Endovascular stent-graft repair of a tuberculous mycotic aortic aneurysm

Mycobacterium tuberculosis is a rare cause of mycotic aortic aneurysms, which have been classically treated with a combination of antimycobacterial medical therapy and open surgery. Endovascular therapy has been gaining popularity as an alternative to open surgery for mycotic aneurysms. We report a case of a tuberculous mycotic aneurysm of the descending thoracic aorta that was successfully treated with endovascular stent-graft placement with complete resolution of the pseudoaneurysm at 1 year. We also review other cases in the previously published data to identify factors that may affect the outcome of endovascular treatment of tuberculous mycotic aneurysms.

Enrichment of a bipotent hepatic progenitor cell from naïve adult liver tissue

BACKGROUND/AIM

Recent interest in the liver stem cell field has led to the identification and characterization of several hepatic progenitor cell populations from fetal and adult tissues. We isolated a hepatic progenitor cell from naïve adult liver and the current studies focus on differentiation and growth.

RESULTS

A Sca-1(+) hepatic progenitor cell was identified within the liver parenchyma. This cell expresses numerous liver related genes and transcription found in the developing and/or adult liver. It is located in the peri-portal region and expresses markers associated with undifferentiated hepatic cell populations, mature hepatocytes and biliary cells which distinguish it from the Sca-1(-) fraction.

CONCLUSION

This hepatic progenitor cell from uninjured liver has features of both hepatocytic and biliary populations and demonstrates proliferative potential. Further studies will focus on sca-HPC subsets and conditions that regulate differentiation towards hepatic or biliary lineages.

Hepatic Stem Cells: In Search of

The field of stem cell biology has exploded with the study of a wide range of cellular populations involving endodermal, mesenchymal, and ectodermal organs. One area of extensive study has included the identification of hepatic stem and progenitor cell subpopulations. Liver stem cells provide insights into the potential pathways involving liver regeneration that are independent of mature hepatocytes. Hepatic progenitor cells are either bipotent or multipotent and capable of multiple rounds of replication. They have been identified in fetal as well as adult liver. Various injury models have been used to expand this cellular compartment. The nomenclature, origin, and function of the hepatic progenitor cell populations are areas of ongoing debate. In this review, we will discuss the different definitions and functions of hepatic progenitor cells as well as the current research efforts examining their therapeutic potential.