR was 2.53. In 1991, we experienced bleeding episodes in three patients and thromboembolism in one case. In 1992, no complication occurred. We conclude that anticoagulant therapy of mean INR 2.53 seemed to be more suitable for Japanese patients than the ACCP standard.

Aged↗
PubMed1994

[Pulmonary root reconstruction with a cryopreserved pulmonary allograft for mechanical pulmonary valve thrombosis].

A 58-year-old woman suffering from congestive heart failure caused by a mechanical pulmonary valve thrombosis was operated on with a pulmonary allograft. She had experienced pulmonary valvotomy and resection of infundibular stenotic muscle for congenital pulmonary stenosis at the age of 23 years old. She got congestive heart failure caused by pulmonary regurgitation, and underwent pulmonary valve replacement with a St. Jude Medical (SJM) valve when she was 48 years old. She suffered from episodes of a thrombosed SJM valve in 1984 and 1993. Each time, thrombolytic treatment with urokinase or recombinant tissue-type plasminogen activator was effective. She suffered from the third episode of SJM valve thrombosis in January 1994. As thrombolytic treatment was not effective this time, the thrombosed SJM valve was resected and her pulmonary root was reconstructed with a cryopreserved pulmonary allograft. Postoperative course was uneventful, and she now enjoys her life without anticoagulant therapy.

Cryopreservation↗
PubMed1994

[Thoracoscopic resection of schwannoma: a report of two cases].

We have performed thoracoscopic resection of schwannoma without intraspinal extension in two asymptomatic cases confirmed by chest roentgenogram and computed tomography: the case 1 with the tumor as large as 4.0 x 4.0 x 3.5 cm found in the paravertebral fifth Intercostal space, the case 2 with the tumor as large as 3.2 x 2.5 x 1.8 cm found on the first rib in contact with the supreme intercostal vein. In the operation of case 1, the dilated fifth intercostal vein in contact with the tumor which could not be controlled by Endo-Clip was doubly ligated by the use of Knot-Pusher. The tumor was successfully dissected from the chest wall and proved to arise from the fifth intercostal nerve. The tumor was brought into Endo-Pouch and extracted through one of the skin incisions which was minimally enlarged to accommodate the pouched lesion. In the operation of case 2, curved forceps facilitated the procedure because the tumor located near the apex of thorax. The tumor was found to originate from sympathetic nerve and removed through the minimally enlarged incision as case 1. We conclude as the following. The benign tumor found in the mediastinum or the chest wall is amenable to thoracoscopic treatment. In thoracoscopic procedure, as the operation under thoracotomy, we must acquire skills of standard operative technique, i.e., suture or ligation, because those skills are necessary when Endo-Clip or Endo-GIA cannot be used. The skin incision should be minimally enlarged finally when the specimen is extracted to minimize operative intervention.

Adult↗
PubMed1994

[Hypothermic cardiopulmonary bypass with circulatory arrest of the lower half of the body and selective perfusion of the upper and lower half of the body for thoracic aortic aneurysm operation].

A 62-year-old man with thoracoabdominal aortic aneurysm of Crawford type IA and a 61-year-old woman with triple descending thoracic aortic aneurysms were operated on under total cardiopulmonary bypass with hypothermic circulatory arrest of the lower half of the body (rectal temperature of 17-19 C) and low flow selective perfusion of the upper and lower half of the body. Low porosity woven Dacron UBE grafts without preclotting were used for the replacement of the aorta. Postoperative courses were uneventful without paraplegia and angiographic examination revealed excellent hemodynamic results.

Aortic Aneurysm, Thoracic↗
PubMed1994

[Usefulness of mixed venous oxygen saturation as a monitor of hemodynamic state during pulmonary resection].

We studied the relation between SVO2 and other hemodynamic parameter during lung resection in 28 patients. SVO2, SaO2, CI, Hb and VO2 were measured using a fiberoptic pulmonary artery catheter. SaO2 decreased significantly after collapse of a nondependent lung because of shunt effect, whereas SVO2 remained stable. VO2 and CI increased remarkably and SVO2 decreased gradually after restoration of two lung ventilation suggesting imbalance of auto-regulatory mechanism. SVO2 remained significantly low after extubation in patients whose blood loss of more than 1,000 ml was replaced by stored blood transfusion. We think that the constant number 1.38 in Fick equation should be reset below 1.38 according to the volume of transfused blood, if blood loss was replaced by stored blood.

Adult↗
PubMed1993

Swelling-induced O2- generation in guinea-pig neutrophils.

Without the addition of any exogenous stimuli, neutrophils generated O2- and then ceased in a reversible manner that correlated with cellular swelling and contraction. The nature of the possible mechanism responsible for this O2- generation was studied and compared with that observed in the triggering of stimulant-dependent O2- generation (respiratory burst). The swelling-induced O2- generation was inhibited by diphenyliodonium, and was independent of the functional distortion of mitochondrial and/or microsomal electron transport and xanthine oxidase. This suggested that such generation was involved in respiratory-burst oxidase activation; however, this generation was not accompanied by any new phosphorylation of the 47-kDa protein or of tyrosine proteins. Dihydrocytochalasin B potentiated the O2- generation. The cellular swelling produced a priming effect on the triggering of respiratory burst with different stimuli. Cellular contraction, conversely, suppressed the respiratory burst. The structural specificity of the swelling-induced plasma membrane modulation for the O2- generation was suggested by the finding that modulation of plasma membrane structures by various non-ionic detergents per se inhibited O2- generation. Lipophilic and positively-charged agents inhibited the generation and this inhibition was abrogated by negatively-charged, but not by non-ionic agents. Negatively-charged agents potentiated the O2- generation. These results suggest that both the interaction of the plasma membrane with the cytoskeleton and an increase in net negative charges at the plasma membrane play important role in evoking O2- generation; this is discussed and compared with the signal transduction reported previously for respiratory burst.

Animals↗
PubMed1993

Retrograde gastric varices in a patient with total cavopulmonary shunt.

Gastric varices formed in a patient who had undergone a total cavopulmonary shunt operation 7 years previously. The varices were found to be due to development of collaterals from high-pressure systemic vein to low-pressure portal vein. Bleeding gastric varix can be a late complication of total cavopulmonary shunt.

Arteriovenous Shunt, Surgical↗
PubMed1993

[A role of valvuloplasty in surgical treatment of isolated tricuspid regurgitation].

Seven surgical cases of isolated tricuspid regurgitation were reviewed. From pathological point of view, the patients were classified into three groups. Two were due to abnormalities of subvalvular system, four to annular dilatation and one to anomalous leaflet. Among four cases of annular dilatation, two were diagnosed as dilated cardiomyopathy. In one, it was very rare myopathy confined to right ventricle. Three cases, two subvalvular and one leaflet abnormalities, underwent valvuloplasty which included chordal reconstruction using Gore-Tex suture. Among annular dilatation group, three underwent valve replacement (two with mechanical valve and one with bioprosthetic valve), while fourth underwent annuloplasty. When We look at 89 surgical patients with secondary tricuspid regurgitation, thrombosed mechanical valve was seen in two cases, one of them necessitating re-valve replacement. On the other hand, late results of tricuspid annuloplasty with Carpentier-Edwards ring was excellent without re-operation. Although isolated tricuspid regurgitation has very complicated pathological features, we now think it very important to manage to repair regurgitant tricuspid valve utilizing all available techniques including redundant valve tissue resection, chordal reconstruction, and annuloplasty, thus avoiding valve replacement especially with mechanical valve.

Adolescent↗
PubMed1993

[Curative surgery for lung cancer invading the aorta with bilateral emphysematous giant bullae: a case report].

A 56-year-old male patient who had been suffered from giant emphysematous bullae in both lungs was referred to our hospital because of newly developing left lung abnormal shadow, which was adjacent to the aorta on chest X-ray. Lung cancer invading the aorta was suspected on CT scanning and curative operation was scheduled. At left thoracotomy there were large bullae in the upper lobe, part of which covered on and stuck to the tumor mass on the aortic wall. We performed left upper lobectomy, combined with the partial resection of the aortic wall and repaired it with dacron patch using partial extracorporeal circulation with cannulations into the main pulmonary artery and the descending aorta. Pathological diagnosis was large cell carcinoma. Lung cancer invading the aorta can be safely excised using assisting circulatory devices such as extracorporeal circulation. We expect this type of operation will be widely accepted and make better results.

Aorta↗
PubMed1992

[Analysis of mononuclear cell subpopulations in bronchoalveolar lavage fluid in acute rejection after lung transplantation in rats].

Changes of components of mononuclear cell subpopulations in bronchoalveolar lavage (BAL) fluid were analyzed during acute rejection after lung transplantation in an inbred rat model. All allotransplants (BN/LEW) developed progressive acute rejection from day two until day six, demonstrating severe perivascular and peribronchiolar infiltration of mononuclear cell subpopulations. The number of total cells and activated macrophages increased significantly in BAL fluid from vascular phase until alveolar phase of acute rejection. The number of T and B lymphocytes in BAL fluid increased in alveolar phase, but not in vascular phase of acute rejection. The increase of the number of activated macrophages in BAL fluid may be useful as a monitor of acute allograft rejection following lung transplantation.

Animals↗
PubMed1992

[Congenital bicuspid aortic valve: stenotic type and insufficient type].

Two-hundred and eighty-one patients underwent surgical treatment of the aortic valves during a 10-year period of 1981 to 1991, 32 of whom (11%) had bicuspid aortic valve. Bicuspid aortic valve is well known to cause calcified aortic stenosis, however, some of these cases develop pure aortic insufficiency of unknown etiology. In our studies of 32 patients with bicuspid aortic valve, 28 patients had aortic stenosis, 2 were aortic insufficiency and 2 were infective endocarditis. Pathogenesis of aortic insufficiency in patients with bicuspid aortic valves was discussed and compared with that of aortic stenosis.

Adult↗
PubMed1992

[Differential diagnosis between acute rejection and infection after lung transplantation in rats].

Infiltration of mononuclear cell subpopulations was analyzed immunohistochemically in acute lung allograft rejection (BN/LEW) and mycoplasma pulmonis bronchopneumonia in inbred rats. In lung allograft rejection, marked infiltration of activated macrophages, moderate infiltration of helper and suppressor T lymphocytes, and slight or moderate infiltration of B lymphocytes were observed around bronchioles and vessels, as a thick layer of cells like concentric circles, forming a dense cuff. In acute and chronic mycoplasma infection, focal inflammatory reactions were observed with various degrees of infiltration of mononuclear cell subpopulations around bronchioles and vessels, ranging from very mild to severe infiltration, even in the same section or even around the same bronchiole. This difference in the infiltration pattern between the focal, unequal and dappled infiltration in lung infection and the homogeneous and even cuff infiltration in acute rejection may be useful in differential diagnosis between acute rejection and infection following lung transplantation.

Animals↗
PubMed1991

[Current problems in valvular surgery].

Based upon our experiences of 661 valvular operations for these 10 years, we discussed about three major topics in valvular surgery. The first is the current status of valve repair versus replacement. The second is on the changing aspects of patients undergoing valvular surgery. Finally difficult problems in the treatment of infective endocarditis was discussed.

Aged↗