New-onset lesions on MRI-DWI and cerebral blood flow changes on 3D-pCASL after carotid artery stenting.

This study aimed to investigate the relationship between the new-onset hyperintense lesions on diffusion-weighted images (DWI) and the changes of cerebral blood flow (CBF) before and after carotid artery stenting (CAS) in patients with symptomatic unilateral carotid artery stenosis. Twenty-four patients with symptomatic unilateral carotid stenosis (50-99%) were enrolled. Routine head magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling were taken 7 days before the surgery and for four consecutive days post CAS. While the incidence of new DWI lesions were high (17/24, 70.8%) and 176 lesions were observed among the 17 cases, there was only one subject showing the symptoms. The majority of the lesions were located at the cortex/subcortex of the ipsilateral frontal and parietal lobes (60.8%) with 92.6% of the lesions size being less than 3 mm. The CBFs in this area were significantly higher than that of the temporal lobe on the first 3 days post stenting (p < 0.05). No periprocedural CBF differences were observed between the two groups, however, the micro-embolism group presented decreased relative CBF in frontal and parietal lobes prior to stenting compared with the non-embolism group. The systolic blood pressure in the micro-embolism group at discharge was significantly lower than that at admission. The high incidence rate of micro-embolism in patients receiving CAS may not be the result of direct changes of hemodynamics in the brain but rather the loss of CBF regulation due to long-term hypoperfusion prior to the stenting.

[Expression and effect of neuropilin-1 in acute myeloid leukemic cells].

This study was aimed to investigate the expression of neuropilin-1 (NRP-1) and NRP-2 mRNA in myeloid leukemia cells and the effect of NRP-1 on cell proliferation and migration. The expressions of NRP-1 and NRP-2 mRNA in bone marrow mononuclear cells of 24 patients with acute myeloid leukemia and in 7 myeloid leukemic cell lines (HL-60, KGIa, NB4, U937, HEL MEG01 and K562) were detected by RT-PCR. The effects of NRP-1 interfered with siRNA on proliferation and migration in leukemic cell line HEL were examined by MTT and migration test. The results showed that the expression of NRP-1 mRNA was found in bone marrow mononuclear cells (BMMNCS) of 24 AML patients, the positive rate was 100% and significantly higher than that in control group (positive rate 67%). The expressions of NRP-2 mRNA were seen in 79% AML patients and in 67% health control, there was no significant difference between them. The increased NRP-1 expression was directly correlated with the blast percentage in both peripheral blood and bone marrow of AML patients (r=05, r=0.4, p<0.05). The expressions of NRP-1 and NRP-2 mRNA were observed in 6/7 and 3/7 myeloid leukemic cell lines respectively. After HEL cells were transfected with siRNA for 24 hours, the expression levels of NRP-1 mRNA and protein decreased obviously. Under VEGF action, the cell number in control group significantly increased, while the cell proliferation in interfered group had been not changed. After being transfected for 24 hours, the migration in interfered group decreased significantly. It is concluded that the higher level of NRP-1 mRNA is expressed in bone marrow mononuclear cells of leukemia patients and plays a pivotal role in proliferation and migration of myeloid leukemic cells. Inhibition of NRP-1 functions may provide a new therapeutic strategy for AML.

Human umbilical cord blood cells express neurotrophic factors.

Freshly isolated or culture-expanded human umbilical cord blood mononuclear cells (CBMNCs) have been known to express neural phenotypes in vitro and to differentiate into neural cells and improve neurological function recovery after being administrated into rodent models of neurological diseases. However, the mechanism of action remains unclear. The present study observed that CBMNCs expressed higher level mRNAs of several neurotrophic factors than adult peripheral blood mononuclear cells (PBMCs). In addition, a significantly increase in the levels of brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT4/5) was found in culture supernatants of CBMNCs compared to that of PBMNCs. These findings indicate that CBMNCs express several neurotrophic factors and suggest that the neurotrophic factors secreted by CBMNCs may be responsible for amelioration of central nervous system deficits in animal models after CBMNC administration.