Three-dimensional-arterial spin labeling perfusion correlation with diabetes-associated cognitive dysfunction and vascular endothelial growth factor in type 2 diabetes mellitus rat.

BACKGROUND: Type 2 diabetes mellitus (T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia. The mechanisms of diabetes-associated cognitive dysfunction (DACD) have not been fully elucidated to date. Some studies proved lower cerebral blood flow (CBF) in the hippocampus was associated with poor executive function and memory in T2DM. Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor (VEGF) expression and CBF changes in humans and animal models. In this study, we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional (3D) arterial spin labeling (3D-ASL) and VEGF expression in the hippocampus. AIM: To assess the correlation between CBF (measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM. METHODS: Forty Sprague-Dawley male rats were divided into control and T2DM groups. The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM. Cognitive function was assessed using the Morris water maze experiment. The CBF changes were measured by 3D-ASL magnetic resonance imaging. VEGF expression was determined using immunofluorescence. RESULTS: The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group. The total distance traveled was longer in the T2DM group; also, the platform was crossed fewer times. The percentage of distance in the target zone significantly decreased. CBF decreased in the bilateral hippocampus in the T2DM group. No difference was found between the right CBF value and the left CBF value in the T2DM group. The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value. The escape latency negatively correlated with the CBF value. The number of rats crossing the platform positively correlated with the CBF value. CONCLUSION: Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD. CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.

[Anatomical study of improved lateral arm free flap].

OBJECTIVE: To study the anatomy and preparation methods of an improved lateral arm free flap (LAFF) for the future clinical application. METHODS: Twenty-two adult upper extremities from cadavers after injected with red latex through common carotid arteries were used. The course, branches, distribution and variations of the blood vessels and nerves of the improved LAFF were observed. The outer diameters of the vessels were measured. RESULTS: The mean length of vascular pedicle of the improved LAFF was (14.85 ± 1.28) cm, significantly more than that (5.46 ± 2.60) of traditional LAFF (t = -8.483, P < 0.001). The mean outer diameters of pedicle arteries and veins in the improved LAFF were (2.24 ± 0.66) mm and (2.22 ± 0.52) mm, significantly more than those (1.15 ± 0.21 and 1.26 ± 0.23) in traditional LAFF (t = -8.690, P < 0.001; t = -15.057, P < 0.001), respectively. CONCLUSION: The improved LAFF has a longer vascular pedicle and larger artery and vein in diameter than conventional LAFF, and is more suitable for the repair of the small and medium-sized defects of the head and neck.

[Expression and clinical significance of P-gp in colonic gland of chronic schistosomiasis patients].

OBJECTIVE: To study the expression of P-glycoprotein (P-gp) in patients with chronic schistosomiasis and its relationship with gender and age, and to explore its clinical significance. METHODS: The colonic mucosa specimens of 50 chronic schistosomiasis patients and 4 persons who had a family history of colon cancer but their physical examinations were normal (as a control group) were selected and the expressions of P-gp in the colonic gland of these samples were detected with the immunohistochemical staining method. RESULTS: Compared with the control group, the mean gray value of the positive particles of P-gp of colonic epithelial cells of the chronic schistosomiasis group was significantly reduced (P < 0.05), but positive unit values were significantly increased (P < 0.05), which meant the P-gp expression in colonic gland of the patients with chronic schistosomiasis was significantly increased, but this increase had no relationship with sex and age. CONCLUSION: Chronic schistosomiasis may induce the increase of P-gp expression which may be a compensatory protection mechanism due to the stimulation of schistosome eggs to the colon tissues.

[Endogenous BDNF promote regeneration of injured nervous system].

OBJECTIVE: To test the effect of endogenous BDNF on injured nervous system. METHODS: The left sciatic nerves of the rats were cut off, and then divided into two groups, each with 8 rats. The rats in the experimental group were intraperitoneally injected with anti-BDNF, while the control group was given normal sheep serum (NSS). The dorsal coclums of the rats were cut on the 8th day. The L5 DRG were cut into length wise sections to dye with fluorescent antibody. Positive cells of GAP-43 in the L5 DRG were counted. The second experiment had both sides of sciatic nerves of the rats cut off, followed by the same procedure as the first experiment. The HRP tracing and ABC immunohistochemical staining were performed to analyse the effect of endogenous BDNF on the recovery of injured spinal cords. RESULTS: For the rats with left sciatic nerves cut off, the experimental group had less GAP-43 positive cells in the left L5 DRG than the controls (P<0.01). For the rats with both sciatic nerves cut off, the experimental group had less nerves with positive fibers-labeled HRP than the controls at the site of tSCI (P<0.01). CONCLUSION: Endogenous BDNF promote the recovery of injured nervous system.