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The c-kit receptor tyrosine kinase (KIT) is constitutively activated by naturally occurring mutations in either the juxtamembrane domain or the kinase domain. Although the juxtamembrane domain mutations led to ligand-independent KIT dimerization, the kinase domain mutations (Asp814 → Val or Tyr) did not. In an effort to determine if the kinase domain mutant could transfer oncogenic signaling without receptor dimerization, we have constructed the truncated types of c-kitWild and c-kitTyr814 cDNAs (c-kitDel-Wild and c-kitDel-Tyr814 cDNAs, respectively), in which ligand-binding and ligand-induced dimerization domains were deleted. When c-kitDel-Wild and c-kitDel-Tyr814 genes were introduced into a murine interleukin-3 (IL-3)–dependent cell line Ba/F3, KITDel-Tyr814 was constitutively phosphorylated on tyrosine and activated, whereas KITDel-Wild was not. In addition, Ba/F3 cells expressing KITDel-Tyr814(Ba/F3Del-Tyr814) grew in suspension culture without the addition of exogenous growth factor, whereas Ba/F3 cells expressing KITDel-Wild (Ba/F3Del-Wild) required IL-3 for growth. The factor-independent growth of Ba/F3Del-Tyr814 cells was virtually abrogated by coexpression of KITW42 that is a dominant-negative form of KIT, but not by that of KITWild, suggesting that KITDel-Tyr814 may not function as a monomer but may require receptor dimerization for inducing factor-independent growth. Furthermore, KITDel-Tyr814 was found to be coimmunoprecipitated with KITWild or KITW42 by an ACK2 monoclonal antibody directed against the extracellular domain of KIT. Moreover, KITW42 was constitutively associated with a chimeric FMS/KITTyr814 receptor containing the ligand-binding and receptor dimerization domain of c-fmsreceptor (FMS) fused to the transmembrane and cytoplasmic domain of KITTyr814, but not with a chimeric FMS/KITWildreceptor even after stimulation with FMS-ligand. These results suggest that constitutively activating mutation of c-kit at the Asp814 codon may cause a conformation change that leads to receptor self-association not in the extracellular domain and that the receptor self-association of the Asp814 mutant may be important for activation of downstream effectors that are required for factor-independent growth and tumorigenicity.

Recent good results of cardiovascular surgery have led to expansion of its indication to elderly patients and patients with serious complications. Such patients may have serious respiratory complications after cardiac surgery and need to undergo tracheostomy relatively early in the postoperative period. Although the full sternotomy approach is the standard in almost all cardiac surgeries, superficial and deep sternal infections are rather common after early tracheostomy in full sternotomy patients. The lower partial sternotomy approach is a safer and more useful procedure in patients who will need tracheostomy in the early period after cardiac surgery. We report on 2 patients who were successfully tracheostomized within a week after cardiac surgery, with a review of the literature.

Isolated right aortic arch with mirror-image branching is a rare congenital anomaly. To date, no case has been reported for aortic dissection involving a right aortic arch with mirror-image branching. We report here on a case involving a 58-year-old man in whom expanding type B aortic dissection was demonstrated in the right aortic arch with mirror-image branching and a right descending aorta. The patient was successfully treated by interposition of a prosthetic graft via a right posterolateral thoracotomy approach. We also reviewed the literature.

Sternal infections and mediastinitis following coronary bypass grafting are rare, but the treatment for infection remains difficult and the mortality of these complications is reported high. We reviewed our experiences in treating two patients in whom post-sternotomy mediastinitis had developed after coronary bypass grafting. Sternal infections and mediastinitis were treated with debridement of the infected sternum, supra-sternal omental transfer with an open sternal technique, and a primary skin closure.

Although stem cell transplantation (SCT) is being used for hematopoietic reconstitution following high-dose chemotherapy for malignancy, it involves some serious transplant-related complications.1 For example, graft-versus-host disease (GVHD), and vascular disorders such as veno-occlusive disease (VOD), pulmonary vasculopathy, thrombotic microangiopathy (TMA) and capillary leak syndrome, are considered to be very important. In particular, TMA is a well-recognized disorder, and several factors contribute to the onset of this complication.2 In the case of SCT, patients generally receive granulocyte colony-stimulating factor (G-CSF) after chemotherapy. The administration of G-CSF can affect serum cytokine levels of these patients,3 resulting in the generation of procoagulant factors such as platelet-derived microparticles (PDMP).4 In addition, some cytokines, such as G-CSF, IL-6 and thrombopoietin, modulate platelet activation.5 When TMA is described in patients who have undergone allogeneic SCT, it is often implied that the clinical diagnosis of TMA is similar to that of thrombotic thrombocytopenic purpura (TTP). However, TMA exhibits no symptoms at the initial stage in most cases. If it advances to a further progressive stage, a TTP-like symptom occurs. And the decrease of vWF-CPase activity is hardly recognized in TTP after bone marrow transplantation. PDMPs have been associated with TTP, and endothelial cells and monocytes can develop the same microparticles. We measured and compared the levels of microparticles and soluble factors in patients undergoing allogeneic SCT.

Coarctation of a right aortic arch is rare congenital anomaly. We report a rare case of a 24-year-old female with coarctation of the right aortic arch with aberrant left subclavian artery between the right common carotid and right subclavian arteries. The coarctation progressed into complete obstruction as the interruption of the aorta in adulthood. To prevent cerebral complications and progression to heart failure, surgical procedure was selected. Extraanatomical bypass grafting between the ascending and descending aorta was successfully performed using cardiopulmonary bypass. Some patients diagnosed with interruption of the aortic arch in adulthood might be displaying progression of undiagnosed coarctation, as our in case. Three-dimensional computed tomography was useful to detect the obstructive lesion and to determine the surgical approach and methods.

Since June, 1998, modified ultrafiltration (MUF) was performed for 92 consecutive children who underwent cardiac surgery using cardiopulmonary bypass, except those with atrial septal defect. Among 92 cases, MUF could not be completed in two cases because of the accident that many air bubbles were found in the arterial line of the CPB circuit. The causes of such trouble were discussed.

Pulmonary stenosis (PS) and regurgitation (PR) are major concerns late after transannular patching for tetralogy of Fallot (TOF). In this study, we reviewed the TOF patients undergoing transannular patching to reveal whether the valvuloplasty technique (two cusp plasty) improved long-term results. We also reviewed potential for grow of the pedicled autopericardial patch.Since 1977, 151 patients underwent corrective surgery for TOF. Transannular patching was required in 58 (38.4%). PS and PR in the postoperative long-term period of these 59 cases were reviewed. 25 patients had the standard transannular patching (S-TAP), and 33 had two-cusp plasty (TCP). Pedicled autologous pericardial patch were used in 9 patients of TCP. Actuarial freedom from PS at 7 years was 70.8 +/- 9.2% in S-TAP and 79.2 +/- 8.3% in TCP, and there was no significant difference. Incidence of severe PR was significantly higher in S-TAP (7/24) than TCP (1/24) (p0.05). Actuarial freedom from PR at 7 year was 69.6 +/- 9.6% in the former and 95.8 +/- 4.2% in the later, respectively. The diameter of the pulmonary arterial annuals was augmented with the somatic growth in 6 patients with the pedicled pericardial patch.Two cusp plasty was more effective to prevent PR in the postoperative long-term period, comparing to S-TAP. As the material of the patch, pedicled autologous pericardium showed satisfactory outcome.

PET with a double-head gamma camera (hybrid PET) is a new approach to tumor imaging with 18F-FDG. This study was conducted to clarify the feasibility of whole-body FDG hybrid PET in the staging of non-Hodgkin's lymphoma (NHL) in comparison with PET with a dedicated camera (dedicated PET) and to compare the results of both FDG studies with those of CT and 67Ga scanning as conventional imaging studies (CIS).Thirty patients with NHL were prospectively evaluated. The results of the imaging studies regarding detection of the sites involved and staging were compared with each other and with those of the reference standard based on the final overall clinical evaluation.Of the total of 206 sites, whole-body FDG hybrid PET and dedicated PET detected 159 sites (77.2%) and 179 sites (86.9%), respectively. Eighteen of the 20 sites missed by hybrid PET alone consisted of lesions1.5 cm. Both FDG studies provided concordant staging results in all but 2 patients. CIS, on the other hand, detected 164 (79.6%) of the 206 sites, 137 of which were also detected by hybrid PET. Hybrid PET detected an additional 22 sites not found by CIS, whereas CIS detected 27 additional sites. Hybrid PET and CIS provided concordant staging results in 19 patients. Hybrid PET correctly staged NHL in 5 additional patients, whereas CIS correctly staged NHL in only 1 additional patient.Whole-body FDG hybrid PET appeared to be an accurate method of staging NHL. Despite its poorer image quality compared with dedicated PET, hybrid PET provided NHL staging results comparable with those of dedicated PET. Hybrid PET also yielded results comparable with those of CIS. However, whole-body FDG hybrid PET is currently inadequate as a single modality for staging NHL and is complementary to CT.

The aging of the Japanese population and improvements in surgical techniques have resulted in an increasing number of elderly patients undergoing coronary artery bypass grafting (CABG). We reviewed the records of 11 patients 80 years of age or older (mean age 82+/-0.38 years, range, 80 to 85 years) who had undergone a CABG at our institution between August 1989 and February 1999. Eight patients were males and 3 were females. Preoperatively, 4 of 11 patients were categorized as New York Heart Association class II, 4 as class III, 3 as class II. The operations were elective in 8 cases, and emergent in 3. Three patients presented with neck and cerebrovascular disease. One patient experienced chronic renal failure. No patients died within 30 postoperative days and no in-hospital deaths occurred. A total of 11 were followed up for an average of 35+/-11 months (range, 1 to 105 months). One patient died due to unknown causes. There was a significant decrease in overall anginal symptoms after CABG among the survivors, with the average decrease being from NYHA class 3.1 to 1.5. In conclusion, CABG is a safe and effective surgical procedure in the treatment of octogenarians with heart disease.

We performed extracardiac total cavopulmonary connection using only native tissue in two patients with complex heart disease. The extracardiac lateral tunnel was constructed from pedicled autologous pericardium and atrial wall During follow-up both patients remained in the New York Heart Association functional class I and demonstrated normal sinus rhythm. These modifications not only avoid the risk of potential postoperative complications due to artificial materials, but also allow growth of the conduit.

A truncated MSX-2 homeoprotein was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in untransformed cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a full-length human MSX-2 cDNA and tested its activities in two cell systems: fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated MSX-2 cDNA interfered with the transforming activities of both v-Ki-ras and v-raf oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and truncated MSX-2 cDNA was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that the truncated version MSX-2 may act as a dominant suppressor of intact MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.

We present two patients with thromboembolic pulmonary hypertension associated with unusual complications probably caused by disseminated fibromuscular dysplasia (FMD) or FMD-like vascular lesions. Intimal fibroplasia, which is typical of the vascular lesions associated with FMD, was observed in both patients. The presence of such intimal lesions suggests that there was a systemic factor that caused the formation of recurrent thrombi in the systemic vessels in these patients. These cases are the first ones reported in which an association between FMD and pulmonary hypertension has been observed. The pathogenesis of the thrombi in our patients was thought to be recurrent pulmonary thromboembolisms resulting from FMD.

Patients with vascular disease has a high incidence of coexistence of coronary artery disease and patients with coronary artery disease can be associated with aortic or peripheral vascular occulusive lesions. Simultaneous coronary artery bypass grafting (CABG) and surgery for coexistent vascular lesions was performed in 13 patients from October 1991 until September 1995. Average number of graft for CABG was 3.5. For vascular lesions, fomoro-popliteal artery bypass was performed on four patients, aorto-both side iliac artery bypass using bifurcated prosthesis on there, aorto-iliac artery bypass on one, carotid endarterectomy on three and aorto-subclavian artery bypass on two patients. All patients survived without any major complications. There were no late death noted in the longest follow-up period of 42 months. Simultaneous surgical procedures for coronary arterial and other vascular lesions can be performed with acceptable risk and may offer physiological, psychological, social and echonomical advantages to avoid rehospitalization and repeated surgical interventions.

The surgical and postoperative long-term results were assessed in 55 patients undergoing correction of complete atrioventricular septal defects. The patients was divided into two groups according to mode of plasty of the atrioventricular valve: 45 patients in whom the cleft was closed in the earlier series, and 10 with trifoliated mitral valve, leaving the cleft unclosed in the later series. The early death occurred in 13 of 45 patients in the earlier series and none in the later series. During 11 years follow up period, mitral valve regurgitation of grade 3 and 4 was observed in 20% of the patients, respectively, in the earlier series. In contrast, grade 3 mitral regurgitation was detected in only one and no grade 4 regurgitation was present in the later series. Tricuspid valve regurgitation was irrelevant. In the later series, the diameter of the mitral valve was greater than the average value of Rowlatt's standard by 3.4 mm after partisioning the common atrioventricular valve into mitral and tricuspid components, and smaller than the normal by 0.2 mm, though the diameter was within the normal range after valvulo-and annuloplasty. On the other hand, the diameter of the tricuspid valve was also greater than the normal value by 1.7 mm after partisioning, however, that was smaller than the normal by 1.7 mm after valvulo-and annuloplasty, on the average. The diameter was smaller than the normal lower limit by one standard deviation in two patients. There was present neither mitral nor tricuspid stenosis in all on the post-operative hemodynamic study.(ABSTRACT TRUNCATED AT 250 WORDS)

The c-kit proto-oncogene encodes a receptor tyrosine kinase that is known to play a crucial role in mast cell growth and differentiation. In a human mast cell leukemia cell line (HMC-1), KitR was found to be constitutively phosphorylated on tyrosine, activated and associated with phosphatidylinositol 3-kinase (P13K) in the absence of autocrine production of SCF. Sequencing of c-kit cDNA revealed that c-kit genes of HMC-1 cells were composed of a normal, wild-type allele and a mutant allele with two point mutations in codon 560 and codon 816, resulting in intracellular amino acid substitutions of Gly-560 for Val and Val-816 for Asp, respectively. Murine c-kit mutants encoding Gly-559 and/or Val-814, corresponding to human Gly-560 and/or Val-816, were constructed by site-directed mutagenesis and expressed in cells of a human embryonic kidney cell line (293T). In the transfected cells, KitR (Gly-559 + Val-814) and KitR (Val-814) were strikingly phosphorylated on tyrosine and activated in the absence of SCF, whereas tyrosine phosphorylation and activation of KitR (Gly-559) or wild-type KitR was modest or little, respectively. These results suggest that constitutive activation of KitR in HMC-1 results from the activating mutations of c-kit gene, and raise the possibility that the activating mutations, particularly at codon 814 of murine c-kit or at codon 816 of human c-kit, may participate in oncogenesis of mast cells.

Human interleukin 2 (IL-2) is a member of the class of crucial regulators of lymphocyte proliferation. The action of IL-2 is known to be mediated through binding to a specific IL-2 receptor (IL-2R) which comprises at least two distinct proteins: IL-2R alpha (p55) and IL-2R beta (p70-75). However, the expression and function of IL-2R are largely unknown in acute myeloblastic leukemia cells. In a human granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, or stem cell factor-dependent myeloid leukemia cell line (M07E), IL-2 was found to stimulate proliferation in a dose-dependent manner and to augment GM-CSF- and stem cell factor-induced proliferation of M07E cells. The expression of IL-2R beta on M07E cells was detectable with 125I-IL-2 binding and affinity cross-linking analyses and with a monoclonal antibody against IL-2R beta, Mik-beta 1. Although the expression of IL-2R beta was not down-regulated but somewhat up-regulated by treatment with GM-CSF in both mRNA and protein levels, GM-CSF was found to compete (75%) with radiolabeled IL-2 for binding to IL-2R on M07E cells, whereas no competition of GM-CSF binding was observed with IL-2 even at a 400-fold molar excess. These results suggest that IL-2R may be functionally expressed in some cases of acute myeloblastic leukemia cells and raise the possibility that IL-2 may have some effects on human myelopoiesis.

Apico-abdominal-aortic bypass operation was successfully performed for the left ventricular outflow tract obstruction 17 years after correction of Tausig-Bing malformation. At the age of 14 months old, a 18-year-old patient underwent total correction of Taussig-Bing malformation according to Kawashima's intraventricular re-routing. The right ventricular hemodynamics were normal throughout, however, systolic ejection murmur due to aortic stenosis appeared 3 years after repair. Seventeen years postoperatively, marked aortic valve and subaortic obstruction was detected corresponding with the internal conduit made from the duplicated autopericardial baffle. A composite graft containing 23A-SJM valve was interposed between the left ventricular apex and infrarenal abdominal aorta. After the bypass operation, thickness of the posterior wall of the left ventricle and interventricular septum was significantly reduced and symptoms were remarkably improved. The present paper is concerned with the subaortic stenosis after repair of Taussig-Bing malformation and technique of apico-aortic bypass operation.

We investigated the expression, degree of phosphorylation, and activation of the proto-oncogene c-kit product before and after stimulation with the c-kit ligand in a human factor-dependent myeloid leukemia cell line, MO7E. The culture supernatant of the BALB/3T3 fibroblast cell line, which contains the ligand for the murine c-kit product, was found to stimulate proliferation of the MO7E cell line in a dose-dependent manner. The proliferation was significantly inhibited by a tyrosine kinase inhibitor, genistein. An immunoblot technique with a monoclonal antibody specific for phosphotyrosine, showed that there was rapid, dose-dependent tyrosine-phosphorylation of the c-kit product in response to murine c-kit ligand. Furthermore, the murine c-kit ligand increased autokinase activity of the c-kit product in vitro. Similar results were obtained with human stem cell factor (SCF), a recombinant human ligand for the c-kit product. These results suggest that the phosphorylation and activation of the c-kit product are involved in proliferative signals of some human leukemia cells, as well as of normal hematopoietic cells.

We used a thin-sectioning technique for the electron microscopic detection of viral particles within the cells of urinary sediments in three recipients who developed hemorrhagic cystitis after allogeneic bone marrow transplantation. Results of viral cultures of urine and electron microscopic (EM) observations on urinary sediments were consistent in only one recipient. In this recipient, EM observations revealed many viral particles within the cells of urinary sediments with diameter of about 80 nm corresponding to adenovirus, of which type 11 was produced in viral cultures. In one of the other two recipients many viral particles with a mean diameter of 41.6 nm corresponding to papovavirus were observed, but viral cultures using conventional cells were negative. Re-cultures using HEK cells produced polyomavirus BK. EM observation was a clue to the correct diagnosis. In the remaining recipient, no viral particles were observed within the cells of urinary sediments, suggesting the hemorrhagic cystitis to be of non-viral origin, despite a positive result of viral culture. These results suggest that a thin-sectioning technique on the cells of urinary sediments is important for the differential diagnosis between a viral-induced and non-viral hemorrhagic cystitis.

A five year and six month old boy, who had undergone Mustard operation for complete transposition of the great arteries with intact ventricular septum at two months of age, was reoperated on for pulmonary venous obstruction and pulmonary hypertension (PLV/RV = 0.96). The other complications which he had were moderate tricuspid regurgitation and various supra-ventricular arrhythmias. After the atrial baffle of the Mustard procedure was taken down, atrial septum was reconstructed and arterial switch operation was performed at the same time. One month after the operation, Pp/Ps was 0.41 and no tricuspid regurgitation and arrhythmias were found. He was discharged and his quality of life was ameliorated surprisingly.

An 11-year-old girl with CML in chronic phase was treated with allogeneic bone marrow transplantation (BMT). She had had no episode of heart disease, and her chest roentgenogram and electrocardiogram were within normal ranges. She had no anthracycline, but 120 mg/kg (2.01 g/m2/d x 2 days) of cyclophosphamide (CY) for conditioning of BMT. She suffered from an acute heart failure on 14 days after BMT and died 2 days later. Autopsy revealed "specific heart muscular disease" with apparent degeneration and necrosis of heart muscle cells. More than 30 fatal cases of CY cardiotoxicity after BMT have been reported, and most patients developed acute heart failure within 10 days after CY dosing. Goldberg et al. reviewed 14 cases of CY cardiotoxicity, and considered more than 1.55 g/m2/day to be the critical doses for the onset of fatal cardiomyopathy. This case was considered to be first case in Japan. CY cardiomyopathy is an early fatal complication of BMT when CY used for conditioning. The dosing schedule may be considered.

A phase I/II study of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in 24 leukemia patients was conducted at our institute. Recombinant human G-CSF (50-200 micrograms/m2/day) was administered i.v. In seven allogeneic bone marrow transplantation (BMT) recipients, treatment with rhG-CSF was started 5 days after BMT. Neutrophils began to increase within 3 days after the start of rhG-CSF administration in five of seven patients. The mean duration necessary for recovery of neutrophils to greater than 500/microliters was 11.3 days after BMT with rhG-CSF; 26.8 days is the figure for recovery without rhG-CSF from Japanese historical data. In seven out of eight patients who received rhG-CSF administration after the first remission-induction chemotherapy, the neutrophil counts increased from less than 300/microliters to greater than 4000/microliters within 10 days. Blasts did not increase in all patients including four acute nonlymphocytic leukemia (ANLL) patients. Severe infections such as septicemia and pneumonia, which were unable to be controlled by antibiotics only, were successfully treated with rhG-CSF and antibiotics. rhG-CSF either stimulated or inhibited myeloid leukemic cells in some refractory cases. Mild bone pain occurred in one patient while receiving rhG-CSF i.v. rhG-CSF seems to have the ability to shorten the period of neutropenia, prevent infections after allogeneic BMT and remission-induction chemotherapy for acute leukemia, and support therapy for infections.

Flat revertants with reduced malignancy in vivo can be isolated from Kirsten sarcoma virus-transformed NIH3T3 cells following transfection with a normal human fibroblast cDNA expression library. We have recovered from one such revertant a 1.8 kb cDNA clone, "Krev-1", that possesses revertant-inducing activity in transfection assay. The Krev-1 cDNA has the capacity to encode a protein with a calculated molecular weight of 21,000 having strong structural similarity to ras proteins (ca. 50% homology), especially in their GTP/GDP-binding, effector-binding and membrane attachment domains. Point-mutations of Krev-1 protein at the 12th and the 59th amino acid positions from the aminoterminus potentiated the transformation suppressor activity by 2-5 times, and point-mutations within the putative effector-binding domain and at the C-terminal acylation site reduced the activity.