[Bentall Procedure and Total Arch Replacement with an Open Stentgraft after Ascending Aortic Replacement for Acute Type A Aortic Dissection].

A 40-year-old man underwent ascending aortic replacement for acute type A aortic dissection. Eight years later, Bentall procedure and total arch replacement with an open stentgraft (OSG) were performed due to enlargement of the aortic root and distal arch dissection as well as exacerbation of aortic valve incompetence. The computed tomography(CT) taken at 22 months postoperatively showed better stentgraft expansion than that immediately after the operation, reduction in the diameter of the distal aortic arch, and thrombosis of the false lumen from the aortic arch to the entire descending aorta. However, the CT taken at 33 months postoperatively revealed a new entry to the distal end of the stentgraft and blood flow in the false lumen. Although OSG is useful for extensive aortic aneurysm, strict follow-up is necessary in OSG for aortic dissection.

Aortopulmonary fistula caused by penetrating atherosclerotic ulcer and intramural hematoma.

A 75-year-old woman presented with chronic cough and hemoptysis. Chest computed tomography (CT) and aortography revealed a small, contrast-filled outpouching in the wall of the descending aorta, which was thought to be the source of bleeding. At thoracotomy, there were firm adhesions between the descending aorta and the left S6. The aorta was clamped and the adhesions were removed revealing a defect in the aortic wall with thrombus. The defect was sutured. A penetrating atherosclerotic ulcer and intramural hematoma were diagnosed based on the radiological and operative findings.

Chemical contamination in aquatic ecosystems.

The 21st Century's Center of Excellence (COE) Program "Coastal Marine Environmental Research" in Ehime University, funded by the Ministry of Education, Culture, Sports, Science and Technology, Government of Japan, started its activities in October 2002. One of the core projects of the COE Program in Ehime University is "studies on environmental behavior of hazardous chemicals and their toxic effects on wildlife". This core project deals with studies of the local and global distribution of environmental contaminants in aquatic ecosystems, retrospective analysis of such chemicals, their toxicokinetics in humans and wildlife, molecular mechanisms to determine species-specific reactions, and sensitivity of chemically induced effects, and with the development of methodology for risk assessment for the conservation of ecological and species diversity. This presentation describes our recent achievements of this project, including research on contamination by arsenic and organohalogen pollutants in the Mekong River basin and molecular mechanisms of morphologic deformities in dioxin-exposed red seabream (Pagrus major) embryos. We established the Environmental Specimen Bank (es-BANK) in Ehime University in 2004, archiving approximately 100000 cryogenic samples containing tissues of wildlife and humans that have been collected for the past 40 years. The CMES homepage offers details of samples through online database retrieval. The es-BANK facility was in operation by the end of 2005.

Toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in developing red seabream (Pagrus major) embryo: an association of morphological deformities with AHR1, AHR2 and CYP1A expressions.

The toxicity of dioxins such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is mainly mediated by the aryl hydrocarbon receptor (AHR), which regulates the multiple target genes including cytochrome P4501A (CYP1A). In general, bony fishes, which possess at least two distinct AHRs are one of the most sensitive vertebrates to TCDD in early life stage. However, the physiological and toxicological roles of piscine multiple AHRs are not fully understood, especially in marine fish. To understand which AHR is responsible for TCDD toxicity in a marine fish species, we characterized the early life stage toxicity related to the expression of AHRs and CYP1A in red seabream (Pagrus major). The embryos at 10h post-fertilization (hpf) were treated with 0-100 microg/L TCDD for 80 min waterborne exposure. TCDD dose-dependently elicited developmental toxicities including mortality, yolk sac edema, retarded body growth, spinal deformity, reduced heart rate, shortened snout, underdeveloped fin, heart, and lower jaw. Intriguingly, hemorrhage and pericardium edema, typical TCDD developmental defects noticed in other fish species, were not found in red seabream until test termination. The EC(egg)50s for yolk sac edema, underdeveloped fin, and spinal deformity were 170, 240, and 340 pg/g, respectively. The LC(egg)50 was 360 pg/g embryo, indicating that this species is one of the most sensitive fishes to TCDD toxicity. The expression levels of rsAHR1, rsAHR2 and CYP1A mRNAs were also determined in different developmental stages. The rsAHR2 mRNA expression dose-dependently increased following TCDD exposure, while rsAHR1 mRNA level was not altered. Level of rsAHR2 mRNA measured by two-step real-time PCR was 30 times higher than rsAHR1 in embryos treated with the highest dose. Temporal patterns of rsAHR2 and CYP1A mRNAs were similar in TCDD-treated embryos, representing a significant positive correlation between rsAHR2 and CYP1A mRNA levels, but not between rsAHR1 and CYP1A. In comparison of temporal trends of TCDD-induced AHRs and CYP1A expression, and developmental toxicities, the highest expression of rsAHR2 and CYP1A mRNA were detected prior to the appearance of maximal incidence of TCDD toxic manifestations. These results suggest that rsAHR2 may be dominantly involved in the transcriptional regulation of CYP1A, and several TCDD defects are dependent on the alteration of rsAHR2 and/or rsAHR2-CYP1A signaling pathway that is controlled through their expression levels.

Molecular characterization of the aryl hydrocarbon receptors (AHR1 and AHR2) from red seabream (Pagrus major).

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of planar halogenated aromatic hydrocarbons (PHAHs). Bony fishes exposed to PHAHs exhibit a wide range of developmental defects. However, functional roles of fish AHR are not yet fully understood, compared with those of mammalian AHRs. To investigate the potential sensitivity to PHAHs toxic effects, an AHR cDNA was initially cloned and sequenced from red seabream (Pagrus major), an important fishery resource in Japan. The present study succeeded in identifying two highly divergent red seabream AHR cDNA clones, which shared only 32% identity in full-length amino acid sequence. The phylogenetic analysis revealed that one belonged to AHR1 clade (rsAHR1) and another to AHR2 clade (rsAHR2). The rsAHR1 encoded a 846-residue protein with a predicted molecular mass of 93.2 kDa, and 990 amino acids and 108.9 kDa encoded rsAHR2. In the N-terminal half, both rsAHR genes included bHLH and PAS domains, which participate in ligand binding, AHR/ARNT dimerization and DNA binding. The C-terminal half, which is responsible for transactivation, was poorly conserved between rsAHRs. Quantitative analyses of both rsAHRs mRNAs revealed that their tissue expression profiles were isoform-specific; rsAHR1 mRNA expressed primarily in brain, heart, ovary and spleen, while rsAHR2 mRNA was observed in all tissues examined, indicating distinct roles of each rsAHR. Furthermore, there appeared to be species-differences in the tissue expression profiles of AHR isoforms between red seabream and other fish. These results suggest that there are isoform- and species-specific functions in piscine AHRs.

[Infective endocarditis with splenic abscess and cerebral hemorrhage].

A 65-year-old man was admitted with ataxic gait and high fever. Brain magnetic resonance imaging (MRI) showed multiple cerebral hemorrhages and echocardiogram showed vegetations attached to the mitral valve and moderate mitral regurgitation. No microorganisms were identified by blood culture examination. Despite adequate treatment with antibiotics, large multiple splenic abscesses were detected by computed tomography (CT), the patient complained of fever and the value of CRP was increased again. We decided to first perform splenectomy, followed by mitral valve repair and maze operation. The pathology of the spleen showed findings consistent with large abscesses due to septic emboli. The postoperative course was uneventful.

[Emergent coronary artery bypass grafting using percutaneous cardiopulmonary support in a patient with a quadricuspid aortic valve; report of a case].

A 63-year-old man was admitted to our hospital for acute myocardial infarction. A cardiac catheter study showed 3 vessels coronary disease. He was treated by percutaneous coronary intervention for a left anterior descending arterial (LAD) lesion. Unfortunately, cardiac tamponade following stenting for LAD was complicated. A percutaneous cardiopulmonary support system was commenced along with an emergent coronary artery bypass grafting to the LAD and obtuse marginal branch. A quadricuspid aortic valve was discovered by an aortotomy and identified as Hurwitz-Roberts classification type b. Blood from the left coronary main trunk had already stopped. Intraaortic balloon pumping was instituted while weaning from the cardiopulmonary bypass. The patient's postoperative course was uneventful and all bypass grafts were sufficient. He was well 1 year after the operation.

Global distribution of radionuclides (137Cs and 40K) in marine mammals.

Concentrations of anthropogenic radionuclides were measured in the muscle of marine mammals collected from various locations all over the world, and the global distribution of 137Cs in marine mammals was investigated. 40K was detected in all the specimens of marine mammals with no apparent difference between regions. An anthropogenic radionuclide, 137Cs, was detected in most of the species of marine mammals. With regard to the worldwide distribution of 137Cs, the highest concentration was noticed in the U.K. coast, followed by Lake Baikal, and decreases toward the southern sampling points. A strong positive correlation was observed between 137Cs levels in the muscle of marine mammals and the ambient seawater. Marine mammals feeding on fishes showed a higher concentration factor (CF) for 137Cs than those feeding on cephalopods. To our knowledge, this is the first report on the global distribution of 137Cs and the effect of feeding habits on the CF values of 137Cs in marine mammals.