Hepatocellular carcinoma diagnosis using a novel electrochemiluminescence immunoassay targeting serum IgM-free AIM

BACKGROUND

Recent increases in the number of patients with non-alcoholic steatohepatitis (NASH) warrant the identification of biomarkers for early detection of hepatocellular carcinoma (HCC) associated with NASH (NASH-HCC). IgM-free apoptosis inhibitor of macrophage (AIM), which generally associates with IgM in blood and exerts its biological function by dissociation from IgM, may serve as an effective biomarker for NASH-HCC. Here, we established a fully automatic and high-throughput electrochemiluminescence immunoassay (ECLIA) to measure IgM-free AIM and investigated its efficacy in diagnosing NASH-HCC and viral HCC.

METHODS

IgM-free AIM levels were measured in 212 serum samples from patients with, or without, HCC related to NASH, hepatitis B virus, and hepatitis C virus, using ECLIA. We also developed an ECLIA for measuring both IgM-free and IgM-bound AIM and investigated the existing form of AIM in blood by size-exclusion chromatography.

RESULTS

IgM-free AIM levels were significantly higher in the HCC group than in the non-HCC group, regardless of the associated pathogenesis. Moreover, the area under the receiver operating curve for IgM-free AIM was greater than that for conventional HCC biomarkers, alpha-fetoprotein or des-γ-carboxy prothrombin, regardless of the cancer stage. ECLIA counts of IgM-free AIM derived from samples fractionated by size-exclusion chromatography were significantly higher in patients with NASH-HCC than in healthy volunteers and in patients with non-alcoholic fatty liver and NASH.

CONCLUSIONS

Serum IgM-free AIM may represent a universal HCC diagnostic marker superior to alpha-fetoprotein or des-γ-carboxy prothrombin. Our newly established ECLIA could contribute to further clinical studies on AIM and in vitro HCC diagnosis.

Activation of apoptosis inhibitor of macrophage is a sensitive diagnostic marker for NASH-associated hepatocellular carcinoma

BACKGROUND

A diagnostic marker is needed enabling early and specific diagnosis of hepatocellular carcinoma (HCC) associated with non-alcoholic steatohepatitis (NASH). Our recent findings have indicated that circulating apoptosis inhibitor of macrophage (AIM), which usually associates with IgM pentamer in the blood, is activated by its dissociation from IgM. We investigated the serum levels of IgM-free AIM for AIM activation and its possible relationship with development of HCC in NASH.

METHODS

Serum levels of IgM-associated and IgM-free AIM were evaluated in patients with non-alcoholic fatty liver, NASH, and NASH-HCC using enzyme-linked immunosorbent assays and immunoblots. Liver biopsy specimens were graded and staged using Brunt's classification.

RESULTS

Forty-two patients with fatty liver, 141 with NASH, and 26 with NASH-HCC were evaluated. Patients with stage 4 or grade 3 NASH (with or without HCC) exhibited significantly higher levels of both IgM-free and total AIM than those with fatty liver, whereas the ratio of IgM-free-to-total AIM was equivalent in these groups. Among patients with the same fibrosis stage of NASH, those with HCC had significantly higher IgM-free but not total AIM levels, resulting in a proportional increase in the IgM-free/total AIM ratio. Analysis of the areas under the receiver operating characteristic curves indicated the high sensitivity of the IgM-free AIM for NASH-HCC.

CONCLUSIONS

Our observations suggest the activation of AIM in blood in the presence of NASH-HCC, with a significant increase in IgM-free AIM levels. IgM-free AIM serum levels appear to be a sensitive diagnostic marker for NASH-HCC.

Variation in antigen-antibody affinity among serotypes of Salmonella O4 serogroup, determined using specific antisera

Serotyping is widely used for typing Salmonella during surveillance, and depends on determining the lipopolysaccharide (LPS) O-antigen and the flagellar protein (H-antigens) components. As the O-antigen is highly variable, and structurally unique to each serotype, we investigated the binding affinities of LPS from Salmonella serotypes of O4 serogroup with specific anti-antigen serum via immunoblot and enzyme-linked immunosorbent assays. Since the serotypes from O4 serogroup also express the O-antigen factor 12, O12 antiserum was also used for the analysis. LPS from the different serotypes showed different binding affinities with the antisera. Therefore, based on the antigen-antibody affinity, a modified agglutination assay was carried out by using O4 and O12 antisera. Although serotypes from O4 serogroup have the common O-antigen factors 4 and 12, the analysis showed that the degree of agglutination reaction is different for each of the serotypes. We suggest that Salmonella serogroup O4 serotypes exhibit different binding affinities with specific antisera despite the presence of common O-antigen factors 4 and 12.

Monoclonal antibody-based competitive enzyme-linked immunosorbent assay to detect antibodies to O:4 Salmonella in the sera of livestock and poultry

Serotyping is an important element for surveillance of Salmonella. In this study, an anti-O:4 Salmonella monoclonal antibody-based competitive enzyme-linked immunosorbent assay that could identify Salmonella infection in cow, pig, horse, and chicken was developed. This detection system can therefore be useful for a wide range of animals and for humans.

Application of West Nile virus diagnostic techniques

West Nile virus (WNV) is an enveloped RNA virus in the family Flaviviridae and belongs to Japanese encephalitis virus serocomplex group. The WNV has a wide geographic distribution that includes Africa, Europe, Asia, America and Australia. Recently, it has re-emerged as an important pathogenic organism, illustrated by the series of WNV outbreaks in North America and in Europe. Several hundred people are sacrificed by WNV infection every year. WNV can infect many mammals, birds, reptiles and amphibians. A variety of diagnoses for WNV infection have been developed, such as virus isolation, nucleotide amplification, antigen detection and serology. Flaviviruses, including WNV, share common nucleotide sequences and antigenic epitopes. Understanding these properties that can influence cross-reactivity is important for accurate diagnosis, especially because areas with multiple flaviviruses are currently expanding. Herein, the authors outline the different diagnostic methods for detecting WNV infection as well as important considerations in using these methods.

A rapid differentiation method for enteroinvasive Escherichia coli

Enteroinvasive Escherichia coli (EIEC) comprise 21 major serotypes defined by the presence of O and H antigens, and diagnosis depends on determining its invasive potential. Using HEp-2 cells infected with an EIEC strain, we developed a simple growth-dependent assay that differentiated EIEC strain from non-invasive strains 6 h after infection.

Expression and characterization of bluetongue virus serotype 21 VP7 antigen: C-terminal truncated protein has significantly reduced antigenicity

In the present study, group-specific antigen VP7 of bluetongue virus (BTV) serotype 21 isolated from cattle in Tochigi prefecture in Japan in 1994 was characterized by sequencing and expression. Gene was amplified from cDNA synthesized on viral dsRNA using reverse-transcriptase-PCR. Nucleotide sequence of this isolate showed high similarity with other published BTV VP7 sequences. Full-length and C-terminal truncated forms of VP7 were expressed in insect cells by a baculovirus gene expression system under control of the viral polyhedrin promoter. Expression of full-length recombinant VP7 was confirmed by immunoprecipitation with VP7 specific monoclonal antibody (8A3B.6, ATCC). Recombinant proteins expressed with or without 6x His-tag showed good expression levels in TN5 cells and reacted well with the monoclonal antibody in the indirect ELISA. However C-terminal truncated VP7 with His-tag failed to react with this monoclonal antibody, while poor antigenicity was evident when it was reacted with infected bovine serum. Reduced antigenicity of the latter suggested that C-terminal truncation affects 8A3B.6 epitope construction probably via inhibition of VP7 trimer structure formation.

[Scimitar syndrome; report of a case]

A 17-year-old woman with scimitar syndrome without an atrial septal defect was operated by intra-cardiac conduit repair. Computed tomography (CT) and magnetic resonance imaging (MRI) showed resolution images of anatomical findings of scimitar vein. Surgical procedures for the scimitar syndrome have varied according to the anatomic features presented in each case. The detection of precise anatomy of scimitar syndrome is important for determining the appropriate surgical procedure. Images of 3-dimensional (3-D) CT and MRI of scimitar syndrome were demonstrated.

Newly developed left main coronary artery lesion after coronary stenting

Percutaneous transluminal coronary stenting is a proven nonoperative method of direct myocardial revascularization. We encountered a case of iatrogenic significant subacute left main coronary artery stenosis in a patient who had undergone prior percutaneous transluminal coronary artery stenting of the left anterior descending (LAD) artery. Coronary artery bypass grafting was performed. To our knowledge, this is the first report of a surgical case of left main coronary artery stenosis worsened by changes secondary to earlier coronary stenting in the mid portion of left descending coronary artery in Japan.

[A case of protruding atherosclerotic plaque with mobile projections in the sino-tubular junction]

A 66-year-old woman who received maintenance hemodialysis for the last 14 years was referred to our hospital due to the sudden onset of ischemic stroke and systemic emboli. Transthoracic echocardiography before surgery showed large protruding masses measuring 2 cm which projected into the lumen of the aortic root. The plaque originated on a wide base of the posterior aspect of the ascending aorta at its junction with the sinus of Valsalva. The mobile plaque was surgically removed by endarterectomy from the posterior wall of sino-tubular junction under cardiopulmonary bypass. Pathologic examination of the masses removed at the time of surgery showed that they were atherosclerotic plaque with superimposed thrombi. During operation, transesophageal echocardiography appears to be useful for the rapid detection of a protruding aortic atheroma especially in the initial period of cardiopulmonary bypass until aortic cross clamp.

Recurrent aortic valve endocarditis caused by Gemella morbillorum--report of a case and review of the literature

Gemella morbillorum (G. morbillorum) is part of the commensal flora of the oropharynx and intestinal tract, and on rare occasions causes infective endocarditis. A 55-year-old man with massive aortic regurgitation caused by recurrent infective endocarditis with G. morbillorum had a history of prior endocarditis caused by alpha-hemolytic streptococcus and multiple antibiotic allergies 5 years prior, and was successfully treated by aortic valve replacement. Almost all the reported cases of endocarditis caused by G. morbillorum have been bacteriologically cured with antibiotics and this is the first reported case of recurrent endocarditis caused by G. morbillorum in which the initial infection was bacteriologically cured by antibiotics and the secondary infection treated with valve replacement. This organism can be one of the causes of infective endocarditis and prompt surgical repair is mandatory if the infection is refractory or there is progression of congestive heart failure under antibiotic cover.

[Surgical treatment for aortic aneurysms associated with coronary artery disease-selection of bypass conduit]

Graft replacement for arch aneurysms and concomitant coronary artery bypass grafting (CABG) were performed in four consecutive patients over a three-year period between March 1995 and October 1998. The etiology of the aneurysms was atherosclerosis in all the patients. One early death as a result of a cerebellar infarction occurred on the 74th postoperative day. In all cases, respiratory failure frequently occurred after surgery. In a recent case, the internal mammary artery was used as a graft conduit to the left anterior descending artery (LAD). Both artery and vein grafts were anastomosed to coronary arteries during the initial core cooling. Selective cerebral perfusion was carried out during the reconstruction of the transverse aortic arch and its branches. The left subclavian artery was anastomosed first to secure perfusion to the LAD. To achieve sufficient myocardial protection and obtain good postoperative hemodynamics, CABG was simultaneously performed at the time of aortic aneurysm repair in cases complicated with coronary artery disease.

[Surgical treatment for chronic pulmonary thromboembolism in a patient with protein C deficiency]

Medical therapy for chronic pulmonary thromboembolism is limited, and surgical treatment has become more frequent recently. We have performed pulmonary thromboendarterectomy on a patient with chronic pulmonary thromboembolism accompanied by protein C deficiency. The patient was a woman aged 68 years who had protein C deficiency. The preoperative condition was New York Heart Association functional class IV. Hypoxemia, marked pulmonary hypertension, and low cardiac output were observed. After a median sternotomy, moderate hypothermia was induced using a cardiopulmonary bypass, and thromboendarterectomy in the pulmonary artery was performed. The arterial blood oxygen concentration improved, and the mean pulmonary pressure decreased. The cardiac output also increased, and New York Heart Association functional class improved to I. Pulmonary thromboendarterectomy under cardiopulmonary bypass was effective for chronic pulmonary thromboembolism accompanied by protein C deficiency.

Papillary fibroelastoma in association with thrombosis on a mechanical valve

A patient with a thrombosed mechanical valve underwent valve re-replacement during which a tumor of the left ventricular outflow tract with the typical macroscopic and microscopic characteristics of a papillary fibroelastoma was successfully removed surgically. The 60-year-old woman had undergone isolated mitral valve replacement with a St Jude Medical 29-mm valve for mitral regurgitation 15 years ago. The present admission was for investigation of dyspnea on exertion. Two-dimensional transthoracic echocardiography demonstrated a posteroseptal, pedunculated mass, measuring 1.3x1.0 cm, in the outflow tract of the left ventricle, mild mitral regurgitation and slight aortic stenosis.

The release of nitroglycerin absorbed into the central venous catheter

This study was conducted to evaluate the release of nitroglycerin (NG) that has been absorbed into the central venous catheter. A 0.05% NG solution was infused through a central venous catheter and the flow rates were set at 1, 5, or 10 ml/h, given over 12, 24, or 48 h. The catheter was flushed with lactate Ringer solution after completion of the NG infusion. The elution of the lactate Ringer solution from the tip of the catheter was then collected and assayed for its NG concentration by high performance liquid chromatography (HPLC). A higher concentration of NG was released with a faster flow rate and a longer infusion. The high level of NG release continued during the first 20 min, and ranged from a minimum of 0.07 mg/ml to a maximum that exceeded 0.15 mg/ml. Subsequently, the NG concentration gradually declined, but low concentrations of 0.006-0.02 mg/ml were still maintained 360 min later. Thus, it is suggested that if a catheter such as the Swan-Ganz continues to be used after the completion of a NG infusion, certain pharmacological effects due to the absorption of NG into the catheter body should be expected for at least 60 min.

Sudden deterioration of aortic regurgitation due to rupture of a raphal cord on the conjoined cusp

A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.

Inositol 1,4,5-trisphosphate receptor type 1 is a substrate for caspase-3 and is cleaved during apoptosis in a caspase-3-dependent manner

The inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R), an IP(3)-gated Ca(2+) channel located on intracellular Ca(2+) stores, modulates intracellular Ca(2+) signaling. During apoptosis of the human T-cell line, Jurkat cells, as induced by staurosporine or Fas ligation, IP(3)R type 1 (IP(3)R1) was found to be cleaved. IP(3)R1 degradation during apoptosis was inhibited by pretreatment of Jurkat cells with the caspase-3 (-like protease) inhibitor, Ac-DEVD-CHO, and the caspases inhibitor, z-VAD-CH(2)DCB but not by the caspase-1 (-like protease) inhibitor, Ac-YVAD-CHO, suggesting that IP(3)R1 was cleaved by a caspase-3 (-like) protease. The recombinant caspase-3 cleaved IP(3)R1 in vitro to produce a fragmentation pattern consistent with that seen in Jurkat cells undergoing apoptosis. N-terminal amino acid sequencing revealed that the major cleavage site is (1888)DEVD*(1892)R (mouse IP(3)R1), which involves consensus sequence for caspase-3 cleavage (DEVD). To determine whether IP(3)R1 is cleaved by caspase-3 or is proteolyzed in its absence by other caspases, we examined the cleavage of IP(3)R1 during apoptosis in the MCF-7 breast carcinoma cell line, which has genetically lost caspase-3. Tumor necrosis factor-alpha- or staurosporine-induced apoptosis in caspase-3-deficient MCF-7 cells failed to demonstrate cleavage of IP(3)R1. In contrast, MCF-7/Casp-3 cells stably expressing caspase-3 showed IP(3)R1 degradation upon apoptotic stimuli. Therefore IP(3)R1 is a newly identified caspase-3 substrate, and caspase-3 is essential for the cleavage of IP(3)R1 during apoptosis. This cleavage resulted in a decrease in the channel activity as IP(3)R1 was digested, indicating that caspase-3 inactivates IP(3)R1 channel functions.

Unusual complications in an inflammatory abdominal aortic aneurysm

An unusual case of an inflammatory abdominal aortic aneurysm (IAAA) associated with coronary aneurysms and pathological fracture of the adjacent lumbar vertebrae. The associated coronary lesions in cases of IAAA are usually occlusions. In the present case, it was concluded that a possible cause of the coronary aneurysm was coronary arteritis and the etiology of the pathological fracture of the lumbar vertebrae was occlusion of the lumbar penetrating arteries due to vasculitis resulting in aseptic necrosis. Inflammatory AAA can be associated with aneurysms in addition to occlusive disease in systemic arteries. The preoperative evaluation of systemic arterial lesions and the function of systemic organs is essential.

Bleeding through the fiber interstices of a knitted dacron graft 12 years after its implantation: report of a case

We present herein the case of a 65-year-old man who suddenly developed fresh perigraft bleeding into the space between a knitted Dacron bifurcated graft and the aneurysmal sac, 12 years after undergoing graft replacement. Intraoperative findings did not show Dacron fiber degeneration at the nonanastomotic sites or a pseudoaneurysm at the anastomotic site. Widened Dacron fiber interstices resulting from graft dilation without sufficient graft healing was thought to have caused delayed hemorrhage through the macroscopically intact graft material, followed by massive clot retention between the graft and the aneurysmal sac. This case report serves to demonstrate that careful long-term follow-up is essential for patients who have undergone vascular graft replacement.

Calmodulin inhibits inositol 1,4,5-trisphosphate-induced calcium release through the purified and reconstituted inositol 1,4,5-trisphosphate receptor type 1

Our previous studies have demonstrated that calmodulin binds to IP3R type I (IP3R1) in a Ca2+ dependent manner, which suggests that calmodulin regulates the IP3R1 channel. In the present study, we investigated real-time kinetics of interactions between calmodulin and IP3R1 as well as effects of calmodulin on IP3-induced Ca2+ release by purified and reconstituted IP3R1. Kinetic analysis revealed that calmodulin binds to IP3R1 in a Ca2+ dependent manner and that both association and dissociation phase consist of two components with time constants of k(a) = 4.46 x 10(2) and > 10(4) M(-1) s(-1) k(d) = 1.44 x 10(-2) and 1.17 x 10(-1) s(-1). The apparent dissociation constant was calculated to be 27.3 microM. The IP3-induced Ca2+ release through the purified and reconstituted IP3R1 was inhibited by Ca2+/calmodulin, in a dose dependent manner. We interpret our findings to mean that calmodulin binds to IP3R1 in a Ca2+ dependent manner to exert inhibitory effect on IP3R channel activity. This event may be one of the mechanisms governing the negative feedback regulation of IP3-induced Ca2+ release by Ca2+.

Calmodulin mediates calcium-dependent inactivation of the cerebellar type 1 inositol 1,4,5-trisphosphate receptor

The dependency of purified mouse cerebellar type 1 inositol 1,4,5-trisphosphate receptor (IP3R1)/Ca2+ channel function on cytoplasmic Ca2+ was examined. In contrast to the channels in crude systems, the purified IP3R1 reconstituted into planar lipid bilayers did not show the bell-shaped dependence on Ca2+. It was activated with increasing Ca2+ sublinearly without inhibition even up to 200 microM. The addition of calmodulin to the cytoplasmic side inhibited the channel at high Ca2+ concentrations. Calmodulin antagonists reversed the Ca2+-dependent inactivation of the native channels in cerebellar microsomes. These results indicate that the bell-shaped dependence on cytoplasmic Ca2+ is not an intrinsic property of the IP3R1, and the Ca2+-dependent inactivation is directly mediated by calmodulin.

Real time analysis of interaction between inositol 1,4, 5-trisphosphate receptor type I and its ligand

Inositol 1,4,5-trisphosphate (IP(3)) is an important second messenger that releases intracellular Ca(2+) by binding to its specific receptor, inositol 1,4,5-trisphosphate receptor (IP(3)R), in a wide range of cellular processes. We report here large-scale expression and purification of N-terminal 604 amino acids of IP(3)R type 1 (T604) expressed in E. coli, which contains the ligand binding domain. Surface plasmon resonance biosensor studies showed that purified T604 could bind to its ligands with binding specificity identical to that of full-length native IP(3)R type 1. Kinetic parameters of T604 for IP(3) consisted of a fast association rate constant (K(ass) = 1.2 x 10(6) M(-1) s(-1)) and a rapid dissociation rate constant (k(diss) = 1 s(-1)), and the equilibrium dissociation constant was determined to be 336 nM, at 150 mM NaCl and pH 7.4. However, association and dissociation patterns depended on the pH level and ionic strength. These results pave the way toward detail analysis of structure-function analysis of the ligand binding domain of IP(3)R type 1 for its ligands.

A double bifurcated graft for abdominal aorta and bilateral iliac artery reconstruction

Revascularization of the hypogastric artery often tends to be neglected in aortoiliac reconstructive surgery; however, its incomplete revascularization can result in unfavorable complications such as buttock claudication or necrosis, vascular impotence, and colonic ischemia. Multiple vascular lesions in the abdominal aorta and bilateral iliac arteries were reconstructed using a newly designed double bifurcated graft in five male patients. All five patients demonstrated excellent graft limb patency and postoperative improvement of the ankle-brachial pressure index without any clinical signs of ischemia in regions of the hypogastric artery. Thus, we conclude that an aggressive approach toward hypogastric circulation maintenance is essential in aortoiliac reconstructive surgery. By using this double bifurcated graft, rapid and safe revascularization of the bilateral hypogastric arteries concomitant with the external iliac or femoral arteries can be performed.

Evaluation of effect and distribution of heparin administered in vascular reconstructive surgery

BACKGROUND

The aim of this study was to find out whether intravenously administered heparin is distributed equally not only proximal but also distal to the arterial occlusion level in vascular reconstructive surgery.

METHODS

Ten consecutive patients (7 men and 3 women) with an average age of 69.9 years (range, 51 to 76 years) who underwent graft replacement for aortic abdominal aneurysm from April to December 1994 were studied. Mean aortic clamp time was 76 minutes. Heparin sodium (100 U/kg) was administered intravenously to keep activated clotting time (ACT) over 250 secs and was neutralized by protamine sulfate (1 mg/kg) just after reperfusion. ACT, blood lactate and CPK-MM in the brachial and dorsal pedis artery were measured before heparin administration (control), just after arterial occlusion, just before reperfusion and 10 minutes after protamine administration.

RESULTS

ACT was significantly prolonged after arterial occlusion and recovered after protamine administration with no significant differences between proximal and distal values at each point. Lactate showed significant increase after arterial occlusion which was more remarkable distally. CPK-MM was all the way within the normal range.

CONCLUSIONS

In vascular reconstructive surgery which requires temporary arterial occlusion for as long as 80 minutes, the effect of heparin is excellent and equal throughout the body by collateral vessels, and the metabolic influence due to blockade of the blood flow is not so critical as to lead to cellular damage although anaerobic glycolysis is promoted distally due to hypoxia.

Cardiopulmonary bypass established via a sutured vascular graft in the presence of extraanatomic bypass

Cardiopulmonary bypass (CPB) was established via a sutured collagen sealed knitted Dacron graft in two patients who had undergone extraanatomic bypasses for lower limb ischemia, whose ascending aorta was not suitable for cannulation. One patient, with a history of femorofemoral bypass, underwent surgery for a ruptured aortic arch aneurysm (AAA) and the other patient, with a history of axillobifemoral bypass for chronic dissection involving the aortic arch and descending aorta, had unstable angina and underwent coronary artery bypass grafting. This technique of perfusion was found to be safe and effective for patients with an impaired ascending aorta who have undergone an extraanatomic bypass for the lower limb.

A case of ruptured descending thoracic aortic aneurysm into the right pleural cavity: importance of preoperative drainage of the right pleural cavity

We present an unusual case of a ruptured descending thoracic aortic aneurysm into the right pleural cavity of a patient with pectus carinatum. The presence of pectus carinatum played an important role in the development of the aneurysm at the atypical site and the rupture into the right pleural cavity. A small amount of right pleural bleeding on admission can increase and develop to massive hemothorax until emergency operation. Massive bleeding in the right pleural cavity where the dependent lung is located causes atelectasis and increased shunt fraction under one lung ventilation. Therefore, continuous drainage of the right pleural cavity is essential to prevent serious hypoxia during graft replacement in a case of ruptured descending thoracic aneurysm into the right hemithorax.

[A successful repair of infective endocarditis accompanied by a pseudoaneurysm of the left ventricle]

The present paper reports a successful surgical treatment of a 47-year-old male with a pseudoaneurysm of the left ventricle. The patient has also been administered Penicillin G for 5 months to treat endocarditis. Cardiac catheterization showed severe aortic stenosis and a pseudoaneurysm of the left ventricle which was dilating in systole. The patient underwent patch closure of the pseudoaneurysm whose ostium was situated at the miral-aortic inter valvular fibrosa followed by aortic valve replacement and direct closure of a right Valsalva sinus aneurysm. His postoperative course was uneventful. The patient had no recurrence of endocarditis nor malfunction of the prosthetic valve for one year postsurgery. This is the first report in Japan of successful surgical treatment of a pseudoaneurysm of the left ventricle due to perforation of the miral-aortic intervalvular fibrosa after endocarditis.

Massive aortic regurgitation by spontaneous rupture of a fibrous strand in a fenestrated aortic valve

A very rare case of Marfan syndrome associated with acute aortic regurgitation due to rupture of a fibrous strand of a fenestrated aortic valve is presented. Although an aortic valve fenestration usually has no pathologic significance, its association with aortic annular dilatation plays an important role. Rupture of a myxomatously degenerated fibrous strand loaded with high tension from annular dilatation reducing the coaptation area of each cusp during diastole was the suspected cause of acute massive regurgitation by complete retroversion of the right coronary cusp. Rupture of a fibrous strand of a fenestrated aortic valve with a dilated annulus could result in acute massive aortic regurgitation, for which prompt surgical repair is mandatory.

Minimally invasive cardiac surgery in the adult: surgical instruments, equipment, and techniques

To clarify the special instruments and equipment used for minimally invasive cardiac surgery (MICS), we examined the initial experiences with MICS operations with ministernotomy or minithoracotomy at our institution. Fifty adult patients with congenital, valvular, and/or ischemic heart diseases underwent MICS operations, and all surgical procedures were completed without conversion to full sternotomy. The length of the skin incision was about 10 cm or less in all patients. Postoperative recovery was favorable, and the majority of the patients were discharged from the hospital around the end of the second postoperative week. In this series of patients, an oscillating bone saw, lifting type retractor, 2 blade spreader, cannula with a balloon, and right-angled aortic clamp among other items, were very useful for successfully performing various operations with MICS approaches and techniques. The associated results suggest that MICS with ministernotomy or minithoracotomy was feasible using special instruments and equipment and could be encouraged for adult patients with various cardiovascular diseases.

T-cell-receptor signalling in inositol 1,4,5-trisphosphate receptor (IP3R) type-1-deficient mice: is IP3R type 1 essential for T-cell-receptor signalling?

Stimulation of T-cells via the T-cell receptor (TCR) complex is accompanied by an increase in intracellular Ca2+ concentration ([Ca2+]i). Recently, it was reported that a stable transformant of the human T-cell line, Jurkat, expressing an antisense cDNA construct of inositol 1,4,5-trisphosphate receptor (IP3R) type 1 (IP3R1), failed to demonstrate increased [Ca2+]i or interleukin-2 production after TCR stimulation and was also resistant to apoptotic stimuli. This cell line lacked IP3R1 expression, but expressed the type-2 and -3 receptors, IP3R2 and IP3R3 respectively [Jayaraman, Ondriasova, Ondrias, Harnick and Marks (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 6007-6011, and Jayaraman and Marks (1997) Mol. Cell. Biol. 17, 3005-3012]. The authors concluded that IP3R1 is essential for TCR signalling and suggested that Ca2+ release via IP3R1 is a critical mediator of apoptosis. To establish whether a loss of IP3R1 function in T-cells occurred in vivo and in vitro, we investigated Ca2+ signalling after TCR stimulation and the properties of T-cells using IP3R1-deficient (IP3R1-/-) mice. As IP3R1-/- mice die at weaning, we transplanted bone marrow cells of IP3R1-/- mice into irradiated wild-type mice. Western blot analysis showed that the recipient IP3R1-containing (IP3R1+/+) lymphocytes were replaced by the donor IP3R1-/- lymphocytes after transplantation and that expression of IP3R2 and IP3R3 was unaltered. In contrast with the previous reports, T-cells lacking IP3R1 were able to mobilize Ca2+ from intracellular Ca2+ stores after stimulation via the TCR. We observed no significant differences between IP3R1+/+ and IP3R1-/- T-cells in terms of the number of thymocytes and splenocytes, the proportion of the T-cell phenotype, proliferative response to anti-CD3 monoclonal antibody (mAb) stimulation and cell viability. Therefore IP3R1 is not essential for T-cell development and function.

Primary aortoenteric fistula with a chronic isolated abdominal aortic dissection: report of a case

A 47-year-old woman on long-term hemodialysis due to a chronic isolated abdominal aortic dissection was admitted to our department with severe abdominal pain. She had not suffered any hematemesis or melena. An emergency laparotomy revealed an abdominal aortic aneurysm with a diameter of 60mm, densely adhered to the ileum. An aortoenteric fistula manifesting as intramural rupture into the ileum was found after infrarenal abdominal aortic and bilateral common iliac cross-clamping. The fistula on the ileac side was nontransmural, but that on the aortic side communicated with the pseudolumen of the abdominal aorta, and contained mural thrombus. The infrarenal abdominal aorta and bilateral common iliac arteries were replaced with a collagen-sealed woven Dacron bifurcated graft. Histological examination of the ileum in this portion showed intramural bleeding and xanthomatous granulation with foam cell infiltration in the thickened subserosa. While it is difficult to diagnose nonpenetrating aortoenteric fistula preoperatively, such a fistula must be considered in a patient with severe abdominal pain, for whom previous abdominal aortic surgery has been performed or when an abdominal aneurysm is observed. To our knowledge, no other case of an aortoenteric fistula presenting as an intramural rupture into the ileum in an isolated abdominal aortic dissection has ever been reported.

Multivarious clinical manifestations of multiple pseudoaneurysms in Behçet's disease

In Behçet's disease, an aneurysm is prone to progress rapidly to a pseudoaneurysm. Acute limb ischemia due to acute thrombosis of a femoral pseudoaneurysm and subsequent Horner's syndrome due to another subclavian pseudoaneurysm are very rare but acceptable complications in Behçet's disease. We present a case of Behçet's disease with multiple pseudoaneurysms, which also showed these other clinical manifestations. Over a short time span, the patient rapidly developed left femoral and right subclavian pseudoaneurysms, which were successfully resected with graft replacements.

[Coronary artery bypass grafting to the left circumflex artery in the atrioventricular groove]

Coronary artery bypass graftings were performed to the left circumflex artery (LCX) system in the atrioventricular groove (#11 or #13) in addition to revascularization to the left anterior descending artery system using conventional technique in 10 patients with left main trunk lesion. Distal anastomosis was done at #11 of LCX in 6 patients using saphenous vein graft, and at #13 of LCX in 4 patients using 2 saphenous vein grafts and using 2 internal thoracic artery grafts. The mean flow rate of SVG operated by this technique showed larger values than that of SVGs by sequential bypass or individual bypass technique to #12 and/or #14 of LCX. Postoperative angiographies showed excellent graft patencies and symptomatic improvements were achieved. This technique of coronary artery revascularization is recommended and useful in patients whose #12 and #14 of LCX system is too small to make distal anastomosis.

[A successful surgical treatment for huge left circumflex artery-right ventricle fistula using the fistula occlusion test]

A surgical case of rare coronary artery fistula between the left circumflex artery and right ventricle was reported. A 46-year-old woman had suffered from exertional dyspnea and palpitation for three years. Pan systolic heart murmur was heard through the left 4th inter costal space. The chest X-ray film demonstrated cardiac enlargement and lung congestion, and the electrocardiograms showed atrial fibrillation and left ventricular hypertrophy when she was admitted to our hospital. Preoperative catheterization revealed a huge coronary artery fistula originating from the left circumflex artery and opening into the right ventricle through the posterior wall of the heart. The left-to-right shunt ratio was 60% and Qp/Qs was 2.47. At operation, the dilated circumflex artery fistula was carefully dissected and the tape was passed around the fistula as a tourniquet under extra corporeal circulation on the beating heart. To estimate myocardial ischemia, the fistula occlusion test was performed by tightening the previously placed tourniquet. Monitoring of electrocardiograms, transesophageal echocardiography, and hemodynamics were useful to detect myocardial ischemia. The occlusion test was performed under ECC for 5 minutes. No ischemic changes were observed. The fistula was interrupted under cardiac arrest at the point of the occlusion test.

[One stage operation for sternal turnover with preserved rectus muscle pedicles and aortic root replacement associated with Marfan's syndrome]

A 40-year-old man with Marfan's syndrome had annulo aortic ectasia with Sellers grade 4 aortic valve regurgitation and Wada grade 3 pectus excavatum. Simultaneous operation was successfully performed by aortic valve composite graft insertion and sternal turnover with the rectus muscle pedicles. Following a midline skin incision, the cost-sterno complex (plastron) was dissected together with the bilateral rectus muscle pedicles, and the sternum was divided transversely through the second intercostal space. The plastron with muscle pedicles was retracted away from the anterior chest toward the abdomen and was covered by the moistened sternal bag made of polyethylene to prevent dryness and contamination during the composite graft insertion. The aortic root was replaced with a composite graft consisting of a 25 mm SJM valve and a 26 mm Hemashield graft. A short interposed 10 mm Hemashield graft was inserted between the ostia of the left coronary artery and the composite graft. The right coronary artery was reimplanted in the aortic conduit using the button technique with a doughnut pledget. This one stage method offered excellent operative exposure and enabled us to prevent possible necrosis of the sternum, infection of the mediastinal sinus, and postoperative cardiac failure resulting from chest wall compression. In this procedure, active usage of the rapid autologous transfusion system effectively reduced the total amount of blood transfusion.

[The leaflet fracture of a 19 mm SJM (HP) valve during valve insertion to the calcified small aortic annulus]

Aortic valve replacement was undergone in a 70-year-old woman with calcified aortic stenosis. Calcified and fused tricuspid aortic valve was excised and a 21 mm sizer passed with some difficulty through the annulus. A 19 mm SJM HP serious was selected and the horizontal mattress suturing technique was used. The valve was held at the cuff near the hinge guard and seated into the annulus by the usual amount of pressure, however, one leaflet fracture was retrieved and the valve was removed. A 19 mm standard SJM valve was then successfully implanted. The potential factors of leaflet fracture suggested that the leaflet thickness of smaller sized SJM valves showed smaller values than other bileaflet valves in the same sized-valves. In addition, the SJM valve does not have an orifice stiffening ring like other bileaflet valves. So, needless to say direct pressure to the leaflet, indirect pressure might cause valve destruction during insertion. The abnormal pressure applied to the direction from one hinge guard to the other can introduce deforming of the orifice ring resulting in leaflet fracture like this case. The pressure directed to the perpendicular direction may introduce leaflet escape due to the deforming of the valve orifice.

[Reconstructive surgery for head and neck cancers under multiple facility cooperation system]

The problems with the system for reconstructive surgery for head and neck cancers in our department where plastic surgeons are regularly invited from distant facilities were discussed. Especially, the importance of preoperative discussion between the plastic surgeons and ENT doctors was stressed. The computer system with Internet will play an important role in exchanging information such as CT scans and MRI scans between the plastic surgeons and ENT doctors. Moreover, the establishment of a system to prevent postoperative troubles such as closure of anastomosed vessels was stressed. Twenty-seven re-vascularized free flaps had been transferred with a 96.3% success rate (26 of 27 cases). We concluded that the system for reconstructive surgery under the multiple facility cooperation system worked well.

Thrombotic obstruction of a reinforced ringed expanded polytetrafluoroethylene graft caused by formation of a pseudoaneurysm at a nonanastomotic site: report of a case

We report herein the case of a 72-year-old man in whom a nonanastomotic pseudoaneurysm arose from a reinforced ringed expanded polytetrafluoroethylene (EPTFE) graft (Gore-Tex, Flagstaff, AZ, USA) following an axillobifemoral bypass. The pseudoaneurysm developed 2 years after graft insertion and induced graft thrombosis. The development of the pseudoaneurysm can be attributed to the fact that his axillobifemoral bypass graft was so short it deformed the proximal anastomosis, and the graft was subcutaneously tunneled onto the major pectoral muscle. These technical errors placed the graft under too much tension in the longitudinal direction, which resulted in graft disruption and pseudoaneurysmal formation, followed by thrombosis of the axillary artery. Moreover, the possibility of direct trauma at the time of insertion cannot be substantiated. Although the very poor compliance and design of the externally supported ring could not tolerate stretch deformity in the Gore-Tex graft, only one other case of a nonanastomotic pseudoaneurysm has ever been reported.