Bone marrow stem cells in the infarcted heart

beta-Blockers in sepsis: reexamining the evidence

Sepsis remains the leading cause for noncardiac intensive care unit deaths in the United States. Despite recent advances in the treatment of this devastating condition, mortality and morbidity remain unacceptably high. Sepsis is characterized by a multitude of pathophysiological changes that include inflammation, metabolic derangements, hemodynamic alterations, and multiorgan dysfunction. Unfortunately, several studies of treatment modalities aimed at correcting one or more of the underlying derangements have led to disappointing results. New treatment modalities are needed. beta-Receptor blockers have long been used for a variety of conditions such as coronary artery disease, congestive heart failure, and arterial hypertension. Recent data suggest that beta-blocker effects on metabolism, glucose homeostasis, cytokine expression, and myocardial function may be beneficial in the setting of sepsis. Although treating a potentially hypotensive condition with a drug with antihypertensive properties may initially seem counterintuitive, the metabolic and immunomodulatory properties of beta-blockers may be of benefit. It is the purpose of this review to discuss the effects of beta-blockers on the following: (1) metabolism, (2) glucose regulation, (3) the inflammatory response, (4) cardiac function, and (5) mortality in sepsis.

Evaluation of the effect of autologous mesenchymal stem cell injection in a large-animal model of bilateral kidney ischaemia reperfusion injury

OBJECTIVES

Adult mesenchymal stem cells (MSC) have been proven to be of benefit to the kidney in different experimental models of renal injuries. All studies have been performed in valuable rodent models, but the relevance of these results to large mammals and ultimately, to humans remains unknown. Therefore, the aim of this study was to investigate the effect of MSC transplantation in an alternative ovine large-animal model of bilateral kidney ischaemia reperfusion injury.

MATERIAL AND METHODS

Sheep were divided into three groups: one sham-operated group and two groups submitted to renal bilateral ischaemia for 60 min. Animals with ischaemia reperfusion injury were treated with injection of autologous MSCs or with vehicle medium.

RESULTS

The model sheep presented with renal histological manefestations that closely resembled lesions seen in patients. Transplanted MSCs were found in glomeruli but not in tubules and did not express glomerular cell markers (podocin, von Willebrand factor), but functional evaluation showed no beneficial effect of MSC infusion. Morphological and molecular analyses corroborated the functional results. MSCs did not repair kidney parenchyma and failed to modulate cell death and proliferation or cytokine release (tumour necrosis factor-alpha, vascular endothelial growth factor alpha (VEGF-alpha), Bcl-2, caspase).

CONCLUSION

In this unique autologous large-animal model, MSCs did not exhibit reparative or paracrine protective properties.

Adipose tissue stromal cells transplantation in rats of acute myocardial infarction

OBJECTIVE

This study was to investigate the proliferation and differentiation of rat adipose stromal cells when implanted into ischemic myocardium and the improvement of heart function.

METHODS

Sprague-Dawley rat adipose tissue was digested with collagenase type I solution and adipose stromal cells were derived by culture. The cells' surface phenotype was examined by flow cytometry. Adipose stromal cells labeled with 4'6-diamidino-2-phenylindole (adipose stromal cells group) or Dulbecco's modified Eagle medium (control group) was transplanted into the ischemic myocardium, which was produced by ligation of left descending branch of coronary artery. At 1 and 4 weeks after transplantation, specimens were acquired from infarcted area and also echocardiography was done to detect the effects on heart function. Then, cell morphology and capillary density were measured, and vascular endothelial growth factor expression levels were assayed by reverse transcription-PCR and enzyme-linked immunosorbent assay.

RESULT

Adipose stromal cells derived by culture expressed CD44 and CD90 but not CD31 or CD45. Adipose stromal cells were alive at 1 and 4 weeks after transplantation and had a trend toward differentiation into vascular endothelial cells. The number of capillary vessels in peri-infarct area in adipose stromal cells group increased significantly compared with control group (P<0.01). The levels of vascular endothelial growth factor mRNA and protein expression at 1 week increased significantly in adipose stromal cells group compared with control group (P<0.01). Left ventricular function, including ejection fraction and fractional shortening, was higher in adipose stromal cells group when compared with control group at 4 weeks (P<0.01).

CONCLUSION

Adipose stromal cells transplantation can accelerate angiogenesis in infarcted area after rat myocardial infarction and can improve heart function.