[Non-A Non-B Aortic Dissection Complicated with Right Aortic Arch Treated by Extended Thoracic Aortic Repair]

A 44-year old man with a history of Stanford type B acute aortic dissection was admitted for the treatment of acute aortic dissection. Computed tomography( CT) scan showed a descending entry-type non-A non-B aortic dissection with a maximum diameter of 65 mm occurring in a patient with Edwards typeⅢ right aortic arch whose left subclavian artery was obliterated. The patient was initially treated conservatively and underwent one-stage extended aortic repair from the ascending aorta to the descending thoracic aorta via median sternotomy 22 days after the symptom onset. Although the patient suffered from right empyema postoperatively, he was discharged from the hospital on postoperative day 64 after 4 weeks antibiotics therapy. The patient was also complicated by right recurrent nerve palsy, hoarseness improved over the 8 months after surgery.

Effect of mechanical tension on fibroblast transcriptome profile and regulatory mechanisms of myocardial collagen turnover

Excess deposition of extracellular matrix in the myocardium is a predictor of reduced left ventricular function. Although reducing the hemodynamic load is known to improve myocardial fibrosis, the mechanisms underlying the reversal of the fibrosis have not been elucidated. We focused on the elasticity of myocardial tissue, which is assumed to influence the fibroblast phenotype. Normal and fibrotic myocardium were cultured in 16 kPa and 64 kPa silicone gel-coated dishes supplemented with recombinant TGFβ protein, respectively. Matrix-degrading myocardium was cultured in 64 kPa silicone gel-coated dishes with recombinant TGFβ protein and then in 16 kPa silicone gel-coated dishes. Cardiac fibroblasts were cultured in this three-part in vitro pathological models and compared. Fibroblasts differentiated into activated or matrix-degrading types in response to the pericellular environment. Comprehensive gene expression analysis of fibroblasts in each in vitro condition showed Selenbp1 to be one of the genes responsible for regulating differentiation of fibroblasts. In vitro knockdown of Selenbp1 enhanced fibroblast activation and inhibited conversion to the matrix-degrading form. In vivo knockdown of Selenbp1 resulted in structural changes in the left ventricle associated with progressive tissue fibrosis and left ventricular diastolic failure. Selenbp1 is involved in regulating fibroblast differentiation and appears to be one of the major molecules regulating collagen turnover in cardiac fibrosis.

[Surgical Outcomes of Prosthetic Valve Endocarditis]

Prosthetic valve endocarditis is a fatal complication after valve replacement surgery. Early surgical intervention is recommended for patients who suffer from complications such as heart failure, valve dysfunction, and abscesses. In the present study, we evaluated the clinical characteristics of 18 patients who underwent surgery for prosthetic valve endocarditis at our institution between December 1990 and August 2022, and examined the appropriateness of the timing and method of surgery, and whether there was improvement in cardiac function. Guidelines-based surgical intervention resulted in improved survival and improved cardiac function in the early and late postoperative period.

The effect of copper on the multiple carbon nanofilaments growths by the methane decomposition over the oxidized diamond-supported nickel–copper bimetallic catalyst

To clarify the indispensable parameters for the multiple carbon nanofilaments (CNFs) growths, in other words, having a unique Octopus-like morphology consisting of the Marimo-like carbon (MC), we have systematically studied to synthesize the MC by the decomposition of methane using oxidized diamond-supported Ni–Cu bimetallic catalysts. We discovered that a Cu addition of 20 wt.% by weight and a growth temperature in the region of 550 °C to 600 °C resulted in many CNF forms from a single catalyst particle, specifically the "Octopus-like" morphology of CNFs. We also discovered that the several CNFs forms might occur from the carbon dissolved in the sintered catalyst particles. We described a model process of the unique structure formation. We expect that the Octopus-like CNFs growth gives enough space volume in the MC for a mass transfer, consequently, it should contribute to realizing a higher power generation performance of a polymer electrolyte fuel cell (PEFC) although under a higher-voltage generation region.

Nrg1/ErbB signaling-mediated regulation of fibrosis after myocardial infarction

Appropriate fibrotic tissue formation after myocardial infarction (MI) is crucial to the maintenance of the heart's structure. M2-like macrophages play a vital role in post-MI fibrosis by activating cardiac fibroblasts. Because the mechanism by which post-MI cardiac fibrosis is regulated is not fully understood, we investigated, in vitro and in vivo, the cellular and molecular mechanisms of post-MI fibrotic tissue formation, especially those related to the regulation of cellular senescence and apoptosis. CD206⁺ F4/80⁺ CD11b⁺ M2-like macrophages collected from mouse hearts on post-MI day 7 showed increased expression of neuregulin 1 (Nrg1). Nrg1 receptor epidermal growth factor receptors ErbB2 and ErbB4 were expressed on cardiac fibroblasts in the infarct area. M2-like macrophage-derived Nrg1 suppressed both hydrogen peroxide-induced senescence and apoptosis of fibroblasts, whereas blockade of ErbB function significantly accelerated both processes. M2-like macrophage-derived Nrg1/ErbB/PI3K/Akt signaling, shown to be related to anti-senescence, was activated in damaged cardiac fibroblasts. Interestingly, systemic blockade of ErbB function in MI model mice enhanced senescence and apoptosis of cardiac fibroblasts and exacerbated inflammation. Further, increased accumulation of M2-like macrophages resulted in excessive post-MI progression of fibrosis in mice hearts. The molecular mechanism underlying the regulation of fibrotic tissue formation in the infarcted myocardium was shown in part to be attenuation of apoptosis and senescence of cardiac fibroblasts by the activation of Nrg1/ErbB/PI3K/Akt signaling. M2-like macrophage-mediated regulation of Nrg1/ErbB signaling has a substantial effect on fibrotic tissue formation in the infarcted adult mouse heart and is critical for suppressing the progression of senescence and apoptosis of cardiac fibroblasts.

[Surgical Resection Papillary Fibroelastoma Arising from Left Atrium:Report of a Case]

A 75-year-old man was admitted for cerebral infarction. Magnetic resonance imaging revealed parietal lobe cerebral infarction. Transesophageal echo and contrast-enhanced computed tomography indicated mobile and speckled mass arising from left atrium. He was diagnosed with cardiogenic cerebral embolism. Under cardiopulmonary bypass, resection of the mass including endocardium tissue was per formed. The resected specimen showed multiple small fronds resembling a sea anemone. Microscopic examination showed multiple branching fronds of paucicellular and avascular fibroelastic tissue lined by a single layer of endocardium. Pathological diagnosis was papillary fibroelastoma. Three years passed without recurrence.

Characteristics and outcome of suspected cerebrovascular disease in dogs: 66 cases (2009-2016)

OBJECTIVES

To characterise the clinical signs of suspected cerebrovascular disease in dogs.

MATERIALS AND METHODS

Medical records of one hospital were searched from November 2009 to December 2016 for dogs that suffered of cerebrovascular disease. We diagnosed cerebrovascular disease based on acute onset, clinical signs and magnetic resonance imaging findings. The medical history, clinical signs, concurrent disease, area of infarction, cerebrospinal fluid results, month at onset and outcome were investigated in the cerebrovascular disease group and in a control group (dogs with brain disorders other than cerebrovascular disease).

RESULTS

A total of 122 CVD cases were extracted from the 5312 patients that visited during the study period. Of these 122 cases, 66 (1.2%) matched the subject selection criteria of our study and were included in the analysis. Forebrain infarction was observed in 51 of 66 cases, of which 24 (47.1%) suffered from seizures. The number of dogs diagnosed with cerebrovascular disease was disproportionately high in August (nine of 59 cases) and December (13 of 59 cases). In the outcome survey, deterioration was observed in 11 of 55 cases.

CLINICAL SIGNIFICANCE

Seizure is an important clinical sign of cerebrovascular disease in dogs. There was a significant seasonal variation in the number of dogs diagnosed with cerebrovascular disease in Japan. Clinical features observed in this report differ from those of previous reports and highlight the need for additional research in this area.

[Subacute Pseudoaneurysm Formation after Sutureless Repair for Postinfarction Left Ventricular Rupture:Report of a Case]

A 71-year-old woman was admitted for cardiac tamponade due to left ventricular free wall rupture after acute myocardial infarction. Sutureless repair was performed for bleeding from the inferior wall. Fifteen days later, computed tomography demonstrated enlargement of a left ventricular pseudoaneurysm. Patch closure using a vascular prosthesis was performed through left thoracotomy. No recurrence of the left ventricular aneurysm has been observed since.

Early cardiac contractility outcome of reoperative coronary artery bypass grafting using right gastroepiploic artery

BACKGROUND AND AIM OF THE STUDY

Reoperative coronary artery bypass grafting (redo CABG) still carries higher mortality and increased morbidity compared with primary CABG. In this study, we retrospectively reviewed our operative outcome of redo CABG to evaluate the impact of the left anterolateral thoracotomy approach using the right gastroepiploic artery (RGEA).

METHODS

Between 1994 and 2020, 11 patients (mean age 60.3 ± 13.1 years; nine men, two women) underwent isolated redo CABG using the RGEA via the left anterolateral thoracotomy.

RESULTS

The mean duration from the initial CABG was 128.3 ± 88.4 months. Redo CABG was performed because of graft occlusion in six patients (54.5%), graft stenosis in one patient (9.1%), and progressive disease of previously ungrafted vessels in four patients (36.4%). The total number of bypasses using RGEA (including Y-composite vein grafts) was 16 (four left anterior descending branches, two diagonal branches, five circumflex branches, five right coronary arteries). No residual graft injury, major comorbidity, or in-hospital death was observed. Changes in echocardiographic values before and after redo CABG were 210.9 ± 48.2 ml and 175.0 ± 41.4 ml in left ventricular end-diastolic volume, 130.2 ± 49.2 ml and 94.4 ± 33.0 ml in left ventricular end-systolic volume, and 45.6 ± 11.0% and 52.2 ± 10.7% in left ventricular ejection fraction, respectively. These parameters significantly improved after redo CABG.

CONCLUSIONS

Redo CABG with RGEA grafting via the left anterolateral thoracotomy approach is a safe and effective surgical procedure especially in improving cardiac contractility in patients who required revascularization.

[Rapid Growing Thoracic Aortic Aneurysm in a Patient with Relapsing Polychondritis]

A 26-year-old man with relapsing polychondritis was admitted for the treatment of multiple thoracic aortic aneurysms in the ascending and descending aorta. Descending thoracic aortic aneurysm showed rapid expansion, therefore, the patient underwent an extended thoracic aortic repair from the ascending aorta to the descending aorta via anterolateral thoracotomy and partial sternotomy. Although postoperative course was uneventful, aortic root enlargement and severe aortic insufficiency progressed over the next two years. He and his family refused redo surgical intervention and the patient died of heart failure. Careful perioperative follow-up may be mandatory in a patient with relapsing polychondritis complicated by cardiovascular disease.

Cell barrier function of resident peritoneal macrophages in post-operative adhesions

Post-operative adhesions are a leading cause of abdominal surgery-associated morbidity. Exposed fibrin clots on the damaged peritoneum, in which the mesothelial barrier is disrupted, readily adhere to surrounding tissues, resulting in adhesion formation. Here we show that resident F4/80^HighCD206⁻ peritoneal macrophages promptly accumulate on the lesion and form a ‘macrophage barrier’ to shield fibrin clots in place of the lost mesothelium in mice. Depletion of this macrophage subset or blockage of CD11b impairs the macrophage barrier and exacerbates adhesions. The macrophage barrier is usually insufficient to fully preclude the adhesion formation; however, it could be augmented by IL-4-based treatment or adoptive transfer of this macrophage subset, resulting in robust prevention of adhesions. By contrast, monocyte-derived recruited peritoneal macrophages are not involved in the macrophage barrier. These results highlight a previously unidentified cell barrier function of a specific macrophage subset, also proposing an innovative approach to prevent post-operative adhesions.

Peritoneal adhesions are a major cause of complications after abdominal surgery. Here the authors use a post-operative abdominal adhesion model in mice to show that resident F4/80^HighCD206⁻ macrophages form a protective barrier that can be enhanced by IL-4 administration or adoptive transfer of these cells.

Effects of Obesity on Outcomes of Acute Type A Aortic Dissection Repair in Japan

Background: The prevalence of obesity among Japanese acute type A aortic dissection (ATAAD) patients and its effect on repair outcomes remain to be elucidated.

Methods and Results: The prevalence of obesity (body mass index [BMI] ≥30.0 kg/m²) among 1,059 patients (mean [±SD] age 64.3±12.7 years) who underwent ATAAD repair between 1990 and 2018 was compared with that among the general Japanese population (National Health and Nutrition Survey data). The prevalence of obesity among male patients (17.1% [6/35], 20.0% [18/90], and 14.4% [20/139] for those aged 20–39, 40–49, and 50–59 years, respectively) was significantly higher than that among the age- and sex-matched general population. The 1,059 patients were divided into groups according to weight (normal [BMI <25.0 kg/m²; n=742], overweight [BMI 25.0–29.9 kg/m²; n=248], or obese [BMI ≥30.0 kg/m²; n=69]). Comparing the normal weight, overweight, and obese groups revealed significant differences among the 3 groups in median cardiopulmonary bypass time (143, 167, and 183 min, respectively), ventilation >48 h (44.5%, 60.1%, and 78.3%, respectively), and in-hospital mortality (7.0%, 7.3%, and 17.4%, respectively), but not in 30-day survival. Shock, visceral malperfusion, operation time >360 min, obesity, and coronary malperfusion were identified as predictors of in-hospital mortality.

Conclusions: The prevalence of obesity is increased among Japanese male patients with ATAAD aged ≤59 years. Obesity may increase these patients’ operative risk; overweight does not.

Early superior mesenteric artery revascularization for acute type A aortic dissection with cardiac tamponade and mesenteric malperfusion

We report herein the successful treatment of a case of acute type A aortic dissection complicated by cardiac tamponade and mesenteric malperfusion. The patient was a 60-year-old man with back and abdominal pain and in shock, who was transported to our hospital 2 h after symptom onset. Computed tomography revealed DeBakey type I dissection with massive hemopericardium and obstruction of both the celiac artery and superior mesenteric artery. After emergency pericardiotomy and removal of the hematoma, superior mesenteric artery-external iliac artery bypass was constructed with a vein graft, and this restored mesenteric perfusion. Open distal hemiarch replacement was then performed. The postoperative course was uneventful. Superior mesenteric artery revascularization achieved immediately after release of the cardiac tamponade prevented further mesenteric ischemia and paved the way for the aortic repair.

[Bioprosthetic Mitral Valve Thrombosis in Patient with Antiphospholipid Antibody Syndrome;Report of a Case]

A 66-year-old woman with primary antiphospholipid antibody syndrome (APS) was admitted due to severe dyspnea. Eight months prior to admission, she underwent bioprosthetic mitral valve replacement for mitral valve stenosis and regurgitation. Transthoracic echocardiogram showed thickening bioprosthetic valve leaflets and severe valve stenosis. Emergency reoperation for artificial valve failure was performed. The explanted bioprosthetic valve showed massive thrombus formation. After the operation, she started strict anticoagulant and antiplatelet therapies and was discharged without recurrence of valve thrombosis.

[Successful Surgical Repair of the Aortic Annular Infective Endocarditis with Subvalvular Abscess;Report of a Case]

A 49-year-old female was admitted to our hospital with a history of fever for 2 weeks and consciousness disorder.Transthoracic echocardiography demonstrated aortic regurgitation with a mobile fibrous band adhering to the right cusp. Infective endocarditis was diagnosed by positive blood culture and echocardiographic findings. Emergent aortic valve surgery was performed because of uncontrollable infection. A destroyed aortic annulus and subvalvular abscess was found during the operation. Removal of abscess tissue and annuloplasty with self-pericardium were successfully performed.

[Hybrid Repair of Distal Arch Aortic Aneurysm:Total Aortic Arch Repair with the Lupiae Vascular Graft and Thoracic Endovascular Aortic Repair;Report of Two Cases]

Surgical treatment for distal arch aortic aneurysm is generally invasive, and there is no definitive approach for it. We report 2 cases of men who was admitted for the treatment of aortic aneurysm. First case is a 78-year-old man. Two saccular aneurysm were observed on distal aortic arch and descending aorta by contrast-enhanced computed tomography. Two staged-repair was performed with using the Lupiae vascular graft and thoracic endovascular aortic repair(TEVAR). The postoperative course was uneventful, and he was discharged on day 21 after 1st operation. Second case is a 68-yearold man. Dessecting aneurysm was observed on distal aortic arch and descending aorta 3 months after incidence of type B aortic dissection. Two staged-repair was performed with using the Lupiae vascular graft and TEVAR. However, additional TEVAR was performed for enlargement of descending aorta half a year after 1st operation. Two staged-repair using Lupiae vascular graft and TEVAR was useful for alleviating a burden of a patient and avoiding paraplegia.

IL-4 as a Repurposed Biological Drug for Myocardial Infarction through Augmentation of Reparative Cardiac Macrophages: Proof-of-Concept Data in Mice

Recent research has shown that reparative (alternatively activated or M2) macrophages play a role in repair of damaged tissues, including the infarcted hearts. Administration of IL-4 is known to augment M2 macrophages. This translational study thus aimed to investigate whether IL-4 administration is useful for the treatment of myocardial infarction. Long-acting IL-4 complex (IL-4c; recombinant IL-4 mixed with anti-IL-4 monoclonal antibody as a stabilizer) was administered after coronary artery ligation in mice. It was observed that IL-4c administration increased accumulation of CD206+F4/80+ M2-like macrophages predominantly in the injured myocardium, compared to the control. Sorted cardiac M2-like macrophages highly expressed wide-ranging tissue repair-related genes. Indeed, IL-4c administration enhanced cardiac function in association with reduced infarct size and enhanced tissue repair (strengthened connective tissue formation, improved microvascular formation and attenuated cardiomyocyte hypertrophy). Experiments using Trib1 -/- mice that had a depleted ability to develop M2 macrophages and other in-vitro studies supported that these IL-4-mediated effects were induced via M2-like macrophages. On the other hand, when administered at Day 28 post-MI, the effects of IL-4c were diminished, suggesting a time-frame for IL-4 treatment to be effective. These data represent proof-of-concept of efficacy of IL-4 treatment for acute myocardial infarction, encouraging its further development.

GFRA2 Identifies Cardiac Progenitors and Mediates Cardiomyocyte Differentiation in a RET-Independent Signaling Pathway

A surface marker that distinctly identifies cardiac progenitors (CPs) is essential for the robust isolation of these cells, circumventing the necessity of genetic modification. Here, we demonstrate that a Glycosylphosphatidylinositol-anchor containing neurotrophic factor receptor, Glial cell line-derived neurotrophic factor receptor alpha 2 (Gfra2), specifically marks CPs. GFRA2 expression facilitates the isolation of CPs by fluorescence activated cell sorting from differentiating mouse and human pluripotent stem cells. Gfra2 mutants reveal an important role for GFRA2 in cardiomyocyte differentiation and development both in vitro and in vivo. Mechanistically, the cardiac GFRA2 signaling pathway is distinct from the canonical pathway dependent on the RET tyrosine kinase and its established ligands. Collectively, our findings establish a platform for investigating the biology of CPs as a foundation for future development of CP transplantation for treating heart failure.

[Total Aortic Arch Replacement by Minimally Invasive Approach in a Patient with Permanent Tracheostomy;Report of a Case]

Standard full median sternotomy for total aortic arch replacement in patients with tracheostomy has higher risks for mediastinitis and graft infection. To avoid surgical site infection, it is necessary to keep a sufficient distance between the tracheostomy and the site of surgical skin incision. We herein report a case of a 74-year-old man with permanent tracheostomy after total laryngectomy, who underwent total aortic arch replacement for an aneurysm. Antero-lateral thoracotomy in the 2nd intercostal space with lower partial sternotomy( ALPS approach) provided an enough distance between the tracheostomy and the surgical field. It also provided a good view for surgical procedure and enabled the standard setup of cardiopulmonary bypass with ascending aortic cannulation, venous drainage from the right atrium and the left ventricular venting through the upper right pulmonary vein. The operation was completed in 345 minutes and the patient was discharged on the 11th postoperative day without any complications.

Alternatively activated macrophages determine repair of the infarcted adult murine heart

Alternatively activated (also known as M2) macrophages are involved in the repair of various types of organs. However, the contribution of M2 macrophages to cardiac repair after myocardial infarction (MI) remains to be fully characterized. Here, we identified CD206+F4/80+CD11b+ M2-like macrophages in the murine heart and demonstrated that this cell population predominantly increases in the infarct area and exhibits strengthened reparative abilities after MI. We evaluated mice lacking the kinase TRIB1 (Trib1-/-), which exhibit a selective depletion of M2 macrophages after MI. Compared with control animals, Trib1-/- mice had a catastrophic prognosis, with frequent cardiac rupture, as the result of markedly reduced collagen fibril formation in the infarct area due to impaired fibroblast activation. The decreased tissue repair observed in Trib1-/- mice was entirely rescued by an external supply of M2-like macrophages. Furthermore, IL-1α and osteopontin were suggested to be mediators of M2-like macrophage-induced fibroblast activation. In addition, IL-4 administration achieved a targeted increase in the number of M2-like macrophages and enhanced the post-MI prognosis of WT mice, corresponding with amplified fibroblast activation and formation of more supportive fibrous tissues in the infarcts. Together, these data demonstrate that M2-like macrophages critically determine the repair of infarcted adult murine heart by regulating fibroblast activation and suggest that IL-4 is a potential biological drug for treating MI.

Gate-Tunable Spin-Charge Conversion and the Role of Spin-Orbit Interaction in Graphene

The small spin-orbit interaction of carbon atoms in graphene promises a long spin diffusion length and the potential to create a spin field-effect transistor. However, for this reason, graphene was largely overlooked as a possible spin-charge conversion material. We report electric gate tuning of the spin-charge conversion voltage signal in single-layer graphene. Using spin pumping from an yttrium iron garnet ferrimagnetic insulator and ionic liquid top gate, we determined that the inverse spin Hall effect is the dominant spin-charge conversion mechanism in single-layer graphene. From the gate dependence of the electromotive force we showed the dominance of the intrinsic over Rashba spin-orbit interaction, a long-standing question in graphene research.

Allogeneic Mesenchymal Stromal Cells Transplanted Onto the Heart Surface Achieve Therapeutic Myocardial Repair Despite Immunologic Responses in Rats

Background

Transplantation of allogeneic mesenchymal stromal cells (MSCs) is a promising treatment for heart failure. We have shown that epicardial placement of cell sheets markedly increases donor cell survival and augments therapeutic effects compared with the current methods. Although immune rejection of intramyocardially injected allogeneic MSCs have been suggested, allogeneic MSCs transplanted on the heart surface (virtual space) may undergo different courses. This study aimed to elucidate immunologic response against epicardially placed allogeneic MSCs, rejection or acceptance of these cells, and their therapeutic effects for heart failure.

Methods and Results

At 4 weeks after coronary artery ligation, Lewis rats underwent epicardial placement of MSC sheets from syngeneic Lewis or allogeneic Fischer 344 rats or sham treatment. At days 3 and 10 after treatment, similar ratios (≈50% and 30%, respectively) of grafted MSCs survived on the heart surface in both MSC sheet groups. By day 28, survival of syngeneic MSCs was substantially reduced (8.9%); survival of allogeneic MSCs was more extensively reduced (0.2%), suggesting allorejection. Correspondingly, allogeneic MSCs were found to have evoked an immunologic response, albeit low level, as characterized by accumulation of CD4⁺ T cells and upregulation of interleukin 6. Despite this alloimmune response, the allogeneic MSC sheet achieved myocardial upregulation of reparative factors, enhanced repair of the failing myocardium, and improved cardiac function to the equivalent degree observed for the syngeneic MSC sheet.

Conclusions

Allogeneic MSCs placed on the heart surface evoked an immunologic response; however, this allowed sufficient early phase donor cell survival to induce equivalent therapeutic benefits to syngeneic MSCs. Further development of this approach toward clinical application is warranted.

Experimental Demonstration of Room-Temperature Spin Transport in n-Type Germanium Epilayers

We report an experimental demonstration of room-temperature spin transport in n-type Ge epilayers grown on a Si(001) substrate. By utilizing spin pumping under ferromagnetic resonance, which inherently endows a spin battery function for semiconductors connected with a ferromagnet, a pure spin current is generated in the n-Ge at room temperature. The pure spin current is detected by using the inverse spin-Hall effect of either a Pt or Pd electrode on n-Ge. From a theoretical model that includes a geometrical contribution, the spin diffusion length in n-Ge at room temperature is estimated to be 660 nm. Moreover, the spin relaxation time decreases with increasing temperature, in agreement with a recently proposed theory of donor-driven spin relaxation in multivalley semiconductors.

Characterization and evolutionary analysis of tributyltin-binding protein and pufferfish saxitoxin and tetrodotoxin-binding protein genes in toxic and nontoxic pufferfishes

Understanding the evolutionary mechanisms of toxin accumulation in pufferfishes has been long-standing problem in toxicology and evolutionary biology. Pufferfish saxitoxin and tetrodotoxin-binding protein (PSTBP) is involved in the transport and accumulation of tetrodotoxin and is one of the most intriguing proteins related to the toxicity of pufferfishes. PSTBPs are fusion proteins consisting of two tandem repeated tributyltin-binding protein type 2 (TBT-bp2) domains. In this study, we examined the evolutionary dynamics of TBT-bp2 and PSTBP genes to understand the evolution of toxin accumulation in pufferfishes. Database searches and/or PCR-based cDNA cloning in nine pufferfish species (6 toxic and 3 nontoxic) revealed that all species possessed one or more TBT-bp2 genes, but PSTBP genes were found only in 5 toxic species belonging to genus Takifugu. These toxic Takifugu species possessed two or three copies of PSTBP genes. Phylogenetic analysis of TBT-bp2 and PSTBP genes suggested that PSTBPs evolved in the common ancestor of Takifugu species by repeated duplications and fusions of TBT-bp2 genes. In addition, a detailed comparison of Takifugu TBT-bp2 and PSTBP gene sequences detected a signature of positive selection under the pressure of gene conversion. The complicated evolutionary dynamics of TBT-bp2 and PSTBP genes may reflect the diversity of toxicity in pufferfishes.

Dependence of average muscle fibre conduction velocity on voluntary contraction force

Average muscle fibre conduction velocity (CV) measured with multichannel surface electrodes decreases with time during sustained isometric contraction. Based on this property, CV is considered a candidate for an objective index to localized muscular fatigue. CV, however, also depends on many other factors that include muscle temperature and voluntary contraction force. In this paper, the effect of contraction force on CV was studied by defining not only the target force level but also the whole force trajectory. The contraction was isometric and lasted 14 s. The target force was set at four levels from 30% to 90% of the maximal voluntary contraction (MVC). Three typical muscles were studied in seven healthy male subjects. In the vastus lateralis, CV increased with contraction force in many cases. In the biceps brachii, CV decreased rapidly with time before the contraction force reached the target levels of 70% or 90% MVC. At these force levels, CV was smaller than that at 50% MVC. CV in the biceps consequently showed no apparent dependence on the contraction force. The tibialis anterior showed intermediate change in CV between the vastus lateralis and the biceps brachii. These results indicate that CV basically increases with contraction force, but this relationship becomes unclear when CV decreases rapidly with time.

Diurnal variation in neutrophil function

Neutrophil functions, including chemotaxis, reactive oxygen species (ROS)-producing capacity of neutrophils, and serum opsonic activity were investigated in 9 young healthy male volunteers. Venous blood of these volunteers was obtained under standardized conditions at 4-h intervals over a 24-h span. Neutrophil chemotaxis was evaluated by a modified Boyden technique, ROS-producing capacity of neutrophils and serum opsonic activity were measured by a simultaneous multiple measurement system based on luminol-dependent chemiluminescence and indicated by peak height and peak time. ROS-producing capacity of neutrophils and serum opsonic activity were activated in the daytime, and decreased from night to morning. There were negative correlations between the peak time of the luminol-dependent chemiluminescent response, neutrophil number (p<0.01) and segmented neutrophil number (p>0.01). On the other hand, no significant correlations were noted between serum opsonic activity and IgG, IgA, IgM, C3 or C4. In contrast, the peaks of neutrophil chemotaxis were at the wake-up time (6:00a.m.) and in the evening (6:00p.m.). This study indicates that diurnal variation of neutrophil function exists.

Successful surgical repair of the parachute mitral valve with mitral valve regurgitation

A 65-year-old woman with exercise-related dyspnea was admitted to our hospital. Transthoracic echocardiography demonstrated a large anomalous papillary muscle that originated from the posterior wall of the left ventricle and severe mitral valve regurgitation in systole. Cleft suture, 5-0 polytetrafluoroethylene sutures from a single papillary muscle to the anterior commissure leaflet (AC), 5-0 polypropylene sutures between AC and A1, and between A1 and A2, the double-orifice technique, and ring plasty with 32-mm semi-rigid ring was performed. Postoperative echocardiography showed an improvement in severe mitral valve regurgitation. At the 2-month follow-up, the patient was in good health. In the present case, the elderly patient with an isolated parachute mitral valve but without any other cardiac anomaly and presenting with mitral valve regurgitation is extremely rare. This case of mitral valvuloplasty for a parachute mitral valve with a single papillary muscle in an elderly woman has not been reported before.

Characterization of 5-hydroxytryptamine-induced contraction and acetylcholine-induced relaxation in isolated chicken basilar artery

The aim of the present study was to clarify the responsiveness of the chicken basilar artery to 5-hydroxytryptamine (5-HT) and acetylcholine (ACh) and to characterize the related receptor subtypes in vitro. Basilar arteries were obtained from freshly slaughtered broiler chickens. The 5-HT induced concentration-dependent contraction of the arteries. The concentration-response curves for 5-HT were shifted 30-fold to the right by methiothepin (a 5-HT(1) and 5-HT(2) receptor antagonist) and 3-fold to the right by ketanserin (a 5-HT(2) receptor antagonist). In the presence of ketanserin, the concentration-response curve for 5-HT was shifted 10-fold to the right by methiothepin. The pA(2) value for methiothepin was 8.26. The ACh induced concentration-dependent relaxation under conditions of precontraction by 5-HT. The concentration-response curve for ACh was shifted to the right by atropine [a nonselective muscarinic (M) receptor antagonist] and hexahydro-sila-difenidol hydrochloride, a p-fluoroanalog (pFHHSiD, an M(3) receptor antagonist), but not by pirenzepine (an M(1) receptor antagonist) or methoctramine (an M(2) receptor antagonist). The pA(2) value for pFHHSiD was 7.55. Nω-Nitro-l-arginine (a nitric oxide synthase inhibitor) inhibited ACh-induced relaxation by approximately 50%. These results suggest that 5-HT induces contraction via activation of 5-HT(1) and 5-HT(2) receptors and that ACh induces relaxation via activation of the M(3) receptor. The 5-HT(1) receptor might play a dominant role in 5-HT-induced contraction. One of the factors involved in ACh-induced relaxation is probably nitric oxide released from endothelial cells.

Successful surgical repair of pulmonary artery aneurysm and regurgitation

Pulmonary artery aneurysm (PAA) is generally a rare lesion, and there is no definitive approach for it. We report the case of a 45-year-old man who was admitted for the evaluation of dyspnea. In childhood, he had been diagnosed with PAA with congenital pulmonary valve stenosis and regurgitation, and he had a percutaneous transvenous pulmonary valve commissurotomy. Transthoracic echocardiogram showed dilatation of the right atrium and right ventricle, with right ventricular hypertrophy. There was severe pulmonary valve regurgitation, and the main pulmonary artery was dilated to 68 mm in diameter. From the surgical findings, the left leaflet of pulmonary valve was torn from commissure with failure to coapt with the other leaflet. After direct sutures of edges of the left leaflet, a nearly normal valvular competence was restored. The PAA was repaired with a Y-shaped 24 × 12 mm Dacron graft replacement. The postoperative course was uneventful, and the patient was discharged.

Late-stage non-anastomotic rupture of axillo-bifemoral bypass graft

An 82-year-old woman, who underwent axillo-bifemoral bypass for infrarenal aortic occlusion and peripheral arterial occlusive disease 9 years before, was admitted to our hospital for swelling in the left subclavicular region. Ultrasound examination revealed a leak in the wall of the bypass graft with the formation of a false aneurysm. No signs of infection, either locally or systemically, were observed. Resection of the aneurismal segment with interposition using a Dacron graft was performed. Macroscopic findings during surgery confirmed an intact anastomotic region of the left axillary artery and Dacron graft. Two possible mechanisms for the formation of this false aneurysm, either cumulative stress on the graft over the years or Dacron graft biodegradation, were hypothesized.

Cardiac varix in the right atrium

A 73-year old man underwent transthoracic and transoesophageal echocardiography and computed tomography, which revealed what appeared to be an asymptomatic primary mobile tumour located in the right atrium. During surgery, the mass was found to be associated with the right atrial septum and was subsequently resected. Histopathology of the mass revealed a cardiac varix with phleboliths. The patient had an uneventful postoperative course and no signs of recurrence at the 10-month follow-up.

Surgical treatment for thoracic aneurysms: comparison of stent grafting and open surgery

OBJECTIVES

Early and mid-term results of stent graft (SG) treatment for thoracic aortic aneurysms (thoracic endovascular aneurysm repair: TEVAR) were retrospectively compared with open surgical treatment.

METHODS

The records of 213 patients in whom single thoracic aortic aneurysm repairs had been performed in our department from January 2006 through August 31, 2009 were reviewed. Acute aortic dissection was excluded. Each case was reviewed for indications for TEVAR from an anatomical standpoint. Among 62 cases in which TEVAR was indicated, 30 (SG group) were treated by TEVAR and 32, by open surgery (OP group). Early and mid-term results were analyzed retrospectively in both groups.

RESULTS

There were no operative deaths in either group. The SG group demonstrated significantly less operative bleeding, a shorter operative time, and shorter postoperative hospital stay compared with the OP group. There were 3 deaths in the SG group and 4 in the OP group, which occurred within an average of 656.4 days during the follow up period. The 3 year actuarial survival rate was 88.7% in the SG group and 87.1% in the OP group, and there were no significant differences between the groups.

CONCLUSION

Although early and mid-term results of TEVAR and open surgery were similar, TEVAR is generally less invasive and may be preferable for high-risk patients, compared with open surgical repair. (English Translation of Jpn J Vasc Surg 2010; 19: 51-56.).

Hepatic artery pseudoaneurysm with extrahepatic biliary obstruction

Hepaticartery pseudoaneurysms are a rare complication of chronic pancreatitis. However, giant pseudoaneurysms (80 mm) and complicated biliary obstructions are extremely rare. This article reports a 75 year-old man with chronic pancreatitis that presented as upper abdominal pain and obstructive jaundice. Computed tomography revealed a hepatic artery pseudoaneurysm measuring 80 × 72 × 70 mm. We performed aneurysm resection and common hepatic artery bypass, using a great saphenous vein graft in the patient. The postoperative course was uneventful, and he was discharged on the 10th postoperative day. However, on the 135th postoperative day, he died of massive hemorrhage into the peritoneal cavity.

Apico-aortic conduit for aortic stenosis in a patient with chronic thoracic wall infection

We report a case of an apico-aortic bioprothesis-valved conduit for a 70-year-old-woman with symptomatic, severe aortic stenosis and severe calcification of the ascending aorta. She had a history of mastectomy and radiation therapy for breast cancer and was suffering from radiodermatitis and chronic thoracic wall infection. Transthoracic echocardiography showed severe aortic valve stenosis with heavy calcification and high aortic valve pressure gradients. In patients with a chronically infected thoracic wall, median sternotomy is considered to be a high risk procedure, resulting in postoperative mediastiniti; therefore, we applied a technique in which we used an apico-aortic conduit via posterolateral thoracotomy. We underwent apico-aortic bypass with a hand-made composite graft: 19-mm bioprosthetic valve and a 22-mm woven polyester vascular graft. The surgical intervention successfully decreased pressure gradient across the aortic valve, also separating an incision from chronic infection allowed us to avoid postoperative mediastinitis. The patient had remained in good condition for 15 months without developing any complications.

[Emergency stent placement after descending aortic replacement with chronic aortic dissection]

A 49-year-old man with asymptomatic chronic aneurysmal dissection was admitted to our hospital. He had undergone ascending aortic replacement for type A aortic dissection 7 months before. We performed descending aortic replacement for chronic aneurysmal dissection. Renal dysfunction appeared 1 day after the operation. Contrast-enhanced computed tomography indicated that the true lumen was severely compressed by a false lumen, and that the origins of the renal artery were occluded. We performed emergency endovascular stent placement to dilate the true lumen. Immediately after this procedure, renal ischemia improved. The postoperative course was uneventful. An endovascular approach using bare stent can be a treatment option that is less invasive and prompter for a patient with renal ischemia resulting from aortic dissection.