Regulation of the embryonic erythropoietic niche: a future perspective

The production of red blood cells, termed erythropoiesis, occurs in two waves in the developing mouse embryo: first primitive erythropoiesis followed by definitive erythropoiesis. In the mouse embryo, both primitive and definitive erythropoiesis originates in the extra-embryonic yolk sac. The definitive wave then migrates to the fetal liver, fetal spleen and fetal bone marrow as these organs form. The fetal liver serves as the major organ for hematopoietic cell expansion and erythroid maturation after mid-gestation. The erythropoietic niche, which expresses critical cytokines such as stem cell factor (SCF), thrombopoietin (TPO) and the insulin-like growth factors IGF1 and IGF2, supports hematopoietic expansion in the fetal liver. Previously, our group demonstrated that DLK1⁺ hepatoblasts support fetal liver hematopoiesis through erythropoietin and SCF release as well as extracellular matrix deposition. Loss of DLK1⁺ hepatoblasts in Map2k4(−/−) mouse embryos resulted in decreased numbers of hematopoietic cells in fetal liver. Genes encoding proteinases and peptidases were found to be highly expressed in DLK1⁺ hepatoblasts. Capitalizing on this knowledge, and working on the assumption that these proteinases and peptidases are generating small, potentially biologically active peptides, we assessed a range of peptides for their ability to support erythropoiesis in vitro. We identified KS-13 (PCT/JP2010/067011) as an erythropoietic peptide-a peptide which enhances the production of red blood cells from progenitor cells. Here, we discuss the elements regulating embryonic erythropoiesis with special attention to niche cells, and demonstrate how this knowledge can be applied in the identification of niche-derived peptides with potential therapeutic capability.

Diagnostic accuracy of neuropsychological tests for classification of dementia

Although numerous studies have shown that each neuropsychological test is effective for diagnosing mild cognitive impairment (MCI) or Alzheimer’s disease (AD), studies comparing diagnostic accuracies of various neuropsychological tests are relatively rare and practical cutoff values are not available. The present study aimed to investigate the validity of neuropsychological tests and develop cutoff values for each in differentiating healthy control (HC), MCI and AD groups. A total of 84 HC, 187 with MCI and 195 with AD were evaluated by the selected seven neuropsychological tests using receiver operating characteristic (ROC) curve analysis. Logical Memory (LM) delayed recall (cutoff, 7) and Rey Auditory Verbal Learning Test (RAVLT) delayed recall (cutoff, 6) were effective for differentiating HC from MCI. To distinguish MCI and AD, Rey Osterrieth Complex Figure Test (ROCFT) 3 mindelayed recall (cutoff, 6) and LM immediate recall (cutoff, 4) were excellent. Delayed recall of verbal materials, as indexed by LM and RAVLT was sensitive for discriminating MCI from HC. Handling visual memory traces, as indexed by ROCFT and immediate verbal information by LM were sensitive for differentiating MCI and AD.

Pulmonary alveolar hemorrhage from a pulmonary artery false aneurysm after Swan-Ganz catheterization in a thoracic aortic aneurysm patient: a case report / 대한마취과학회지

Pulmonary artery (PA) rupture caused by a PA Swan-Ganz catheter is a rare complication but remains fatal in almost 50% of cases. False aneurysm of the PA is a rare presentation of PA rupture and should be considered as a possible diagnosis in a patient with a new lung mass after PA catheterization. We present a case of sudden-onset pulmonary alveolar hemorrhage during cardiovascular surgery due to a traumatic PA false aneurysm. The Swan-Ganz catheter might have been displaced by the thoracic aortic aneurysm with displacement of the catheter causing the false aneurysm and bleeding.