Balanced-size and long-size cloning of full-length, cap-trapped cDNAs into vectors of the novel lambda-FLC family allows enhanced gene discovery rate and functional analysis.

We have developed a new class of cloning vectors: lambda-full-length cDNA (lambda-FLC) cloning vectors. These vectors can be bulk-excised for preparing full-length cDNA libraries in which a high proportion of the plasmids carry large inserts that can be transferred into other (for example, functional) vectors. Unlike other cloning vectors, lambda-FLC vectors accommodate a broad range of sizes of eukaryotic cDNA inserts because they contain "size balancers." Further, the main protocol we use for direct bulk excision of plasmids is mediated by a Cre-lox system and is apparently free of size bias. The average size of the inserts from excised plasmid cDNA libraries was 2.9 kb for standard and 6.9 kb for size-selected cDNA. The average insert size of the full-length cDNA libraries was correlated to the rate of new gene discovery, suggesting that effectively cloning rarely expressed mRNAs requires vectors that can accommodate large inserts from a variety of sources. Part of the vectors are also suitable for bulk transfer of inserts into various functional vectors.

Primary cardiac angiosarcoma detected by magnetic resonance imaging but not by computed tomography.

A 51-year-old man with a primary angiosarcoma of the right atrium is reported. The angiosarcoma was not detected by transthoracic echocardiography or computed tomography, but magnetic resonance imaging and transesophageal echocardiography did show the tumor of the right atrial free wall. We performed a transvenous endomyocardial biopsy of the tumor under the guidance of transesophageal echocardiography and made the pathological diagnosis. This case demonstrates the advantage of magnetic resonance imaging and transesophageal echocardiography for tumor detection over transthoracic echocardiography and computed tomography and the usefulness of transesophageal echocardiography for guiding the right atrial endomyocardial biopsy procedure.

[Coronary flow after successful angioplasty in patients with acute myocardial infarction: comparison between coronary flow reserve by nicorandil and papaverine].

In order to evaluate coronary flow response to 2 different vasodilators, nicorandil and papaverine, in patients with myocardial infarction, we measured coronary flow reserve using a Doppler guide wire in infarct-related and non infarct-related arteries. The study group consisted of 28 patients with first acute myocardial infarction 3 weeks after successful coronary angioplasty within 6 hr after symptom onset. Twelve patients with atypical chest pain served as the control group. Coronary flow reserve induced by intracoronary papaverine(12 mg) was lower in infarct-related arteries than in non infarct-related arteries, but there were no differences in coronary flow reserve induced by intracoronary nicorandil(1 mg) between infarct-related and non infarct-related arteries. Coronary flow reserve induced by nicorandil was lower than that by papaverine in non infarct-related arteries and the control group. However, there were no differences between coronary flow reserve induced by nicorandil and papaverine in infarct-related arteries. Vasodilatory response induced by nicorandil was relatively preserved in infarct-related arteries compared with papaverine. These results suggest that impairment of coronary microvascular response in infarct myocardium varies in the different sites acted on by different vasodilator agents.

Clinical characteristics of patients with fresh left ventricular thrombus.

The present study analyzed the clinical backgrounds of 9 patients with fresh left ventricular thrombus (LVT) detected by two-dimensional echocardiography during the past 5 years. Patients with acute myocardial infarction were excluded. Left ventricular systolic function was disturbed either diffusely or segmentally in all patients with a mean ejection fraction of 33%. In 7 patients, echocardiography was performed shortly after furosemide therapy for New York Heart Association class IV congestive heart failure; echocardiography was also performed just before treatment in 4 of the 7 patients and LVT was not detected in any of them. Two patients died of underlying disorders within 2 months of detection of the thrombus. However, the LVT disappeared in the other 7 patients without any thromboembolic episodes during the 6 months after starting anticoagulant therapy. As fresh LVT developed shortly after diuretic therapy in patients with severe congestive heart failure associated with left ventricular systolic dysfunction, concomitant anticoagulant therapy is recommended.

Cytokine gene expression during the development of graft coronary artery disease in mice.

Immunologic injury to heart allografts is an initial and essential event in the pathogenesis of graft coronary artery disease (GAD). A variety of cytokines expressed in heart allografts modify both acute rejection and chronic inflammation, and could contribute to the development of GAD. The present study investigated the gene expression of interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and Fas ligand in chronically rejecting DBA/2-to-B 10.D2 mouse heart allografts at defined intervals of 7, 14, 28, or 70 days after transplantation by semiquantitative reverse transcriptase-polymerase chain reaction. GAD developed gradually, showing the highest value for mean intima/media ratio at day 70. Fas ligand, and the Th1 cytokines IL-2 and IFN-gamma, were vigorously induced in allografts at day 7, when histology showed pronounced parenchymal rejection, and rapidly decreased by day 28. However, the level of mRNA expression of Th2 cytokines, IL-6 and IL-10, and other inflammatory cytokines, TNF-alpha and IL-1beta, were still elevated on day 28. The persistent expression of specific cytokines suggests an important role in chronic inflammation. Thus, a persistently high level expression of inflammatory cytokines could be associated with chronic inflammation in the allografts, which promotes the development of GAD.

Protective effects of Mu-Fang-Ji-Tang against myocardial injury in a murine model of congestive heart failure induced by viral myocarditis.

The effects of Mu-Fang-Ji-Tang (TJ-36), a traditional Chinese herbal medicine, were studied in a murine model of congestive heart failure induced by viral myocarditis. In the group of animals treated with Mu-Fang-Ji-Tang in a dose of 1.5g/kg/day, the heart weight to body weight ratio was significantly lower than in the control group (p<0.01). Histopathological grades were also significantly lower in the Mu-Fang-Ji-Tang treated group than in the placebo group (p<0.05). Furthermore, survival was increased in the Mu-Fang-Ji-Tang treated group, versus the control group (p<0.05). In vitro, murine J774A.1 macrophages inoculated with encephalomyocarditis virus produced a significantly greater amount of nitrites compared to non-activated macrophages. Mu-Fang-Ji-Tang added to the cells (25, 50, 75, 100 microg/ml) concomitantly with the encephalomyocarditis virus inhibited nitrite formation in a concentration-dependent manner. Mu-Fang-Ji-Tang showed a protective effect against myocardial injury leading to congestive heart failure in this animal model.

Vinculin is an essential component for normal myofibrillar arrangement in fetal mouse cardiac myocytes.

Vinculin is a cytoskeletal protein that is believed to be an essential component in the linkage of cytoskeletal actin filaments to the plasma membrane. To investigate the precise function of vinculin in the development of cardiac myofibrils, antisense oligodeoxynucleotides complementary to vinculin mRNA were used to perturb the expression of the protein during myofibril assembly and arrangement in mouse cardiac myocytes. Fetal (day 18-20 post-conception) mouse cardiac myocytes were isolated by collagenase digestion, separated by Percoll density gradient centrifugation, and plated on aligned collagen gels. By 72 h of culture, mouse myocytes displayed an elongated in vivo-like phenotype in parallel with the aligned fibrils of the collagen gels with polarized arrays of myofibrils. Two different antisense oligonucleotides (20-mer) altered the formation of the tissue-like phenotype of myocytes. These antisense oligonucleotides suppressed vinculin protein expression at 43.5+/-26.8% and 48.7+/-20.9% when compared to myocytes that were not treated. Examination of these myocytes by confocal scanning laser and transmission electron microscopy revealed a disruption of the aligned in vivo-like phenotype, assembly of thick and thin filaments, and formulation of Z-bands. Random sequence 20-mer oligonucleotides used as controls had little detectable effect on vinculin protein expression (94.2+/-14.8%), cell shape, normal alignment or assembly of myofibrils. These results indicate that vinculin is a critical cytoskeletal component, that functions in the determination of cell shape and the arrangement and organization of developing myofibrils.

Prolongation of murine cardiac allograft survival with vesnarinone.

Vesnarinone is a non-glycoside positive inotropic drug that has immunomodulating actions. In the present study, the effects of vesnarinone on both cardiac allografts and lymphocytes were investigated. First, in a mouse model of primary vascularized heterotopic cardiac transplantation, the oral vesnarinone treatment at a dose of 50 mg/kg/day prolonged median graft survival time significantly as compared with the vehicle-treated control. Histopathological examination revealed that cellular infiltration and interstitial edema were less prominent in the vesnarinone-treated than in the vehicle-treated allografts. The plasma concentrations of vesnarinone in mice treated with a single dose of 50 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were performed. The generation of specific cytotoxic T lymphocytes in mixed lymphocyte culture was significantly suppressed by the treatment with vesnarinone, especially at 3 and 10 microg/ml. The production of interferon-gamma in the co-culture was also suppressed by 10 microg/ml vesnarinone. However, the level of cyclic adenosine monophosphate was not significantly affected by vesnarinone at 10 microg/ml. The results suggest that vesnarinone acts beneficially on rejecting cardiac allografts through its lymphocyte-suppressive property, although this property may not be closely associated with the inhibiting action of the drug on the cyclic adenosine monophosphate-phosphodiesterase enzyme.

Immunomodulation by an adenylate cyclase activator, NKH477, in vivo and vitro.

Cyclic adenosine monophosphate (cAMP) is an intracellular second messenger which modulates T cell function. NKH477 is a direct adenylate cyclase activator derived from forskolin and now under clinical investigation as a positive inotropic agent. While the immunosuppressive effects of forskolin on lymphocytes have been reported, little is known about its effects in vivo. In this study, we investigated whether NKH477 has immunosuppressive effects in mice, namely on cardiac allograft survival, and on the generation of cytotoxic T lymphocytes (CTL), T cell proliferation in mixed lymphocyte reaction (MLR), and production of interleukin-2 (IL-2) in MLR and in mitogen response. We assessed the effects of standard immunosuppressant cyclosporin A (CsA) on IL-2 production and on allograft survival to estimate the intensity of rejection in this acute rejection model. Saline-treated C57BL/6 (H-2b) mice rejected DBA/2 (H-2d) cardiac allografts with a median graft survival time of 10 days. In contrast, median graft survival was prolonged to 12 and 15 days in mice treated with NKH477 at 1 and 3 mg/kg/day, respectively (P < 0.01 vs control). The equivalent dose of CsA (40 mg/kg/day) to the maintenance dose after clinical cardiac transplantation prolonged median graft survival time to 15.5 days, indicating that high dose of NKH477 was as efficacious as lower dose of CsA. Addition of NKH477 to the culture medium suppressed the generation of CTL, T cell proliferation in MLR, and production of IL-2 in MLR and in mitogen response. These results suggest that NKH477 exerts a beneficial effect on murine cardiac allograft survival by modulating T cell function.

Angiotensin II receptor antagonist TCV-116 reduces graft coronary artery disease and preserves graft status in a murine model. A comparative study with captopril.

BACKGROUND: Despite the current progress in immunosuppressive regimens, the incidence of graft coronary artery disease (CAD) after cardiac transplantation has not decreased. Recent study has revealed that angiotensin-converting enzyme (ACE) inhibition decreases CAD in rats; however, it is not clear whether this beneficial effect of ACE inhibition is due to a decrease in production of angiotensin II (Ang II) or inhibition of bradykinin degradation. To determine whether Ang II type 1 receptor (AT1-R) blockade has an inhibitory effect on CAD, we evaluated the effects of TCV-116, an AT1-R antagonist, in a murine model of cardiac transplantation. METHODS AND RESULTS: Hearts of DBA/2 mice (H-2d) were transplanted heterotopically to B10.D2 mice (H-2d). Recipients were treated orally with TCV-116 (10 mg/kg per day), captopril (100 mg/kg per day), or vehicle only. Graft status, as assessed by palpation and inspection at laparotomy 70 days after transplantation, was preserved better in the TCV-116-treated group (P < .005) and in the captopril-treated group (P < .05) than in the vehicle-treated group. Intimal area in the graft coronary arterial wall decreased to 31% in the TCV-116-treated group (P < .001 versus vehicle-treated group) and to 34% (P < .005) in the captopril-treated group but was 45% in the vehicle-treated group. Fibrotic lesions of the left ventricle were less prominent in the TCV-116-treated (31%; P < .01 versus vehicle-treated group) and captopril-treated groups (33%; P < .05) than in the vehicle-treated group (54%). CONCLUSIONS: These findings show that AT1-R blockade is at least as effective as ACE inhibition in management of chronic allograft rejection and suggest that Ang II may play an important role in chronic allograft rejection.

Beneficial effect of amrinone on murine cardiac allograft survival.

Amrinone is a non-glycoside positive inotropic agent with an inhibitory effect on a cyclic adenosine monophosphate (AMP) phosphodiesterase isoenzyme. In the present study, we examined the immunosuppressive action of amrinone, since several other cyclic AMP-elevating agents have been shown to suppress T lymphocyte activation. First, the in vivo effects of amrinone were investigated. Oral amrinone treatment, at 40 mg/kg per day, significantly prolonged median cardiac allograft survival compared with non-treated controls (22.0 days versus 10.5 days, P < 0.01) when DBA/2 mouse hearts (H-2d) were heterotopically transplanted into C57B1/6 mice (H-2b). Histopathological examination showed that there was less prominent cellular infiltration in the amrinone-treated than in the non-treated allografts. Plasma amrinone concentrations of mice after a single oral dose of 40 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were done. The generation of specific cytotoxic T lymphocytes after mixed lymphocyte culture was significantly suppressed by addition of amrinone to the culture medium at 5 micrograms/ml. The production of IL-2 and the interferon-gamma during mixed lymphocyte culture was also suppressed by amrinone at 5 micrograms/ml. However, the level of intracellular cyclic AMP in mouse splenic lymphocytes was not affected significantly by the same dose of amrinone. In conclusion, amrinone has immunosuppressive actions at the therapeutic doses, and it may be a beneficial agent for therapy against acute cardiac allograft rejection.

Experimental graft coronary artery disease in a murine heterotopic cardiac transplant model.

BACKGROUND: The development of immunosuppressive therapy has brought about a remarkable decrease in the risk of acute cardiac allograft rejection; however, the major cause of patient death or retransplantation after the first postoperative year is coronary artery disease (CAD) in the graft. The pathogenesis and management of CAD are still not clearly established. METHODS AND RESULTS: To make an animal model of CAD, we performed primary vascularized heterotopic cardiac transplantation using mice. Inbred strains, sharing major histocompatibility antigens but differing in minor antigens, were selected. DBA/2 mice (H-2d) served as donors and B10.D2 mice (H-2d) as recipients. Viability of the cardiac grafts was assessed by abdominal palpation. Eight of twelve cardiac allografts (67%) survived for 10 weeks after operation without any immunosuppressive therapy. Allografts rejected within 4 weeks showed acute rejection histologically, whereas allografts surviving more than 4 weeks displayed intimal hyperplasia in the coronary arteries, together with interstitial and perivascular fibrosis. The severity of intimal thickening in the graft coronary artery was then assessed by point counting. In allografts surviving for 70 days, intima comprised approximately 42% of the graft arterial wall, whereas in DBA/2 and B10.D2 syngeneic grafts, it comprised approximately 13%. A significant difference in percentage was observed between the intima area of allografts and that of syngrafts (P < .01, ANOVA). Long-term oral administration of cyclosporine at a dose of 40 mg/kg per day decreased the intima area to 34% (P < .05 versus nontreated allografts, ANOVA); however, this dose did not affect the incidence of arterial lesions. CONCLUSIONS: The histopathological features of DBA/2 allografts surviving for 10 weeks in B10.D2 recipient mice mimicked those in human CAD. Using this animal model, the beneficial effect of low-dose cyclosporine therapy on CAD was demonstrated, although this effect seemed to be limited. This DBA/2-B10.D2 mouse heterotypic cardiac transplant model provides valuable results for future studies of the disease.

[Two-dimensional and Doppler echocardiographic findings of a sudden death case due to multiple pulmonary thromboses].

This is a case report presenting interesting findings on two-dimensional and Doppler echocardiograms due to multiple pulmonary thromboses. A 67-year-old woman had a history of surgery for colon polyps in August, 1986. After surgery, she suffered from tachycardia and dyspnea, and was admitted to our hospital because of a loss of consciousness. Sinus tachycardia, complete right bundle branch block and T-wave inversion in leads III, aVF and V1-4 were observed on her electrocardiogram. Cardiomegaly was noted on her chest radiograph. On the third hospital day, echocardiography was performed. On two-dimensional echocardiography, marked right ventricular dilatation with hypokinesis of the wall, and a flattened interventricular septum were observed on the short-axis view, and M-mode echocardiograms showed disappearance of the E wave and delay of the opening of the tricuspid valve, resulting in a monophasic triangular pattern. Doppler echocardiography showed the tricuspid valve flow to be delayed, mainly observed during atrial systole. These findings indicate decreased right ventricular compliance. The patient died on the 6th hospital day, and multiple new and old thrombi were found in the pulmonary artery at autopsy.