[Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults].

Objective: To explore the normal ranges of perfusion parameters between cerebral hemisphere, cerebellar hemisphere and brain anatomical subregions (56 pairs) in different gender and age groups with multiple post labeling delay time (Multi-PLD) arterial spin labeling (ASL) imaging. Methods: From November 2020 to December 2020, 42 healthy adult volunteers (Male 25, Female 17) were recruited to perform 7 PLD ASL imaging, including 21 young adults (15 males and 6 females, aged 23-35 years) and 21 seniors (10 males and 11 females, aged 36-74 years). The data was processed offline by Cereflow software to obtain arterial arrival time (ATT) and corrected cerebral blood flow (CBF) and cerebral blood volume (CBV) perfusion parameters. SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling (AAL) template. Therefore, CBF, ATT, CBV perfusion values of brain subregions were obtained. Paired samples t test, Wilcoxon rank sum test, independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere, the cerebellar hemisphere, brain subregions depending on side, gender and age. Pearson correlation analysis was used to compare the correlations of perfusion parameters with age. Results: CBF in 62.5% (35/56) subregions and CBV in 44.6% (25/56) subregions were higher in right side than those in left side. ATT in most brain anatomical subregions (16/56) were higher in left side. The CBF [(35.30±8.31) vs. (34.34±7.53) ml·100g-1·min-1, P=0.021], CBV [(0.47±0.11) vs. (0.45±0.09) ml/100g, P<0.001], ATT [(1.30±0.10) vs. (1.24±0.11) s, P<0.001] in left cerebellar hemisphere were higher than that of right side. The CBF (28/56) of cerebral hemisphere, cerebellar hemisphere and brain subregions was higher in females than that in males, while ATT in 83.9% (47/56) subregions was lower than that in males (all P<0.05). CBV in female subjects was higher only in 5 brain regions (superior occipital gyrus, middle occipital gyrus, inferior occipital gyrus, superior parietal gyrus and cerebelum_7b) (all P<0.05). In young subjects, CBF in 44.6% (25/56) subregions and CBV in 33.9% (19/56) subregions were higher than those in the senior group (all P<0.05). The ATT in most subregions in young group were lower than those in senior group, but the difference was statistically significant only in rectus gyrus (P=0.026) and paracentral lobule (P=0.006). The CBF (r=-0.430, P=0.005) and CBV (r=-0.327, P=0.035) of cerebral hemisphere were negatively correlated with age. The CBF (24/25, r range:-0.497 --0.343, all P<0.05) and CBV (16/19, r range:-0.474 --0.322, all P<0.05) in most subregions were negatively correlated with age, while ATT was positively correlated (gyrus rectus: r=0.311, P=0.045; paracentral lobule: r=0.392, P=0.010). Conclusions: Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion. The perfusion parameters of anatomical subregions are different depending on side, gender, and age.

Effect of treating renal failure with decorin gene therapy.

OBJECTIVE: To explore a new approach for treating renal insufficiency with gene therapy by implanting decorin (DCN)-expressing fibroblasts within the renal tissue of rats with renal failure to neutralize TGF-ß1 activity. MATERIALS AND METHODS: The 5/6 kidney of the selected male SD rats were removed under aseptic conditions. The rats were grouped randomly after the establishment of the model. There were 10 rats in the sham-operated group (Group A), 10 in the operation control group (without treatment, Group B), 10 in the blank control group [treated with empty vector-transfected fibroblasts (FB (LXSN) cells), Group C], and 10 in the treatment group [treated with FB (LDCNSN) cells, Group D]. The pathological changes of rats including body weight, blood lipids, renal function, and renal histology, were observed. The expression of TGF-ß1 and DCN in renal tissue was detected by immunohistochemistry. RESULTS: There were no significant differences in body weight and blood lipids between the groups at 4 weeks after treatment. The levels of blood urea nitrogen and serum creatinine in rats in Group D were significantly decreased compared with those in Group C (p < 0.05). Although the differences were not statistically significant, the levels of those pathological indicators are higher than baseline values. The expression of DCN in renal tissue increased significantly after 4 weeks in rats of Group D and the differences were significant compared with the other groups. There were no significant differences in TGF-ß1 expression between any two groups of Group D, B, and C. Furthermore, pathological damage to the renal interstitium of rats in Group D was significantly decreased compared with that of Group B and C. CONCLUSIONS: DCN can alleviate fibrosis and delay the progression of renal failure.