Nucleotide sequence of a cDNA for mouse squalene epoxidase.

A full-length cDNA encoding mouse squalene epoxidase was isolated by screening a mouse liver cDNA library with the rat squalene epoxidase gene as a probe. The cDNA had an open reading frame for a 572 amino acid polypeptide with a calculated molecular mass of 63.8 kDa. The predicted amino acid sequence of the mouse enzyme contained an FAD-binding motif, and was 93% identical to that of the rat enzyme. The former is one amino acid shorter than the latter. Blotting analyses showed that the mRNA is 2.8 kb in size and that a single copy of the gene is present in the mouse genome.

Identification of two splice isoforms of mRNA for mouse hepatocyte nuclear factor 4 (HNF-4).

Hepatocyte nuclear factor 4 (HNF-4) is a liver-enriched transcription factor involved in the expression of many liver-specific genes. In the preceding communication (Hata, S., Tsukamoto, T. and Osumi, T. (1992) Biochim. Biophys. Acta 1131, 211-213), we reported the presence of two isoforms of mRNA for HNF-4 in rat liver and kidney. The longer isoform contained a segment of 30 bases which was not present in the shorter one. As an initial step to determine whether or not other mammals have these mRNA isoforms, we isolated a cDNA for mouse HNF-4 using the rat HNF-4 gene as a probe. The cDNA had an open reading frame for a 465 amino acid polypeptide. The deduced amino acid sequence was remarkably conserved between mouse HNF-4 and rat HNF-4 (99.6% identical). Moreover, like the cDNA for the larger rat isoform, the mouse cDNA contained an extra segment of 30 bp in the coding region near the C-terminus. Blotting analyses showed that the mRNA is about 3.7 kb in size and that a single copy of the gene is present in the mouse genome. Next we carried out the polymerase chain reaction (PCR) using primers located just upstream and downstream of the extra segment. Two PCR products were amplified from a mouse liver cDNA library. Determination of their nucleotide sequences proved that they exactly corresponded to the two rat isoforms. Finally, we amplified a DNA fragment (1.1 kb in size) from mouse genomic DNA using the same PCR primers as above. Its nucleotide sequence unequivocally confirmed that different splice donor sites were used to generate the two isoforms.

Initial and 6-month results of biodegradable poly-l-lactic acid coronary stents in humans.

BACKGROUND: Although metallic stents are effective in preventing acute occlusion and reducing late restenosis after coronary angioplasty, many concerns still remain. Compared with metallic stents, poly-l-lactic acid (PLLA) stents are biodegradable and can deliver drugs locally. The aim of this study was to evaluate the feasibility, safety, and efficacy of the PLLA stent. METHODS AND RESULTS: Fifteen patients electively underwent PLLA Igaki-Tamai stent implantation for coronary artery stenoses. The Igaki-Tamai stent is made of a PLLA monopolymer, has a thickness of 0.17 mm, and has a zigzag helical coil pattern. A balloon-expandable covered sheath system was used, and the stent expanded by itself to its original size with an adequate temperature. A total of 25 stents were successfully implanted in 19 lesions in 15 patients, and angiographic success was achieved in all procedures. No stent thrombosis and no major cardiac event occurred within 30 days. Coronary angiography and intravascular ultrasound were serially performed 1 day, 3 months, and 6 months after the procedure. Angiographically, both the restenosis rate and target lesion revascularization rate per lesion were 10.5%; the rates per patient were 6.7% at 6 months. Intravascular ultrasound findings revealed no significant stent recoil at 1 day, and they revealed stent expansion at follow-up. No major cardiac event, except for repeat angioplasty, developed within 6 months. CONCLUSIONS: Our preliminary experience suggests that coronary PLLA biodegradable stents are feasible, safe, and effective in humans. Long-term follow-up with more patients will be required to validate the long-term efficacy of PLLA stents.

Initial and long-term results of directional coronary atherectomy in unprotected left main coronary artery.

Angioplasty in the unprotected left main coronary artery (LMCA) has been controversial. Recently, several studies have suggested that new procedures and devices such as directional coronary atherectomy (DCA) and stents may change this situation. Although there are many reports of unprotected LMCA stenting, there are few reports of DCA of this lesion. Therefore, initial and long-term results were evaluated in 101 patients who underwent DCA for unprotected LMCA in our hospital. Emergency procedures were performed in 15 patients and electively in 86 patients. Scheduled angiographic follow-up was routinely performed, and all patients were clinically followed for >4 months after DCA. Technical success was achieved in 99%, and in-hospital outcomes were cardiac death (2%), noncardiac death (4%), Q-wave myocardial infarction (1%), non-Q-wave myocardial infarction (8.9%), coronary artery bypass grafting (0%), and repeat angioplasty (4%). In-hospital results varied considerably, depending on presentation. In-hospital mortality was significantly higher in the emergency, left ventricular ejection fraction < or =35%, and high-risk surgical subgroups. The angiographic restenosis rate was 20.4% at follow-up, and its predictor was postminimal lumen diameter by multivariate analysis. Mean clinical follow-up was 2.8 years; estimated 1- and 3-year survival rates were 87% and 80.7%, respectively. The cardiac survival rate of the low-risk surgical subgroup was significantly higher than that of the high-risk surgical subgroup (p <0.05). Thus, our data show that DCA can be performed safely and effectively in unprotected LMCA with an acceptable low restenosis rate and high survival rate.

Initial and long-term results of angioplasty in unprotected left main coronary artery.

Angioplasty of the unprotected left main coronary artery (LMCA) has been controversial. Although recent single-center studies suggest that new devices may change the situation, many questions and problems remain. Therefore, the results of unprotected left main coronary angioplasty of 175 procedures in 107 patients were analyzed to evaluate its feasibility and effectiveness. The treatment of the initial 107 cases included balloon angioplasty (39 cases, 36%), directional coronary atherectomy (53 cases, 50%), and stents (15 cases, 14%). They were divided into 3 major subgroups: (1) acute group (n = 14), in which LMCA angioplasty was performed in patients with acute myocardial infarction; (2) emergency group (n = 10); and (3) elective group (n = 83). In-hospital mortality was higher in the acute (35.7%) and emergency (40.0%) groups than in the elective group (3.6%; p <0.0001). Angiographic follow-up was routinely performed and the restenosis rate including in-hospital restenosis was 70% in the acute group, 37.5% in the emergency group, and 40% in the elective group (p = NS). The mean clinical follow-up period was 2.9 years, and the estimated 5-year survival rates of the acute and emergency groups were 50% and 48.2%, respectively. However the 5-year survival rate of the elective group was higher than that seen in the acute or emergency group (77.5%; p <0.05). Repeat LMCA angioplasty was performed in 37 of 68 patients with 8.8% mortality (38.5% of acute and emergency cases and 1.8% of elective cases). The results indicated that elective unprotected LMCA angioplasty is relatively feasible and effective under scheduled angiographic follow-up.

Catheter-based reperfusion of unprotected left main stenosis during an acute myocardial infarction (the ULTIMA experience). Unprotected Left Main Trunk Intervention Multi-center Assessment.

The ULTIMA registry was a prospective, multicenter, international registry of 277 patients who underwent percutaneous coronary interventions of unprotected left main trunk stenosis. The 40 patients who underwent an emergency percutaneous left main intervention for acute myocardial infarction are the focus of this study. We compared the results of primary angioplasty with primary stenting, characterizing both the short-term (in-hospital) and long-term (12-month) outcomes. Of the 40 patients, 23 underwent primary angioplasty, whereas 17 underwent primary stenting. The angiographic success rate was an 88% for the cohort. The in-hospital death or coronary artery bypass grafting rate was 65% for the entire group, 74% for the percutaneous transluminal coronary angioplasty group (PTCA), and 53% for the stent group (p = 0.2). The in-hospital death rate was 55% for the entire cohort, 70% for the PTCA group, and 35% for the stent group (p = 0.1). The 12-month rate of death or bypass surgery was 83% and 58% for the PTCA and stent groups, respectively (p = 0.047). The 12-month survival rate was 35% and 53% for the PTCA and stent groups, respectively (p = 0.18). Bypass surgery was required in 6 patients in the PTCA group and 2 patients in the stent group (p = 0.07). Patients undergoing percutaneous interventions for unprotected left main myocardial stenosis during an acute myocardial infarction are critically ill; an initial percutaneous revascularization approach appears feasible and may be the preferred revascularization strategy. Primary stenting was associated with improved clinical outcomes.

Cardiac myxoma: morphologic, histochemical, and tissue culture studies.

Twenty-one cases of cardiac myxoma exhibiting a variety of histologic findings were investigated by light and electron microscopy, tissue culture, and immunohistochemical studies for factor VIII-related antigen (FVIII-RA) and Ulex europaeus 1 (UEA-1) lectin. The cardiac myxoma cells revealed variable cellular arrangements, and some tumor cells revealed vascular-like channels. Immunohistochemically, FVIII-RA was found only in the endothelial-like cells covering the vascular-like channels or slits, whereas UEA-1 lectin reacted not only with myxoma cells having luminal structures or network-like arrangements but also with single cells. On electron microscopy, some myxoma cells revealed differentiation into cells forming vascular structures. In tissue culture, the tumor cells were polygonal and proliferated with extensions of the cytoplasmic processes. Arrangements suggesting vascular channels or slits were not observed. In a coculture of tumor cells and blood clot, the tumor cells covered the surface of the clot. However, angiogenesis was not observed in the tissue culture study. The results of our studies were inconclusive regarding the histogenesis of cardiac myxomas, but it was considered that cardiac myxoma is a neoplasm arising from mesenchymal cells with vasoformative characteristics.

Long-term results of valve replacement with the St. Jude Medical valve.

Between 1980 and 1992, 908 patients underwent single aortic (n = 178), single mitral (n = 577), or double aortic and mitral (n = 153) valve replacement with the St. Jude Medical valve at our hospital. There were 392 male patients and 516 female patients whose ages ranged from 1.2 to 74 years (mean, 52 years). The early mortality rate was 5.0% (45 patients). A 94% complete follow-up was accomplished for 863 patients who were discharged from the hospital (4682.3 patient-years). Sixty-nine of these patients died, for a late mortality rate of 8.0%. Fifty-two patients, including four patients (0.3%/100 patient-years) had anticoagulant-related hemorrhage, 4(0.1%/100 patient-years) had prosthetic valve endocarditis, 11 (0.2%/100 patient-years) had nonstructural valve dysfunction, and 16 (0.3%/100 patient-years) underwent reoperation. There were no structural valve failures in this series. The total number of valve-related deaths was 22. Of those patients who survived, 98% were in New York Heart Association functional class I or II at the date of the last follow-up. The probabilities of freedom from thromboembolism and anticoagulant-related hemorrhage at 10 years were 94% +/- 2% and 97% +/- 2% in aortic valve replacement, 89% +/- 2% and 98% +/- 4% in mitral valve replacement, and 89% +/- 6% and 92% +/- 6% in double valve replacement, respectively. Significant hemolysis related to the St. Jude Medical valve occurred in 8 of the 577 patients who received mitral valve replacement in our early experience, and modifying the valve orientation appeared to play an important role in reducing hemolysis. The event-free rate, including all complications and late deaths, at 10 years was 75% +/- 7%, 74% +/- 3%, and 81% +/- 6% in aortic valve replacement, mitral valve replacement, and double valve replacement, respectively. On the basis of these results, the St. Jude Medical valve seems to be an excellent mechanical valve in terms of durability and low thrombogenicity and remains our prosthetic valve of choice when valve replacement with a mechanical valve is indicated.

Effects of minimal-dose aprotinin on coronary artery bypass grafting.

OBJECTIVE: To evaluate the effects of minimal-dose aprotinin in patients undergoing coronary artery bypass grafting, we conducted a prospective randomized study. METHODS: A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose aprotinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55). Blood loss and transfusion requirements, parameters of clotting and fibrinolysis, renal function, and early graft patency rates were assessed. RESULTS: Postoperative blood loss and transfusion requirements were significantly (p = 0.01) lower in both the minimal-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.05) less marked in the low-dose group than in the control group. The alpha 2-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevention of fibrinolysis by both aprotinin doses. No statistically significant differences in postoperative renal function and early vein graft patency rates were noted (control group, 93.8%; minimal-dose group, 95.5%; low-dose group, 92.3%; p = 0.25). CONCLUSIONS: Aprotinin was not associated with a significant increase in the prevalence of renal dysfunction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dose of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operations.

Changes in lymphocyte subsets, mitogen responsiveness, and interleukin-2 production after cardiac operations.

We studied 104 patients after cardiac operations to search for changes in peripheral blood lymphocyte subsets, mitogen responsiveness, and interleukin-2 production. Mononuclear cells obtained from 10 patients with cholecystectomy were examined as control samples. Cultures for phytohemagglutinin and interleukin-2 production were incubated in microtiter plates for 24 hours with cells labeled with tritium thymidine used as target cells. Lymphocyte subsets were measured by using monoclonal antibodies. The results obtained with preoperative blood samples were compared with those from the first, third, and seventh days after operation. In patients having cardiac operations, mitogen responsiveness was low on both the first and the seventh days after operation and interleukin-2 production was markedly depressed (greater than 90% depressed) on the first postoperative day. However, in control samples from patients having cholecystectomy, lymphocyte subsets, mitogen responsiveness, and interleukin-2 production showed no significant changes. Improvement in interleukin-2 production occurred immediately in patients without blood transfusion from random donors and reached normal levels by postoperative day 3. However, interleukin-2 production remained depressed on day 3 in all patients with transfusion from random donors and remained significantly diminished even on day 7 in such patients in New York Heart Association classes III and IV. We conclude that heart operations for which cardiopulmonary bypass is used are associated with depression of cellular immunity, including interleukin-2 production. Furthermore, it appears that both blood transfusion from random donors and the general preoperative condition of the patients contribute to suppression of measures of cell-mediated immunity.

Aortic root replacement with a composite graft: results of 69 operations in 66 patients.

Between December 1973 and December 1992, 66 patients underwent aortic root replacement at our hospital. The mean age of the patients was 42.5 years (range, 20 to 71 years); 44 patients were male and 22 were female. Of the 66 patients, 34 (51.5%) had clinical stigmata of Marfan's syndrome. The aortic pathology requiring aortic root replacement was annuloaortic ectasia in 59 patients, aortic dissection in 5, and progressive dilatation of the ascending aorta after aortic valve replacement in 2. Twelve of the 59 patients with annuloaortic ectasia also had aortic dissection. The operative techniques used were the Bentall technique in 36 operations, the Cabrol technique in 21, the aortic button technique in 3, and other miscellaneous techniques in 9. The hospital mortality rate for the primary operation was 10.6% (7 patients), and the late mortality rate was 20.3% (12 patients). Four of the late deaths were related to the graft valve prosthesis, and 6 were related to the progression of aneurysmal diseases on the remaining aorta. The survival rate was 71.0% at 10 years. Pseudoaneurysm at the suture lines was detected in 7 patients, 6 of whom had been treated with the Bentall technique, and 5 patients also had Marfan's syndrome. No patients having aortic root replacement with the Cabrol technique have required reoperation for pseudoaneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Operation for type B aortic dissection using hypothermic selective cerebral perfusion.

A 56-year-old man who had a huge type B dissecting aortic aneurysm extending from the distal arch to the thoracoabdominal aorta underwent replacement of the descending thoracic and thoracoabdominal aorta under hypothermic circulatory arrest with selective cerebral perfusion. The intercostal arteries at the T-8 to T-11 level were preserved with beveled distal anastomosis, and the celiac artery and the intercostal arteries at the T-5 and T-6 levels were reconstructed. The patient recovered uneventfully and is presently doing well 1 year after the operation.

The surgical treatment of aortic regurgitation secondary to aortitis.

We describe the operative and perioperative management of 11 patients with aortic regurgitation due to aortitis. All patients required aortic valve replacement because of severely uncoapted cusps secondary to dilatation of the ascending aorta. The right coronary ostium was narrowed in 5 patients and consequently necessitated a smaller coronary tip for the administration of cardioplegic solution. To implant the prosthetic valve, pledgeted 2-0 Tevdek sutures were placed through the aortic valve annulus either from the ventricular side or from outside the aortic wall. Steroids were administered to 4 patients preoperatively and 8 patients postoperatively. Postoperative dehiscence of the prosthesis was seen in 1 of the 3 patients not given any steriods. We conclude that it is important to arrest the inflammatory reaction before operation and if the aortic valve must be replaced, to reinforce the implanted prosthesis with pledgeted sutures. Also, we suggest the possible importance of steroid therapy.

Ventricular septal defect associated with aortic regurgitation.

The effectiveness of aortic valvuloplasty and the indications for aortic valve replacement were examined in 76 patients with ventricular septal defect associated with aortic regurgitation. Results of this study indicate aortic regurgitation is associated with rapid deterioration and that aortic valvuloplasty should be performed as soon as aortic regurgitation is detected. The data also suggest that aortoplasty is indicated if aortic valvuloplasty alone is inadequate for coaptation of the aortic cusps with thickening.

Mitral valve repair for mitral regurgitation with ventricular septal defect in children.

BACKGROUND: We examined the results of intermediate and long-term follow-up of 25 patients aged 3 months to 11 years (mean, 2.6 +/- 2.3 years) who initially underwent conservative mitral valve repair for mitral regurgitation associated with ventricular septal defect between April 1973 and March 1991. METHODS: The preoperative degree of mitral regurgitation was 2+ in 3, 3+ in 17, and 4+ in 5 patients, and the major causes of mitral regurgitation were annular dilatation and prolapse of the anterior leaflet. Annuloplasty was performed in all except 2 patients, suturing of the cleft was done in 3 patients, and posterior mitral leaflet advancement was done in 2 patients. In addition, the papillary muscle was incised and adhesive chordae were removed in 1 patient, and adhesive fused chordae were detached from a leaflet in 1 other patient. RESULTS: There were no early deaths. Two patients with residual mitral regurgitation with or without mitral stenosis underwent reoperation for mitral valve replacement 2 months and 6 years after the mitral repair, respectively. Late death occurred in 2 patients, and the actuarial survival rate was 92.0% at 15 years after operation. The freedom from reoperation was 91.3% at both 10 and 15 years after the initial operation. Postoperative color Doppler flow imaging was performed in 22 of the 23 survivors, and results showed no mitral regurgitation in 4, mild regurgitation in 14, and moderate regurgitation in 4 patients. Four patients presently have mitral stenosis, with a mean transmitral pressure gradient greater than 10 mm Hg. The residual lesion of moderate mitral regurgitation with or without mitral stenosis developed in 6 of 11 patients in whom bilateral mitral annuloplasty was applied after the initial operation. Nineteen of the 22 survivors without reoperation were in New York Heart Association class I, and 3 were in class II. CONCLUSIONS: Clinical improvement was observed after conservative mitral repair in most pediatric patients with ventricular septal defect. However, careful follow-up for growth potential still appears to be needed to detect changes in mitral regurgitation and the development of mitral stenosis after valve repair, especially after bilateral annuloplasty.

Preferential inhibition of inducible nitric oxide synthase by ebselen.

Ebselen, 2-phenyl-1,2-benzisoselenazole-3(2H)-one can preferentially inhibit the activity of inducible nitric oxide (NO) synthase with little inhibition of endothelial constitutive NO synthase within a certain concentration range. This suggests that ebselen deserves further in vivo studies to examine its possible application to the therapy of septic shock where inducible NO synthase is responsible for vasodilation.

Structure and function of nitric oxide synthases.

Nitric oxide (NO), which accounts for the biological activity of endothelium-derived relaxing factor, is now thought to play a variety of roles in the nervous system and in immunologic reactions. NO is synthesized from L-arginine by nitric oxide synthase (NOS). There are three isoforms of NOS; type I (neuronal), type II (inducible), and type III (endothelial). The fundamental structure of the three isoforms, which contain calmodulin-, FMN-, FAD-, and NADPH-binding domains, is the same. Calmodulin is already bound to inducible NOS without requiring Ca2+, while the others are Ca2+/calmodulin-dependent. Endothelial NOS is bound to membranes by N-myristoylation, while the other isoforms are soluble. The human endothelial NOS gene has been cloned. It has several highly repetitive regions which could provide potential sites for DNA polymorphism. It might be of interest to examine the relationship between such polymorphism and cardiovascular disorders.

Long-term prognosis after thrombolytic therapy for acute myocardial infarction.

In order to clarify the relationship between the patency of the infarcted arteries and subsequent long-term prognosis after thrombolytic therapy, we evaluated 116 patients with acute myocardial infarction treated with intracoronary (112 patients) or intravenous (four patients) urokinase. Patients treated with angioplasty after thrombolysis were excluded. The infarcted vessel was recanalized in 52 patients (patent group) and was not in the remaining 64 patients (occluded group). Five-year and 8-year follow up was conducted in 91% and 81% of the patients, respectively. The 1-, 5- and 8-year survival rate for the patent and occluded group was 91.8 and 80.9%, 80.8 and 79.2%, and 75.9 and 75.6%, respectively. The survival rate in the patent group tended to be higher than that in the occluded group up to 4 years. However, after 5 years, both groups showed similar survival rates. Therefore, reopening of the infarcted arteries with thrombolysis was not an independent predictor for late cardiac death (Cox regression analysis).

Doppler echocardiographic evaluation of St. Jude Medical valves in the tricuspid position.

Sixteen of 20 patients who underwent tricuspid valve replacement with a St. Jude Medical valve at our hospital were followed for three to 164 months. Doppler echocardiographic and cineradiographic examinations of the replacement device were performed in 13 patients. There were six males and seven females in the study, with a mean age of 41.9 years. A St. Jude Medical prosthesis had also been implanted in the mitral or mitral and aortic positions of eight of these thirteen patients. Ten patients had normally functioning valves in the tricuspid position and three were diagnosed as malfunctioning. The peak velocity in those patients with normally functioning tricuspid valves was 1.3 +/- 0.2 m/sec. The calculated peak and mean pressure gradients were 6.7 +/- 1.9 mmHg and 2.6 +/- 1.1 mmHg, respectively, and the mean pressure half-time was 120 +/- 22 msec. All normally functioning valves in the tricuspid position had peak velocities of less than 1.55 m/sec, and peak and mean pressure gradients of less than 9.6 mmHg and 5 mmHg, respectively, with the pressure half-time being less than 140 msec in all cases, except for one of the three Doppler studies performed in one patient. However, three Doppler studies performed in two patients with a malfunctioning tricuspid valve revealed peak velocities, peak and mean pressure gradients and pressure half-times which were above these values. After replacement of the malfunctioning valve, or thrombolysis, all of the Doppler-derived values returned to the range found in normally functioning valves.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic root replacement for annuloaortic ectasia in Shprintzen-Goldberg syndrome: a case report.

Annuloaortic ectasia due to Shprintzen-Goldberg syndrome (SGS) is reported. A 10-year-old boy was admitted to our hospital for evaluation of chest pain. On admission, he was diagnosed as SGS on the basis of his various anomalies. Two-dimensional echocardiography showed a bicuspid aortic valve and marked annular dilatation, Doppler flow studies revealed severe aortic regurgitation, and retrograde aortography showed severe aortic regurgitation with annular dilatation. Successful aortic root replacement was performed; subsequent histologic examination of the ascending aorta demonstrated cystic medial necrosis. In conclusion, SGS is a generalized connective tissue dysplasia, with clinical manifestations of cardiovascular lesions similar to those in Marfan syndrome. Aortic root replacement was successfully performed; however, recurrence of aortic aneurysms outside of the ascending aorta should be carefully observed. Surgical treatment for cardiovascular disorders may be necessary to save the life of patients with SGS.