[Role of Rictor in Hematopoietic Stem Cells during Fetal Liver Hematopoiesis].

OBJECTIVE: To investigate the effect of Rictor on the hematopoiesis of fetal liver by specific knock-out of Rictor in hematopoietic cells of Vav-Cre mice. METHODS: E12.5 0.08ee fetal liver cells from the experimental group Vav-Cre; Rictorf/f embryos and control group Rictor f/+ or Rictorf/f embryos were transplanted to recipients respectively to observe the effect of Rictor on reconstitution ability of hematopoietic stem cells. In the meantime, E14.5 0, 10, 20, 40, 60, 80 sorted hematopoietic stem cells from the Vav-Cre; Rictorf/f fetal liver of experimental group and Rictorf/+ or Rictorf/f fetal liver of control group were transplanted in to recipients to analyze the numbers of functional hematopoietic stem cells after Rictor was knocked-out. Furthermore, the self-renewal capacity was investigated by secondary transplantation of BM cells from primary recipients that had been successfully repopulated with E12.5 fetal liver-derived cells and by cell cycle analysis. RESULTS: All the recipients receiving E12.5 Rictorf/+ or Rictorf/f cells were repopulated (8/8, from 2 independent experiments) with an average chimerism of 77.2%±11.1% at 4 months post-transplantation, which resulted in 57 LT-RU per FL. In comparison, 8 out of 8 recipients receiving Vav-Cre; Rictorf/f cells were repopulated with significantly reduced chimerism (37.0%±16.3%) (P＜0.01), which was equivalent to 8 LT-RU per FL. The limiting dilution transplantation experiment showed that there was one functional hematopoietic stem cell out of 17 sorted SLAM cells in the control group, and one functional hematopoietic stem cell out of 39 sorted SLAM cells in the experimental group. The secondary transplantation experiments showed that 2 out of 4 recipients were reconstructed in the control group after 1 month, and 0 was reconstructed in the experimental group by transplanting 4×105 donor cells respectively. What＇s more, the percentage of S/G2/M cells in the experimental group increased when compared with controls. CONCLUSION: In the process of fetal liver hematopoiesis, the specifically knocking-out the Rictor in hematopoietic system can lead to defect of reconstitution ability, decrease of the functional hematopoietic stem cell numbers and reduction of self-renewal ability of hematopoietic stem cells.

Late onset radiation-induced constrictive pericarditis and cardiomyopathy after radiotherapy: A case report.

INTRODUCTION: Radiation-induced heart disease (RIHD) is a serious side effect of cancer treatment, including coronary artery disease, valvular cardiac dysfunction, cardiomyopathy, aortopathy, and chronic constrictive pericarditis. Herein, this case we present was diagnosed as radiation-induced constrictive pericarditis and cardiomyopathy by means of cardiac magnetic resonance (CMR) and transthoracic echocardiogram, finally confirmed by pathology after performing heart transplant operation. CONCLUSIONS: This case supports a notion that RIHD often causes multiple heart impairment and CMR is helpful to diagnose cardiomyopathy after radiation.

[Clinical characteristics of 22 cases of fungal infective endocarditis].

OBJECTIVE: To explore the clinical characteristics, treatment regimens and outcomes of the patients with fungal infective endocarditis. METHODS: An observational study was conducted at our hospital and recruited 22 consecutive patients with a definite diagnosis of fungal infective endocarditis. Their overall characteristics, treatments, complications and outcomes were analyzed. RESULTS: The mean age at presentation was 45 years with a slight male preponderance. Among them, 13 cases had healthcare-associated infective endocarditis and 1 patient was an intravenous drug user. Aortic valve (40.9%) was most commonly affected and it was followed by mitral valve (13.6%). The most common etiological agent was Candida (68.2%), followed by Aspergillus (22.7%). Risk factors include the prosthetic valve replacement surgery, impaired immune function, and so on. Major complications during the acute infective phase were also recorded, including heart failure, embolic events, uncontrolled infections and renal dysfunction. The overall hospital mortality rate was 40.9%. There were 15 patients with antifungal treatment, which including fluconazole, itraconazole, caspofungin acetate and voriconazole itraconazole. The remaining 7 patients (31.8%) underwent valve replacement surgery, including 3 cases of cardiac valve re-replacement. A better outcome was observed in patients on a combined regimen of medical and surgical therapies. CONCLUSIONS: Fungal endocarditis is associated with more invasive interventions and immunocompromised patients. The incidence of embolic events and in-hospital mortality is still high in patients with fungal endocarditis, and the larger vegetation is more common. Heart failure, sepsis and repeated arterial embolization are the most common cause of death.

Comparison of characteristics and short-term outcome from fungal infective endocarditis in prosthetic valve endocarditis versus native valve endocarditis.

Fungal infective endocarditis (IE) is a rare, serious, and potentially lethal disease, yet its clinical characteristics and short-term outcomes remain poorly understood. A detailed comparative analysis of fungal prosthetic valve endocarditis (PVE) and native valve endocarditis (NVE) has not been performed. This study was designed to explore the general characteristics, treatment patterns, and outcomes of patients with fungal IE in a Chinese hospital and compare these data between PVE and NVE. Four hundred ninety-three patients were admitted to Fuwai hospital from January 2002 to December 2010. Fungal IE accounted for 7% (32 cases) of cases. Of these patients, 19 (59%) patients had NVE, 12 (37%) PVE, and 1 (3%) cardiac device-related infective endocarditis (CDRIE). Candida albicans remained the predominant causative pathogen (47% of all IE). Patients with NVE, compared with PVE patients, were older (50 years vs 37 years, p = 0.034), had less frequent history of previous endocarditis (0 vs 25%, p = 0.049), and were more likely to have a history of diabetes (37% vs 0, p = 0.026) and be in an immunocompromised state (37% vs 0, p = 0.026). Nearly half of the patients died of refractory heart failure, followed by severe sepsis and stroke. In-hospital mortality rate was 38%, and the 3-month cumulative mortality rate was 47%. Recurrence of IE was more common in fungal PVE patients (42% vs 5%, p = 0.022) during the 90-day follow-up. In conclusion, fungal IE is associated with high mortality and recurrence rates. Surgery performed in selected cases may improve the outcomes, but the recurrence rate remains high.