Tomohiro Imazuru

The minimum coronary artery diameter in which coronary spasm can be identified by synchrotron radiation coronary angiography

BACKGROUND Coronary vasospasm is defined as a temporary, intense narrowing of the coronary conduit artery. It brings about ischemic chest pain and becomes one of the causes of myocardial infarction. Coronary spasms are divided into two categories. One is the coronary spasm of the conduit artery and the other is the coronary microvascular spasm. Although coronary spasms are diagnosed with the images of coronary angiography, microvascular spasms cannot be diagnosed because of the limitations of conventional angiographic systems. However, synchrotron radiation coronary angiography (SRCA) can identify coronary arteries down to 100 microm in diameter in the beating heart and 50 microm in arrested heart. AIM The purpose of this study was to confirm whether microvascular spasms could be identified or not using SRCA, and then down that size identification was possible. METHODS The Langendorff perfusion system with isolated rat hearts was employed. Krebs-Henseleit solution (KH solution) was used as a perfusate. 10mM of 4-aminopyridine (4-AP: a voltage-gated potassium channel blocker; spasm inducer) was added to the KH solution and maintained for 5 min. SRCA was performed at pre-, during and 10 min after cessation of the KH solution with 4-AP. Coronary spasms were defined as a temporal 75% reduction of coronary arterial diameter. RESULTS AND CONCLUSION Multiple sizes of coronary arteries showed coronary spasms. The minimum stenosed coronary artery size was 100 microm. Since coronary microvascular spasms are seen in the arterioles (50-400 microm), coronary microvascular spasms may be diagnosed with the use of synchrotron radiation coronary angiography.

Thrombolytic therapy for delayed, in-hospital stroke after cardiac surgery

Five patients who had delayed stroke after cardiac surgery underwent intraarterial administration of a fibrinolytic agent for thromboembolism (n = 4) or thrombosis (n = 1) of the cerebral artery. Complete recanalization of the occluded artery was obtained in 3 patients and partial recanalization in 2. Additional angioplasty for basilar artery stenosis was performed in 1 patient. No patients exhibited rebleeding into the pericardial space or wound bleeding. All patients survived with moderate or full functional recovery. Immediate cerebral angiography and local thrombolysis may improve functional outcome and survival in patients with postcardiotomy cerebral thromboembolism.

Axillary artery and transapical aortic cannulation as an alternative to femoral artery cannulation

We present an experience with axillary artery and transapical aortic cannulation for cardiopulmonary bypass according to our indication. We could simply achieve antegrade flow using the two methods with satisfactory result.

An agonistic anti-BTLA mAb (3C10) induced generation of IL-10-dependent regulatory CD4+ T cells and prolongation of murine cardiac allograft.

Background The co-inhibitory receptor B and T lymphocyte attenuator (BTLA) has been implicated in the regulation of autoimmunity and may potentially play an important role in allograft tolerance. This study investigated the effect of an agonistic anti-BTLA mAb (3C10) in the fully major histocompatibility complex–mismatched murine cardiac transplantation. Methods CBA mice underwent transplantation of C57BL/6 hearts and received one dose of 3C10 on the day of transplantation (day 0) or four doses of 3C10 on day 0, 3, 6, and 9. Adoptive transfer studies were performed to determine whether regulatory cells were generated. Moreover, to confirm the requirement for regulatory T cell and Th-2 cytokines, anti-interleukin (IL)-2 receptor alpha antibody (PC-61) or anti-IL-10 antibody (JES-2A5) was administered to a 3C10-treated CBA recipient. Results CBA mice treated with one and four doses of 3C10 prolonged allograft survival (median survival times [MSTs], 43 and >100 days, respectively). Secondary CBA recipients given whole splenocytes or CD4+ cells from primary 3C10-treated CBA recipients had significantly prolonged survival of C57BL/6 hearts (MSTs, >100 in both). Also, flow cytometry studies showed an increased CD4+CD25+Foxp3+ cell population in 3C10-treated mice. Additionally, IL-2 and interferon-&ggr; production were suppressed in 3C10-treated mice, and IL-4 and IL-10 from 3C10-treated CBA mice increased. Moreover, 3C10 directly suppressed alloproliferation in a mixed leukocyte culture. However, administration of PC-61 or JES-2A5 clearly attenuated prolonged survival of 3C10-treated mice (MSTs, 15.5 and 13.5 days, respectively). Conclusion 3C10 could control acute rejection by its suppressive effect on alloreactive T cells and induction of IL-10-dependent regulatory CD4+ T cells.

Combined Aortic Resection and Stent Graft Insertion for Local Recurrence of Metastatic Lung Carcinoma Following Stereotactic Radiotherapy: A Case Report

Stereotactic radiotherapy (SRT) is a useful treatment for malignant ling tumors. However, SRT is associated with complications such as high local recurrence rate and radiation-induced lung injury. Herein, we report a case of combined aortic resection for after SRT. An 82-year-old man underwent SRT for the metastatic lung carcinoma of rectal cancer at left lower lobe. Three years later, chest computed tomography showed local recurrence at the site of radiotherapy, with suspected invasion of the descending aorta. Thoracotomy was performed after metastatic lung carcinoma interpolation of a stent graft in the descending aorta. Because the tumor firmly adhered to the aorta, left lower lung lobe and aortic wall resection was performed. Pathological findings revealed fibrous hypertrophy and adhesion between the visceral pleura and aorta. As shown in our case, combined aortic resection and stent graft insertion is an effective minimally invasive and safe treatment for SRT-induced tissue damage.

Yogurt Feeding Induced the Prolongation of Fully Major Histocompatibility Complex–Mismatched Murine Cardiac Graft Survival by Induction of CD4+Foxp3+ Cells

Yogurt is a nutrient-rich food and the beneficial effects of yogurt on both health and immunomodulatory effects are well documented. In this pilot study, we investigated the effects of commercially produced yogurt R-1 on alloimmune responses in a murine cardiac transplantation model. The R-1 is produced by Meiji Co., Ltd., and contains live and active lactic acid bacteria (lactobacillus bulgaricus OLL1073R-1) mainly. CBA (H2k) mice underwent transplantation of a C57BL/6 (H2b; B6) heart and received oral administration of 1 mL, 0.1 mL, and 0.01 mL of R-1 from the day of transplantation until 7 days afterward. Additionally, we prepared one group of CBA recipients given 1 mL of R-1 sterilized by microwave for 7 days. Histological and immunohistochemical studies were performed. Naïve CBA mice rejected B6 cardiac graft acutely (median survival time [MST]: 7 days). CBA recipients given of 1 mL of R-1 had significantly prolonged B6 allograft survival (MST, 27 days). However, other doses of 0.1 mL and 0.01 mL of R-1 did not prolonged allograft survival (MSTs, 9 days and 8.5 days, respectively). Also, CBA recipients administered microwaved R-1 had no prolongation of B6 allograft (MST, 9 days). Histological and immunohistochemical studies showed the cardiac allograft from R-1-exposed CBA recipients had preserved graft and vessel structure and the number of infiltrated CD4+, CD8+, and Foxp3+ cells in R-1-exposed CBA recipients increased, respectively. In conclusion, our findings imply that yogurt containing active lactic acid bacteria could change alloimmune responses partially and induce the prolongation of cardiac allograft survival via CD4+Foxp3+ regulatory cells.

Combination of Paeoniae Radix and Cnidii Rhizoma Prolonged Survival of Fully Mismatched Cardiac Allografts and Generated Regulatory Cells in Mice

In previous studies, we have demonstrated that Tokishakuyakusan (TJ-23) can prolong the survival of allogeneic cardiac grafts and induce regulatory T cells. In this study we investigated the effects of Paeoniae radix and Cnidii rhizoma, two components of TJ-23, on alloimmune responses in a murine cardiac transplantation model and whether the two agents have synergistic effect. CBA mice underwent transplantation of a C57BL/6 heart and received oral administration of 2 g/kg/day of Paeoniae radix, Cnidii rhizoma, or the mixture of two agents from the day of transplantation until 7 days afterward. Naïve CBA mice rejected C57BL/6 cardiac graft acutely (median survival time (MST): 7 days). Paeoniae radix and Cnidii rhizoma prolonged C57BL/6 allograft survival (MSTs: 13.5 and 15.5 days, resp.). However, the mixture of two agents prolonged C57BL/6 allograft survival indefinitely (MST > 100 days). Secondary CBA recipients given whole splenocytes from primary combination-treated CBA recipients with B6 cardiac allografts 30 days after grafting had prolonged survival of B6 hearts (MST: 33 days). Flow cytometry studies showed that the CD4+CD25+Foxp3+ regulatory cell population was increased in combination-treated recipients. Combination of Paeoniae radix and Cnidii rhizoma induced hyporesponsiveness to fully allogeneic cardiac allografts and may generate CD4+CD25+Foxp3+ regulatory cells in our model.

Administration of Thrombomodulin (CD141) could improve cardiac allograft survival in mice

Thrombomodulin (TM) is a promising natural anti-coagulant therapeutic protein that is effective in the treatment of disseminated intravascular coagulation. However, the mechanisms by which TM on micro-vessels enable the regulation of intimal hyperplasia remain elusive. We investigated the graft-protective effects of TM in a fully major histocompatibility complex-mismatched murine cardiac allograft transplantation model. CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of 0.2, 2.0, and 20.0 μg/day of TM for 8 days. Histological staining was conducted to assess the degree of inflammation and infiltration in the transplanted cardiac grafts. Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST] was 7 days). CBA recipients exposed to the above dosages had significantly prolonged allograft survival (MSTs were 16, 21, and 37.5 days, respectively). Histologic assessments from TM-exposed recipients 2 weeks after grafting showed that the myocardium and vessel structure in their allografts were clearly preserved, and that the infiltration of inflammatory cells around coronary arteries was suppressed. TM can induce the prolongation of fully major histocompatibility complex-mismatched cardiac allograft by exerting graft protective effects within the myocardium and coronary arteries.

Balloon Valvuloplasty for Evolut R Infolding: Useful Transesophageal Echocardiographic Monitoring for Diagnosis and Efficacy

An 89-year-old man with symptomatic severe aortic stenosis underwent 29-mm Evolut R (Medtronic, Minneapolis, Minnesota) implantation under general anesthesia. During the procedure, the Evolut R was deployed using the left subclavian artery approach. However, systemic hypotension persisted.

Surgical treatment of a huge hepatic artery aneurysm without revascularization—Case Report

Highlights • A huge hepatic artery aneurysm is a rare condition in aged patient.• Revascularization was not performed because of hepatic collateral circulation.• Postoperative liver function was preserved without revascularization.• Postoperative cholecystitis was observed despite hepatic collateral circulation.• Intraoperative ultrasound for hepatic collateral circulation may not be important.