ABSTRACT
Aim To explore the effect of N-acetyl-L-cysteine ( NAC ) on β amyloid peptide 25 - 35 ( Aβ25-35 )-induced the increase of calpain activity and its possible mechanism. Methods The activity of cal-pain was induced by 20μmol·L-1 Aβ 25-35 in primary cortical neuron. Neurons were incubated in the absent or present Aβ25-35 , or pre-incubated NAC ( 10 mmol ·L-1 ) , then co-incubated with Aβ25-35 . The meas-urement of calpain activity, H2 O2 level and mitochon-drial membrane potential was performed on a micro-plate fluorometer. The ATP level was detected using a luciferin/luciferase based ATP assay kit. Results In Aβ25-35 treated group, the activity of calpain and H2 O2 was obviously higher than that in control group. How-ever, in neurons pre-incubated in NAC and then co-in-cubated in Aβ25-35 , the calpain activity and H2 O2 level were significantly decreased compared with that in Aβ25-35 group. Upon Aβ25-35 exposure for 12 h, corti-cal neurons showed a significant decrease in mitochon-drial membrane potential and ATP level when com-pared to the control group. Pre-treatment with NAC showed an increase in mitochondrial membrane poten-tial and ATP level as compared to neurons treated with Aβ25-35 alone for 12h. Conclusion This result sug-gests that NAC can attenuate calpain activity induced by Aβ25-35 through protecting mitochondria.
ABSTRACT
The probable mechanism of the reduction of rat cerebral ischemic-reperfusion injury by propyl gallate was studied. Intraluminal suture middle cerebral artery occlusion model of rat was employed. Propyl gallate was injected immediately after the ischemia was happened. The activity of NF-kappaB, and the expression of COX-2 and HSP70 on the peripheral ischemia were determined by Western blotting. The expression of TNF-alpha was determined by ELISA assay. RT-PCR and immunofluorescence staining were employed to detect the transcription and expression of TLR-4. Results showed that propyl gallate could inhibit the activity of NF-kappaB in the peripheral ischemia, and reduce the expression of COX-2 and TNF-alpha. As the upstream of NF-kappaB, the transcription and expression of TLR-4 decreased, as well as HSP70, the endogenic ligand of TLR-4. As an antioxidant, propyl gallate could reduce the cerebral ischemic-reperfusion injury through inhibiting the activity of NF-kappaB and decreasing the COX-2 and TNF-alpha in the peripheral ischemia. It also could influence HSP70 and TLR-4.
ABSTRACT
Objective To search for the methods of inducing the high stability rat middle cerebral artery occlusion (MCAO) model and to noninvasively assess the method of model effect. Methods Six kinds of filaments with different diameters were used to induce rat MCAO models and their success rate, incidence of subarachnoid hemorrhage, and infarct volume were compared. The model scores were performed to assess the model effect after the operation and at 24 hours after reperfusion. Results Higher model success rate and lower incidence of subarachnoid hemorrhage were achieved when the 0. 28 mm in diameter and 0.32-0.34 mm in tip diameter filaments were used. 1he sensibility and specificity were higher when the model scores were performed at 24 hours after reperfusion. Conclusions Using the filaments of 0.28 mm in diameter and 0. 32-0. 34 mm in tip diameter for intraluminal thread could improved the stability of the models. The model scores at 24 hours after reperfusion could noninvasively assess the model effect.
ABSTRACT
<p><b>OBJECTIVE</b>To assess the level of alpha-fetoprotein (AFP) messenger RNA (mRNA) in peripheral blood of nude mice, and to study its relationship with tumor recurrence and metastasis after curative resection of hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>The metastatic model of human HCC in nude mice LCI-D20 was used in this study. Curative resection was performed at 10th day after tumor implantation in 28 nude mice. Interferon alpha-1b (IFN alpha-1b) was administered subcutaneously from the next day after resection, at doses of 3 10(7)U/kg/d (8 nude mice), 1.5 10(7) U/kg/d (8 nude mice) respectively in the treatment groups, and normal saline alone in the controlled group (12 nude mice). Thirty-five days after treatment, one milliliter of peripheral blood was taken and AFP mRNA was quantitatively analyzed using TaqMan real-time quantitative RT-PCR. The mice were sacrificed. The size of recurrent tumor was measured and the presence of lung metastases was observed.</p><p><b>RESULTS</b>The liver recurrent rate, lung metastatic rate and positivity of AFP mRNA in the controlled group were all 100% (12/12), whereas it was 62.5% (5/8), 0% (0/8), 87.5% (7/8) respectively in the IFN alpha-1b 1.5 10(7)U/kg/d treated group. The recurrent tumor in liver of the IFN alpha-1b 1.5 10(7)U/kg/d treated group was much smaller than that of the controlled group (25 mm(3) 2 mm(3) vs 1143 mm(3) 3 mm(3), t =9.27, P<0.01), and the level of AFP mRNA was also lower than that of the controlled group [(85 6)copies/mug vs (955 2) copies/mug, t =4.33, P<0.01]. In the IFN alpha-1b 3 10(7)U/kg/d treated group, there was only one recurrent tumor (0.5 mm(3)), no lung metastasis, and the positivity of AFP mRNA was 0% (?(2)=11.67, P<0.01).</p><p><b>CONCLUSIONS</b>These results suggest that the level of AFP mRNA in peripheral blood may indicate recurrence and/or metastasis after curative resection of HCC. TaqMan real time quantitative RT-PCR is a very sensitive and convenient method for detecting circulating cancer cells.</p>