RESUMO
@#Objective To investigate the optimal administration combination of β-aminopropionitrile (BAPN) and Angiotensin Ⅱ (Ang-Ⅱ) in the establishment of SD rat aortic dissection (AD) model and the related complications. Methods Forty-two three-week-old male SD rats were randomly divided into 7 groups: a group A (0.25% BAPN), a group B (0.40% BAPN), a group C (0.80% BAPN), a group D [1 g/(kg·d) BAPN], a group E [1 g/(kg·d) BAPN+ 1 μg/(kg·min) saline], a group F [1 g/(kg·d) BAPN+1 μg/(kg·min) Ang-Ⅱ] and a group G (control group). There were 6 rats in each group. The intervention period was 4 weeks (groups E and F were 4 weeks+5 days). Rats were dissected immediately if they died during the experiment. After the intervention, the surviving rats were sacrificed by pentobarbital sodium, and the whole aorta was separated and retained. Hematoxylin-eosin staining was used to observe the changes of aorta from the pathological morphology. Results There was no statistical difference in the survival rate among the groups after 4 weeks of BAPN intervention (P>0.05). After 5 days of mini-osmotic pumps implantation, the survival rate of rats was higher in the group E than that in the group F (P=0.008), and the incidence of AD in the group E was lower than that in the group F (P=0.001). BAPN could affect the food and water intake of rats. After BAPN intervention for 4 weeks, the body weight of rats in the group G was higher than those in the intervention groups (P<0.05). BAPN combined with Ang-Ⅱ could make the aortic intima thick, elastic fiber breakage, arrangement disorder, and inflammatory cell infiltration in rats, which conformed to the pathological and morphological changes of AD. BAPN could also affect mental state and gastrointestinal tract. Conclusion The combination of BAPN [1 g/(kg·d)] and Ang-Ⅱ [1 μg/(kg·min)] can stably establish AD model in rats, which will provide a stable carrier for further study of the pathogenesis and therapeutic targets of AD. However, the complications in this process are an unstable factor. How to balance the influence of BAPN on other tissues and organs in the process of AD model establishment remains to be further studied.
RESUMO
Penicillium decumbens T. is an important filamentous fungus for the production of cellulases to effectively degrade lignocellulose for second generation biofuel production. In order to enhance the capability of Penicillium decumbens to produce cellulases, we constructed a creB (a deubiquitinating enzyme encoding gene) deletion cassette, and generated a creB knockout strain with homologous double crossover recombination. This mutation resulted in a detectable decrease of carbon catabolite repression (CCR) effect. The filter paper activity, endoglucanase activity, xylanase activity and exoglucanase activity of the deltacreB strain increased by 1.8, 1.71, 2.06 and 2.04 fold, respectively, when comparing with the parent strain Ku-39. A 2.68 fold increase of extracellular protein concentration was also observed. These results suggest that the deletion of creB results in CCR derepression. These data also suggest that CREB influences cellulase production of Penicillium decumbens. In generation, this study provides information that can be helpful for constructing cellulase hyper-producing strain.