[Stanford type A acute aortic dissection with congenital complete absence of the left pericardium; report of a case].

A 52-year-old woman who presented with acute onset of chest pain was diagnosed with Stanford type A acute aortic dissection by computed tomography at another hospital. She was referred to our department for emergency surgery. The left pericardium visualized via a median sternotomy was clearly defective, and the left phrenic nerve was located ventral to the defect. The ascending aorta and total arch were replaced with an aortic valve and a prosthetic graft, respectively. Postoperative chest radiography excluded left phrenic nerve palsy. The postoperative course was uneventful and the patient was discharged on postoperative day 17.

[Surgical treatment of left ventricular pseudoaneurysm after acute myocardial infarction in subacute phase; report of a case].

A 81-year-old man who was complaining of chest pain was admitted. He was diagnosed as acute myocardial infarction. Coronary angiogram was performed and an occlusion of the circumflex coronary artery (#13) was diagnosed. Percutaneous coronary intervention (PCI) was done successfully. Cardiac tamponade was showed on the 3rd day after PCI. Percutaneous pericardial drainage was done and his hemodynamic was improved. Transthoracic echocardiogram showed left ventricular pseudoaneurysm with 2 cm in diameter and expanding to 5 cm in diameter after 3 weeks. Patch closure was carried out under cardiopulmonary bypass on subacute phase. His postoperative recovery was uneventful. Left ventricular pseudoaneurysm is a rare complication of acute myocardial infarction (AMI) and surgical treatment of this disease was discussed.

[Surgical technique of displacement and retraction of the heart with a pigtail shaped hook and Tentacles Heart Positioner].

We describe a novel heart retracting system with Tentacles Heart Positioner (Sumitomo Bakelite, Tokyo) during off-pump coronary artery bypass grafting (OPCAB). The heart retracting system is composed of a pigtail shaped hook attached to a flexible Universal Stabilizer Arm (Estech, Minneapolis). After Tentacles suction device is applied on the surface of the heart, the retracting system is fixed on the sternal retracter so that the hook can hang and support the retracting tubes of the sucker. By regulating the shape of the Universal Stabilizer Arm and the position of the hook, the retracting system can lift the heart sufficiently and maintain the optimal position of the heart during OPCAB procedure. Together with Tentacles Heart Positioner, the heart retracting system provides excellent exposure of target coronary arteries with minimal effect on hemodynamics.

[A case of pulmonary arteriovenous fistula associated with cerebellar abscess].

We report a rare case of pulmonary arteriovenous malformation (PAVM) with cerebellar abscess. The patient was 38-year-old woman who admitted to the local hospital for headache and fever. Subsequently, her condition became critical with consciousness disturbance, and hypoxemia. Brain computed tomography (CT) and chest CT revealed cerebellar abscess and PAVM. She was referred to our hospital for the surgery. Pulmonary angiography demonstrated multiple pulmonary arteriovenous fistulas in the right middle lobe and a single nodular pulmonary arteriovenous fistula in the right S8 (10 x 10 mm). After the drainage for the brain abscess, lobectomy of the right middle lobe and the excision of the nodal fistula in the right S8 were successfully performed in the two-staged operation. The patient has done well with no complication and her hypoxemia was improved.

[A case of free-floating ball thrombus in left atrium with mitral stenosis].

We report a rare case of free-floating ball thrombus in the left atrium with mitral stenosis. The patient was 71-year-old woman who admitted to the local hospital for transient ischemic attack. Electrocardiography showed atrial fibrillation and an echocardiogram examination revealed free-floating ball thrombus in the left atrium with mitral stenosis. She was transferred to our hospital for emergency open heart operation. After removal of the ball thrombus, mitral valve replacement and modified MAZE procedure were successfully performed. The size of the ball thrombus was 40 x 30 x 33 mm and weighed 20 g. Postoperative course was uneventful.

[Usefulness of OPCAB from the viewpoint of fluctuations in the level of blood natriuretic peptides].

Fluctuations in the level of blood natriuretic peptides (ANP and BNP) were compared between 41 patients who underwent conventional coronary artery bypass (CCAB) and 19 patients who underwent off-pump coronary artery bypass (OPCAB). A blood sample was collected before surgery, and 6, 12 and 24 hours; 2, 3, 5 and 7 days; and 1 month after the end of extracorporeal circulation. There were no significant differences in left ventricular ejection fraction (LVEF) before and after surgery in either group or between the two groups. On average, 3.3 +/- 1.0 bypass grafts were used for the CCAB group, and 2.2 +/- 0.8 grafts for the OPCAB group. Furthermore, the maximum postoperative creatine phosphokinase-MB (CK-MB) level for the CCAB group was 49.1 +/- 17.5 IU/l, whereas that for the OPCAB group was significantly lower at 23.2 +/- 24.8 IU/l. The preoperative level of blood ANP for the CCAB group was 24.6 +/- 19.9 pg/ml while that for the OPCAB group was 39.3 +/- 29.5 pg/ml, but there was no significant difference between the two groups. In both groups, the level of blood ANP reached a peak three days after the end of extracorporeal circulation and then decreased after that point. Although the level of blood ANP for the OPCAB group decreased to 51.4 +/- 26.4 pg/ml one month after the end of extracorporeal circulation, that for the CCAB group one month after the end of extracorporeal circulation remained significantly high at 61.3 +/- 30.6 pg/ml, when compared to that before surgery. Furthermore, the preoperative level of blood BNP for the CCAB group was 40.0 +/- 35.2 pg/ml and that for the OPCAB group was 75.5 +/- 59.7 pg/ml, but there was no significant difference between the two groups. Then, in both groups, the level of blood BNP reached a peak 2-5 days after the end of extracorporeal circulation and then decreased after that. Whereas the level of blood BNP for the OPCAB group decreased to 96.4 +/- 56.0 pg/ml one month after the end of extracorporeal circulation, that for the CCAB group one month after the end of extracorporeal circulation remained significantly high at 160.3 +/- 106.2 pg/ml when compared to that before surgery. The levels of ANP and BNP increased postoperatively for both OPCAB and CCAB groups since the following events caused a great degree of stress on the heart: general anesthesia, cardiac herniation, stabilizer compression, regional blood flow blockage and reperfusion injury. Although the level of natriuretic peptides for the CCAB group remained high one month after the end of surgical stress, that for the OPCAB group returned to near the preoperative level one month later, thus supporting the notion that OPCAB is less invasive.

[A case of aortic valve replacement 3 years after coronary artery bypass grafting].

A rare case of aortic valve replacement (AVR) with poor left ventricular function, following coronary artery bypass grafting, was reported. The patient was 57-year-old man who received urgent CABG with 2 saphenous vein grafts 3 years ago. At that time, aortic regurgitation (AR) was grade 2. He suffered acute myocardial infarction 1 year after CABG because of the occlusion the saphenous vein graft to the obtuse marginal branch. Percutaneous transluminal angioplasty was successfully performed for occluded graft. Since then, however, AR increased gradually and the left ventricular function decreased. Three years after the initial operation, he was admitted again with congestive heart failure. Heart catheterization revealed grade 3 AR and 17% left ventricular ejection faction (LVEF). AVR was performed through a median sternotomy and 2 saphenous vein grafts were preserved. He showed uneventful postoperative recovery and is now very well with 40% LVEF.

[Management strategy for patients with coronary artery disease associated with valve disease].

BACKGROUND: The indication of combined operation of coronary artery bypass (CAB) and valve surgery is controversial. METHODS: Between April 1992 and January 2000, 13 patients underwent a combined operation with CAB and valve replacement, and 4 patients (2 were overlapped) who had had a previous CAB underwent a reoperative valve replacement. RESULTS: One patient who underwent AVR and reCAB 11 years after the initial CAB died. Another patient with preoperative MRSA pneumonia and received MVR and CAB died 4 months after surgery with MRSA sepsis. However, others showed an excellent post-operative course. The causes of necessitating the reoperation were: unawareness of aortic stenosis at the initial emergency CAB in 1 patient, progression of aortic stenosis in 1 patient, progression of aortic regurgitation in 1 patient, and progression of mitral regurgitation in 1 patient. CONCLUSION: The results of the combined CAB and valve replacement operation were acceptable. Patients with mild-moderate valve disease should be considered as candidates for valve surgery at the time of CAB.

[Indication and outcome in emergent coronary artery bypass graft for acute coronary syndrome].

Among 462 cases receiving coronary artery bypass graft (CABG) during the period from November 1991 to January 1999, emergency operation was performed within 24 hours for 27 cases. Male-to-female ratio was 21:6, and age of patients ranged from 50 to 83 years (average age: 65.9 years). Intra aortic balloon pumping (IABP) was used from preoperative period for 25 cases, and PCPS was used for one case. Operation was performed under cardiac arrest in 25 cases and under ventricular fibrillation in 2. Average number of grafts was 2.4 +/- 1.0 and perioperative mortality was 25.9%. The results of emergency cases were extremely low compared with mortality of palliative operation of 3.4%, whereas mortality has been improved to 12.5% (2/16) in the last two years. These results suggest that it is important for the improvement of the outcome in emergency CABG to prevent aggravation of circulatory dynamics and to shift to operation under stable conditions.

Diversity of molecular forms of plasma brain natriuretic peptide in heart failure--different proBNP-108 to BNP-32 ratios in atrial and ventricular overload.

OBJECTIVE: Recent studies have shown that plasma levels of brain natriuretic peptide (BNP)-32 and proBNP-108 are increased in heart failure (HF) and that the BNP-32 assay kit in current clinical use cross-reacts with proBNP-108. We investigated why proBNP is increased without processing in HF was investigated. DESIGN, SETTING AND PATIENTS: Plasma BNP-32 and proBNP-108 in normal individuals (n=10) and in patients with atrial fibrillation (AF) (n=18) and HF (n=132) was measured. BNP-32 and proBNP-108 in ventricular and atrial tissue and in pericardial fluid using a specific fluorescent enzyme immunoassay following Sep-Pak C18 (Waters, Milford, Massachusetts, USA) cartridge extraction and gel filtration was also measured. MAIN OUTCOME MEASURES: Levels of both BNP-32 and proBNP-108 were higher in HF than in control or AF (both p<0.01), and the levels of these peptides significantly correlated (r=0.94, p<0.001). The proBNP-108/total BNP (BNP-32+proBNP-108) ratio was widely distributed and lower in HF (0.33 (0.17)) than in control (0.41 (0.06), p<0.05) and AF (0.45 (0.04), p<0.002). The proBNP-108/total BNP ratio was higher in HF with ventricular than in HF with atrial overload (0.45 (0.10) vs 0.20 (0.11), p<0.001). Consistent with this finding, the major molecular form were proBNP-108 and BNP-32 in ventricular (n=6, 0.67 (0.04)) and atrial (n=7, 0.76 (0.05), p<0.0001) tissues, respectively. ProBNP-108 was also the major molecular form of BNP in pericardial fluid (n=8, 0.82 (0.05)). The proBNP-108/total BNP ratio increased and decreased with HF deterioration and improvement, respectively. CONCLUSION: These results suggest that BNP-32 and proBNP-108 is increased in HF and that the proBNP/total BNP ratio increases in association with pathophysiological conditions such as ventricular overload.

Mutation induced by drying of Escherichia coli on a hydrophobic filter membrane.

Drying of Escherichia coli to a required cellular water level was conducted on a hydrophobic membrane at the corresponding relative humidity. Mutation from an arginine auxotroph to the prototroph was induced by drying to a water activity (aw) of 0.53 and below, but not to an aw of 0.75 and above. The critical aw below which mutation occurred in the course of drying was similar to that for induction of deoxyribonucleic acid (DNA) strand breakage in the bacteria. Some ultraviolet or gamma-irradiation-sensitive strains, e.g., strains of carrying recA, recB, and uvrA recA were more sensitive to drying than the wild-type strains or strains carrying uvrA and polA. The DNA strand breakage of every strain was observed to be to a similar extent after drying to an aw of less than 0.53. The drying-resistant strains repaired the damaged DNA partially during postdrying incubation in a growth medium but not in phosphate buffer solution, while the drying-sensitive strains could not at all. Significant mutation on drying occurred in the wild-type strains, strains carrying uvrA and polA, but not in strains carrying recA. It is, therefore, concluded that the mutation is caused by errors in rec-dependent repair of the drying-induced breakage in DNA.

Deoxyribonucleic acid strand breaks during drying of Escherichia coli on a hydorohobic filter membrane.

Cells of Escherichia coli mounted on a hydrophobic filter membrane were dried under various vapor pressures. A mutant defective in deoxyribonucleic acid repair (uvrA recA) was more sensitive to drying at a water activity of 0.53 or below than the parent strain but not at a water activity of 0.75 and above. Sucrose gradient studies showed that single- and double-strand breaks of deoxyribonucleic acid occurred at a water activity of 0.53 or below, but no breaks could be observed at a water activity of 0.75 or above. These results were observed in all cells rehydrated with 0.03 M tris (hydroxymethyl) aminomethane-hydrocholoride buffer solution at 0 or 37 degrees C, in the presence or absence of oxygen, with saturated water vapor or with a hypertonic solution followed by a gradual dilution. Freezable water was detected in the cells only at a water activity above 0.75 by differential scanning calorimetry. Removal of unfreezable water of cells in the drying, therfore, might induce deoxyribonucleic acid strand breaks.

Involvement of autolysin in cellular lysis of Bacillus subtilis induced by short- and medium-chain fatty acids.

The addition of saturated C6, C8, C10, and C12 fatty acids appeared to lyse actively growing cells of Bacillus subtilis 168, as judged by a decrease in the optical density of the culture. Of these fatty acids, dodecanoic acid was the most effective, with 50% lysis occurring in about 30 min at a concentration of 0.5 mM. These conditions also decreased the amount of peptidoglycan estimated by the incorporated radioactivity of N-acetyl-D-[1-14C]glucosamine. At concentrations above 1 mM, however, bacterial lysis was not extensive. Dodecanoic acid did not affect autolysis of the cell wall. The lytic action of dodecanoic acid was greatly diminished in cells in which protein synthesis was inhibited and in an autolytic enzyme-deficient mutant. The results suggest that fatty acid-induced lysis of B. subtilis 168 is due to the induction of autolysis by an autolytic enzyme rather than massive solubilization of the cell membrane by the detergent-like action of the fatty acids.

Destruction of the outer membrane permeability barrier of Escherichia coli by heat treatment.

Heat treatment of a wild-type Escherichia coli strain at 55 degrees C in 50 mM Tris-hydrochloride buffer with or without 10 mM magnesium sulfate or HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) buffer at pH 8.0 caused an increase in cell surface hydrophobicity. By determining the location of n-hexadecane droplets attached to cells by phase-contrast microscopy, the septal and polar regions of heated cells appeared to become the most frequently hydrophobic. Some of the lipopolysaccharide molecules in the outer membrane were released from heated cells, and the cells became susceptible to the hydrolytic action of added phospholipase C. Heat-treated cells also became permeable to the hydrophobic dye crystal violet, which was added externally. The release of part of the outer membrane by heat treatment appeared to bring about the disorganization of the outer membrane structure and, as a consequence, to result in the partial disruption of the permeability barrier function of the outer membrane. Tris was found to enhance damage to the outer membrane by heat.

Disinfection of water with quaternary ammonium salts insolubilized on a porous glass surface.

Insoluble quaternary ammonium salts bound to porous glass showed antibacterial activity. An agent designated as G(12), which had a dodecyl alkyl chain, was selected for some antibacterial tests on comparison of it with the agent reported previously. The antibacterial activity of G(12) toward Escherichia coli was mainly due to the adsorption of cells and therefore gradually decreased during continuous treatment of a cell suspension. The lost G(12) activity was completely recovered by washing with ethanol, and the activity of refreshed G(12) decreased in the same manner as that of fresh G(12). The lost activity was, however, always recovered only by ethanol treatment. This indicated that G(12) might interact with cells more strongly by means of a hydrophobic force than an electrostatic one. The antimicrobial spectrum showed that G(12) was effective against not only bacteria but also yeasts.

Heat-induced blebbing and vesiculation of the outer membrane of Escherichia coli.

Thermal damage to the outer membrane of Escherichia coli W3110 was studied. When E. coli cells were heated at 55 degrees C in 50 mM Tris-hydrochloride buffer at pH 8.0, surface blebs were formed on the cell envelope, mainly at the septa of dividing cells. Membrane lipids were released from the cells during the heating period, and part of the released lipids formed vesicle-like structures from the membrane. This vesicle fraction had a lipopolysaccharide to phospholipid ratio similar to that of the outer membrane of intact cells, whereas it had a lower content of protein than the isolated outer membrane. After heating bacterial cells at 55 degrees C for 30 min, the resulting leakage from the cells of a periplasmic enzyme, alkaline phosphatase, amounted to 52% of the total activity, whereas no release of a cytoplasmic enzyme, glucose-6-phosphate dehydrogenase, was detected. The results obtained suggest that surface blebs formed by heat treatment almost completely consist of the outer membrane and that the blebs may be gradually released from the cell surface into the heating menstruum to partially form vesicles.

Antimicrobial characteristic of insoluble alkylpyridinium iodide.

Insoluble and soluble alkylpyridinium iodides (C8 to C18) were synthesized. The insoluble agents were quaternized 4-vinylpyridine-divinylbenzene copolymers. The insoluble agent [C12(50)] that contained 50% divinylbenzene and had a C12 alkyl chain was selected as the most suitable insoluble agent. C12(50) showed poor durability of the antibacterial activity, but C12(50), which had lost the activity, was refreshed by washing with ethanol. This washing became ineffective after a few cycles of antibacterial treatment and refreshment. Such C12(50) recovered the activity upon 1.0 N NaOH treatment. The antibacterial activity of C12(50) depended on its surface area. It showed high antimicrobial activity against gram-positive bacteria and also showed activity against gram-negative bacteria and yeasts. But the activities of C12(50) and laurylpyridinium iodide solution were different against some microbes. The antibacterial activities of the agents were investigated against Escherichia coli and Micrococcus luteus under various conditions. The activity of C12(50) was higher at a higher temperature or at a lower cell concentration. The activity of C12(50) decreased on addition of NaCl, glucose, or bovine albumin to the cell suspension or in 0.01 M sodium-potassium phosphate buffer. C12(50) showed less activity when cells were mixed with dead cells or the supernatant of dead cells killed in an autoclave. The mode of action of the laurylpyridinium iodide solution against E. coli and M. luteus was similar to that of C12(50) except for the influence of E. coli cell concentration.

Adsorption of Escherichia coli onto insolubilized lauryl pyridinium iodide and its bacteriostatic action.

Insoluble lauryl pyridinium iodide [C12(50)] was synthesized as an antimicrobial agent. Escherichia coli cells were not killed by C12(50) but only adsorbed onto it. Though cells on C12(50) could not grow in nutrient agar, they possessed the ability to develop once they were liberated from C12(50). The adsorption of cells onto C12(50) was inhibited by iodide anions released from C12(50) itself. The ability of C12(50) to adsorb was decreased by the adsorbed cells, but C12(50) could be reactivated by washing with alkaline solutions. It was, therefore, suggested that this adsorption was mainly due to the electrostatic interaction between cells and C12(50). The adsorption of cells onto C12(50) was confirmed by scanning electron microscopy.

Coronary artery bypass in dialysis patients.

This study evaluated the operative outcome of dialysis patients undergoing coronary artery bypass (CAB). In the past 6 years, 38 dialysis patients with a mean age of 57.5 years underwent CAB. Thirty-one operations were elective, and 7 were nonelective operations. Thirty-two operations were performed under cardiac arrest, 3 operations were performed under fibrillatory arrest, and 3 operations were performed without cardiopulmonary bypass. The average number of bypass grafts was 2.8. In all patients, the internal thoracic artery was used. Hospital mortality was 5.3%. Actuarial survival rates at 1, 3, and 5 years including all causes of death were 88%, 80%, and 72%, respectively. With improvements in perioperative management, coronary artery bypass can be performed with acceptable mortality and morbidity in dialysis patients. Complete revascularization without cardiopulmonary bypass is the ideal method and will increase in usage. However, the conventional CAB also provides acceptable results.