P5370Pulmonary pressure overload stimulates cardiac stem or progenitor cell-derived cardiac regeneration in the right ventricular area

Introduction and purpose

The number of patients with right heart failure due to pulmonary hypertension has been increasing. Although several drugs have reportedly improved pulmonary hypertension, no treatments have been established for decompensated right heart failure. The heart has an innate ability to regenerate, and cardiac stem or progenitor cells (e.g., side population [SP] cells) have been reported to contribute to the regeneration process. However, their contribution to right ventricular pressure overload has not been clarified. Here, this regeneration process was evaluated using a genetic fate-mapping model.

Methods and results

We used Cre-LacZ mice, in which more than 99.9% of the cardiomyocytes in the left ventricular field were positive for 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-gal) staining immediately after tamoxifen injection. Then, we performed either a pulmonary binding (PAB) or sham operation on the main pulmonary tract. In the PAB-treated mice, the right ventricular cavity was significantly enlarged (right-to-left ventricular [RV/LV] ratio, 0.24±0.04 in the sham group and 0.68±0.04 in the PAB group). Increased peak flow velocity in the PAB group (1021±80 vs 1351±62 mm/sec) was confirmed by echocardiography. One month after the PAB, the PAB-treated mice had more X-gal-negative (newly generated) cells than the sham mice (94.8±34.2 cells/mm2 vs 23.1±10.5 cells/mm2; p<0.01). The regeneration was biased in the RV free wall (RV free wall, 225.5±198.7 cells/mm2; septal area, 88.9±56.5/mm2; LV lateral area, 46.8±22.0/mm2; p<0.05). To examine the direct effects of PAB on the cardiac progenitor cells, bromodeoxyuridine was administered to the mice daily until 1 week after the PAB operation. Then, the hearts were isolated and SP cells were harvested. The SP cell population increased from 0.65±0.23% in the sham mice to 1.87% ± 1.18% in the PAB-treated mice. Immunostaining analysis revealed a significant increase in the number of BrdU-positive SP cells, from 11.6±2.0% to 44.0±18%, therefore showing SP cell proliferation.

Conclusions

Pulmonary pressure overload stimulated cardiac stem or progenitor cell-derived regeneration with a RV bias, and SP cell proliferation may partially contribute to this process.

Acknowledgement/Funding

JSPS KAKENHI Grant Number JP 17K17636, GSK Japan Research Grant 2016

P4-09-25: Impact of Body Mass Index (BMI) for Clinical Outcomes in Japanese Breast Cancer Patients

Background: Obesity is risk factor of breast cancer incidence in postmenopausal women including Japanese population. Currently, many clinical trials data were shown that obesity may be one of prognostic factors after primary treatment in postmenopausal breast cancer patients. However, the proportion of obesity is large different between Asain and Western populations in all breast cancer patients. There is a little paper about relationship between body mass index (BMI) and prognosis after surgery in Asian breast cancer population.

Methods: We conducted retrospective analysis about BMI and outcome after primary treatment in Japanese breast cancer patients. We reviewed the clinical data (height, weight, BMI, ER status, HER status, and outcome) based on our medical reports in our single institution. This research object is 1,100 patients with primary breast cancer who operated between Jan 2003 and Jan 2006 in our institution. Median follow up was 59 months (1-97). All patients are categorized into four groups according to BMI. The range of BMI is less than 18.5 kg/m2, from 18.5 to 24.9 kg/m2, 25 to 29.9 kg/m2, more than 30 kg/m2 in underweight, normal, overweight and obesity groups, respectively. Patient's characteristics are well balanced excluding age and menopausal status. Nobody is obesity in young women (less than 35 years old). The correlation BMI with disease free survival (DFS) and overall survival (OS) were statistically analyzed by using the Cox hazard model.

Results: 785 (71.3%), 88 (8%), 192 (17.5%), 35 (3.2%) patients were categorized into normal, underweight, overweight obesisty groups, respectively. Breast cancer recurrences including local and distant metastases were occurred in 126 patients (11.5%).66 (6%) patients died due to breast cancer recurrence (54 patients) and other disease (8 patients). The multivariate hazard ratio (HR) in obesity groups was tend to be high compared with normal groups in disease free survival and overall survival. HR for OS was 4.30 (95%CI, 1.79−10.3) in obesity group. However, there are no statistical significant differences among four groups. Especially, HR for DFS and OS was 2.90 (95% CI 1.15−7.30 p=0.024) and 7.05(95%CI 2.38−20.8 P&lt;0.001) in obesity group compared with normal group in ER positive patients, respectively. However, there are no statistical significant difference for DFS and OS among four groups in ER negative patients.

Conclusions: The proportion of obesity is very lower in Japanese population (3.2%) than Western population (about 25–30%). However, obesity might be risk factor for DFS and OS in Japanese breast cancer patients with ER positive similar with Western countries. The different proportion of BMI may be influenced the different overall survival rate in lymph node negative breast cancer patients between Japan and Western countries. This study is a first report of the association between obesity and clinical outcomes in Japanese breast cancer patients. However, a number of patients were limited and this study is retrospective analyses including heterogeneous subtypes in single institution. A large scale cohort study should be conducted based on the clinical trial in Japanese population.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-09-25.

Thin Observation Module by Bound Optics (TOMBO): Concept and Experimental Verification

A compact image-capturing system called TOMBO (an acronym for thin observation module by bound optics) is presented in which the compound-eye imaging system is utilized to achieve a thin optical configuration. The captured multiple images are processed to retrieve the image of the target object. For image retrieval, two kinds of processing method are considered: image sampling and backprojection. Computer simulations and preliminary experiments were executed on an evaluation system to verify the principles of the system and to clarify the issues related to its implementation.

[High-dose chemotherapy with autologous peripheral blood stem cell transfusion in the treatment of advanced testis cancer]

Four patients with advanced testis cancer were treated by high-dose chemotherapy supporting by autologous peripheral blood stem cell transplantation. High-dose chemotherapy (carboplatin 250 mg/m2 or nedaplatin 200 mg/m2, etoposide 1,500 mg/m2, ifosphamide 7.5 g/m2 was given and peripheral blood stem cell transfusion was performed 72 hours after the last dose of chemotherapy. High-dose chemotherapy. was given followed by 1 or 2 cycles of pre high-dose therapy consisting of cisplatin 100 mg/m2 or carboplatin 500 mg/m2, etoposide 450 mg/m2, ifosphamide 6 g/m2. All 4 patients were evaluable. Three patients obtained a complete response and one showed a partial response. The partial responder was given RPLND. The RPLND specimen showed necrotic tissue.

[A case of life-threatening ventricular arrhythmias probably due to psychotropic drugs]

We present a case provoked life-threatening ventricular arrhythmias probably due to psychotropic drugs. The patient was a 55-year-old man who had previously twice operations of aortic valve replacement (AVR). The signs of cardiac failure were recurrently appeared from the end of 1991, and he had received promethazine and sulpiride for his depressive state. From cardiac catheterization, we planned his third AVR. The electrocardiographic (ECG) QTc interval was prolonged to 0.48 seconds on this admission. In March 1992 syncopal attack appeared suddenly, and his monitor ECG revealed frequent polymorphous ventricular tachycardia (VT) and Torsade de Pointes (Tdp). These arrhythmias stopped by emergent cardiac pacing. After discontinuing these psychotropic drugs, no ventricular arrhythmias appeared. Since the patient complained severe insomnia one month before operation, the diminished dose of psychotropic drugs (promethazine and levomepromazine) was readministered. Ten days after the operation, syncopal attack reappeared and his ECG recorded frequent VT and Tdp. During both syncopal attacks his serum potassium and magnesium were within normal limits. Two days later, he died from multi-organ failure. We concluded that life-threatening arrhythmias such as VT and Tdp might develop under the administration of mild psychotropic drugs (promethazine or levomepromazine), therefore, must better take a care of ECG changes in cases of using any psychotropic drugs.