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H Ohzeki

Publications and source records attributed to H Ohzeki.

At least 37 records · Page 2Linked to original sources
PubMed1997

Evaluation of the thoracodorsal artery as an alternative conduit for coronary bypass.

Complete coronary revascularization using arterial grafts has been performed recently because of their improved patency rates. However, as the need to repeat coronary bypass surgery has become more frequent, it can be difficult to find adequate conduits for further bypass surgery. Therefore, we investigated the use of the left thoracodorsal artery (LTDA) as an alternative bypass conduit. The length from its origin, internal diameter, and number and location of branches were angiographically measured in 16 patients, and in situ blood flow volume and external diameter were intraoperatively measured in 8. Moreover, each specimen of the LTDA, the internal thoracic artery (ITA), and the inferior epigastric artery (IEA) were evaluated histologically. We found that the thoracodorsal artery has the same diameter as the ITA angiographically, and the same histological findings as the IEA. In conclusion, the thoracodorsal artery may be useful as a coronary arterial graft.

Coronary Angiography↗
PubMed1997

Effect of cardiopulmonary bypass on cytokine release and adhesion molecule expression in alveolar macrophages. Preliminary report in six cases.

Although recent studies have shown that adhesion molecules on alveolar macrophages are important in a variety of pulmonary diseases, there have been few studies on the phenotypic and functional changes of alveolar macrophages during cardiopulmonary bypass. To investigate the possible role of alveolar macrophages in activating pulmonary immunity during cardiopulmonary bypass, we measured the expression of adhesion molecules on alveolar macrophages and peripheral blood monocytes in patients undergoing cardiopulmonary bypass. Antigens were stained with monoclonal antibodies against adhesion molecules, and the expression of antigens was quantified by flow cytometry as the ratio of specific to nonspecific linear fluorescence. On alveolar macrophages obtained after the release of aortic cross-clamp, macrophages as compared with alveolar macrophages obtained before cardiopulmonary bypass, there was a significant enhancement of CD11a, CD11b, CD11c, and CD18. In addition, alveolar macrophages, but not peripheral monocytes, produced higher levels of TNF-alpha and IL-8 when they were cultured in vitro. A higher expression of CD11 and CD18 on alveolar macrophages and enhanced production of cytokines after release of the aortic cross-clamp may contribute to immune activation in lung by macrophage-lymphocyte interaction.

Adult↗
PubMed1996

NADPH-specific quinone reductase is induced by 2-methylene-4-butyrolactone in Escherichia coli.

2-Methylene-4-butyrolactone (MBL), an inducer of NAD(P)H:(quinone acceptor) oxidoreductase (EC 1.699.2) in animal cells, was found to induce NADPH-specific quinone reductase about 25-fold in Escherichia coli. MBL induced NADPH-quinone reductases with relative mobilities (Rm) of 0.70, 0.76 and 0.91 on polyacrylamide gel electrophoresis (PAGE). These three enzymes were found to be charge isomers with the same molecular size of 42 kDA. Two NADPH-quinone reductases (A and B) were purified to single proteins both with an apparent mass of 21 kDa on SDS-PAGE. Enzyme A corresponded to the activity of the band at Rm 0.76 with a minor active band at Rm 0.70, and enzyme B to the activity of band Rm 0.91. Both enzymes reacted exclusively with NADPH and were most active toward quinone derivatives and ferricyanide with the optimum pH at 7.0. The reaction followed a ping-pong mechanism with Km values for NADPH and menadione of 10.5 microM and 6 microM, respectively. The sequences of 20 amino acids at the N-terminal of enzymes A and B were identical, and furthermore coincided with that of the E. coli modulator of drug activity (mda66) submitted under the accession number U18656.

4-Butyrolactone↗
PubMed1996

Surgical implication of aortic dissection on long-term outcome in Marfan patients.

We herein review our 17-year surgical experience for the treatment of ascending aortic aneurysm in patients with Marfan syndrome to clarify the risks of increased mortality and reoperation. The subjects consisted of 15 patients who had all undergone surgery for the aortic root and ascending aorta at Niigata University Hospital between July 1978 and January 1995. Aortic valve replacement and ascending aortic wrapping were performed in 5 patients, Bentall or Cabrol operation in 6, and combined aortic arch reconstruction and Cabrol operation in 2, as the initial surgery. Patients who had an aortic dissection (Stanford type A) at initial surgery were assigned to group I (n = 7), while those with an aortic root aneurysm were assigned to group II (n = 8). In group I, 3 patients required a second operation for the remaining aortic arch aneurysm, and 1 died due to a late rupture of the distal aneurysm. In group II, no patient needed a reoperation; however, 1 died due to an intracranial hemorrhage and another due to composite valve graft failure and distal dissection. The results thus indicate that aortic dissection seems to affect long-term outcome, and therefore the combined repair of the aortic root and transverse arch is recommended in Marfan patients with aortic dissection involving the transverse aortic arch.

Adolescent↗
PubMed1996

Soft-X-ray damage to biological samples.

X-ray damage to biological samples was investigated in the wavelength region of 2.7-5 nm, which overlaps the so-called 'water-window', the wavelength range of 2.4-4.3 nm usually used in X-ray microscopy. Yeast cells and myofibrils were chosen as representatives of whole cell samples and motile protein systems, respectively. The samples were exposed to X-rays using an apparatus composed mainly of a laser-plasma X-ray source, a Wolter mirror condenser, and a sample cell. The yeast cells lost their dye exclusion ability when the X-ray flux was higher than 1 x 10(6) photons micron-2, while the myofibrils lost contractility when the X-ray flux was higher than 4 x 10(5) photons micron-2. These X-ray fluxes are lower than the flux required for the X-ray microscope observation of biological samples at a resolution higher than that of light microscopes.

Animals↗
PubMed1996

Is a bioprosthesis preferable in tricuspid valve replacement?

We reviewed clinical data on 29 patients (17 acquired disease and 12 congenital disease) who underwent tricuspid valve replacement using a Carpentier-Edwards porcine valve or a St. Jude Medical valve at Niigata University Hospital between January 1978 and October 1995, and analyzed risks related to the outcome. Age ranged from 8 to 62 years, and 17 females were included. New York Heart Association functional class was IV in 9 patients (31%). Previous valve surgery had been performed in 10 patients (34%). An urgent surgery was required in 4 patients and simultaneous mitral (with aortic) valve replacement in 13 (45%). Mean follow-up period was 6.7 years. Hospital mortality occurred in 5 patients (17.2%) and all of them had acquired valvular diseases with functional class IV. There were 6 late deaths and none of them related to the tricuspid prosthesis. Nonfatal morbidity occurred in 2 patients (a thrombosed valve and a chronic hemolytic anemia) with a St. Jude valve. Late functional class was I or II in all patients except 3 with severe left-ventricular dysfunction or bioprosthetic failure. Late postoperative echocardiographic examination showed moderate tricuspid stenosis or regurgitation in 3 patients with a Carpentier-Edwards valve. By the Kaplan-Meier method, functional class (P < 0.01) and baseline diseases (p < 0.05) were found to affect probability of freedom from cardiac- and/or valve-related mortality including hospital death. In conclusion, the present study indicates that similarly good outcome would be expected whether using a St. Jude Medical valve or a Carpentier-Edwards porcine valve, and that both functional class IV and combined acquired valvular disease are risk factors for mortality after tricuspid valve replacement. Patient-specific selection of the prosthesis would be preferable in tricuspid valve replacement.

Adolescent↗
PubMed1995

Surgery for cavoatrial extension of malignant tumors.

Surgical management for cavoatrial involvement of malignant tumors and its outcome is reported on for 6 patients; their age ranged from 55 to 79 years and 5 were male and 1 female. The basic disease was renal cell carcinoma in 5 cases and adrenal leiomyosarcoma in 1. Intracaval tumor extension was diagnosed by computed tomography, magnet resonance imaging, digital subtraction angiography, and echocardiography. The tumor was resected together with adherant vena cava and invaded right-atrial wall, using cardiopulmonary bypass and normo- or mild-hypothermia in 5 patients. The caval defect needed to be reconstructed with a slit GORE-TEX vascular prosthesis in 3 patients. In all patients the tumor resections were successful and without major complications. All patients survived and are well from 4 to 52 months after the surgery. It is concluded that such cavoatrial extensions of malignant tumors can be safely and accurately resected with the aid of cardiopulmonary bypass, with favorable early and late outcomes in patients who have no distant metastatic lesions.

Adrenal Gland Neoplasms↗
PubMed1995

[Cabrol's operation and the aortic arch replacement for Stanford type A dissecting aortic aneurysm].

Replacement of the aortic arch was performed simultaneously with Cabrol's operation utilizing modified selective cerebral perfusion (SCP) in a patient with a Stanford type A dissecting aortic aneurysm. Preoperative arteriography revealed that the dissection involved both common carotid arteries. For this reason, antegrade SCP was performed via the branches attached to the composite graft which were anastomosed to both of the common carotid arteries following clamping under deep hypothermia. The operation was successfully performed, and the patient's postoperative recovery was uneventful. This method of SCP is useful in the treatment of patients with prior difficulty or risk of cannulation.

Adult↗
PubMed1995

[Venovenous extracorporeal membrane oxygenation in an elderly patient with severe respiratory failure--report of a case].

A 69-year-old woman, who developed acute respiratory distress syndrome (ARDS) after coronary artery bypass grafting, underwent venovenous extracorporeal membrane oxygenation (V-V ECMO) because conventional ventilatory support was ineffective. We used a covalently bonded heparin surface ECMO system, including an artificial lung, a centrifugal pump, cannulas, tubing and connectors, that was maintained with low-dose systemic heparinization, the patient was weaned from ECMO after 186 hours. During ECMO, her platelet count was about half of the initial level and markedly elevated thrombin-antithrombin complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and D-dimer were decreased by the use of heparin and protease inhibitors. V-V ECMO seems to be useful even in patients with severe adult respiratory failure and can be performed safely if a heparin covalent circuit is applied.

Aged↗
PubMed1995

[Surgical treatment of 22 primary cardiac myxomas].

We report surgical treatment of 22 patients with primary cardiac myxomas, including 17 left atrial (LA), 3 right atrial (RA), 1 left ventricular and 1 right ventricular myxomas. Eighteen patients manifested congestive heart failure, and an embolic episode was observed in 5 patients preoperatively. Inflammatory laboratory findings were observed in 16 patients. One case of RA myxoma was complex cardiac myxoma. A transverse biatrial approach was useful for removal of large LA myxomas and when the attachment of the tumor was unconfirmed preoperatively. There were no hospital deaths. Stroke occurred in 1 and supraventricular arrhythmia in 3 patients in the early postoperative period. There were 2 late deaths unrelated to cardiac myxomas. No signs of recurrence have been observed.

Aged↗
PubMed1994

Carney's complex in association with right atrial myxoma.

The association between myxomas, spotty pigmentation, and endocrine overactivity is referred to as Carney's complex. This report describes the case of a 24-year-old woman with right atrial myxoma who presented with this association. The patient had a previously excised myxoid tumor of the breast and uneven facial pigmentation was observed, but no evidence of endocrinopathy was detected. The myxoma originated from the right atrial wall adjacent to the junction of the inferior vena cava and right atrium, and was successfully excised. A brief review of Carney's complex is provided after discussion of this rare case.

Adrenal Cortex Diseases↗
PubMed1994

[The changes on cerebral hemodynamics during selective cerebral perfusion cooling].

We studied the influence on cerebral hemodynamics with 10 pigs, weighing 25 to 30 kg, when the temperature of perfusion blood changed in both rapid cooling and rewarming, and in slow them. As for the protocol of temperature, we decided that rapid change was the large temperature gradient of more than 0.5 degree C/min, and slow change was the small gradient of less than 0.3 degree C/min. Cardiopulmonary bypass (CPB) was established with a flow rate of 60 ml/kg/min, and core cooling was performed until the temperature of the returned blood from internal jugular vein reached 25 degrees C/min. For selective cerebral perfusion (SCP), blood was infused into aortic arch with the clamp of descending aorta at the temperature of less than 20 degrees C. We measured regional tissue cerebral blood flow (TCBF), intracranial pressure (ICP), carotid arterial flow (CAF), and carotid arterial pressure (CAP), and PCO2 in both CPB and SCP. Rapid cooling during CPB caused an elevation in CAP, and marked decrease in CAF, ICP, and PCO2. In contrast, rapid rewarming caused the significant increase in CAF, ICP. Slow change did not cause marked difference in CAP, CAF, and ICP, and PCO2. Moreover, TCBF was not significant in both rapid and slow changes. On the other hand, rapid change in SCP caused a significant decrease in CAP, significant difference in CAF, ICP. Slow change did not cause significant difference in them as same as in CPB. In conclusion, we presume that the influence on cerebral hemodynamics is less in slow cooling and rewarming than in rapid changes.

Animals↗
PubMed1994

Long term clinical results with 19 mm or 21 mm standard aortic St. Jude Medical prosthesis.

Comparison of long term clinical results after aortic valve replacement with 19 mm or 21 mm vs. 23 mm or larger bileaflet prostheses has not yet been reported. Between December 1979 and September 1993, 80 consecutive patients who underwent isolated aortic valve replacement at Niigata University using a standard St. Jude Medical valve were assigned to small size group (19 mm and 21 mm, n = 34) or to large size group (23 mm or larger, n = 46). In the small size group, patient's age was older, body surface area smaller, female patients and calcified aortic stenosis were dominant (all p < 0.01). The left ventricular systolic dimension was shorter (p < 0.001), while the cardiothoracic ratio was similar to that of the large size group. All patients received warfarin treatment, and target thrombotest level was 15 to 25% (equivalent to INR 1.6 to 2.1). Actuarial survival rates including hospital death in the small size group (94% at fifth postoperative year) were comparable to those in the large size group. Cerebrovascular event occurred in two patients with the small size prosthesis (1.3%/pty) and three with larger prosthesis (0.9%/pty). Major hemorrhagic complication was not observed in either group. No significant difference was noticed in the proportion free from valve-related morbidity. In the patients with aortic stenosis (n = 41), the left ventricular posterior wall thickness decreased from 15 mm preoperatively to 11 mm late post surgery in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Two case reports of recurrent mediastinitis with chronic mediastinal fistula successfully treated with muscle flap re-transposition].

We experienced two cases of recurrent poststernotomy mediastinitis with chronic mediastinal fistula. Both cases had already received muscle flaps for post operative mediastinitis. However, chronic mediastinal fistula appeared after nine months in the first case, and eleven months in the second case. We removed the infected tissue and the predgets, which were used on the ascending aorta. Then closed the wound by the muscle flap closure. The chronic fistula were closed, and the functional and cosmetic results were excellent.

Female↗
PubMed1993

Extracorporeal membrane oxygenation for severe heart failure after Fontan operation.

A 10-year-old boy with tricuspid atresia and Glenn anastomosis underwent a modified Fontan operation. After the operation, the pressure in the inferior vena cava increased, leading to oliguria and ascites. After the creation of continuity between the superior vena cava and the inferior vena cava to reduce the pressure gradient, there remained an elevated right atrial pressure. Six days of extracorporeal membrane oxygenation effectively stabilized his hemodynamics and organ function and allowed an excellent outcome.

Angiography↗
PubMed1993

[A concomitant operation of aorto-coronary bypass graft and lung cancer: report of a case].

A case of a 66-year-old man with ischemic heart disease and lung cancer is reported. Chest roentgenogram revealed an irregular 2.8 x 2.0 cm mass in the right upper lobe. Coronary angiography showed 75-90% stenosis of the left anterior descending artery, and these lesions was suspected to cause perioperative myocardial infarction. A concomitant operation of aorto-coronary bypass graft and right upper lobectomy was performed through median sternotomy. A concomitant operation must be considered to be definitive and ideally preferable in selected cases.

Aged↗
PubMed1992

Mechanical circulatory assist by a roller pump system using hydrophilic heparinized polymer coated tubing.

We developed a circulatory assist system driven by a roller pump using hydrophilic heparinized polymer coated tubing. This system is easy to handle and does not require systemic heparinization. We applied it to 11 patients who failed to be weaned from cardiopulmonary bypass after open heart surgery. Left heart bypass was employed in 5 patients, right heart bypass in 1, combined left and right heart bypass in 2, and venoarterial bypass without oxygenation was done in 3 patients. The assisting flow rate ranged from 0.8 to 3.2 L/min, and the duration of the assist ranged from 5 h to 21 days. Six patients were weaned from this support, and 5 were discharged from the hospital. This system is beneficial for patients who failed to wean from cardiopulmonary bypass after cardiac surgery because of its simplicity and antithrombogenicity.

Aged↗