The use of rat brain slices as an in vitro model for mechanistic evaluation of neurotoxicity-studies with acrylamide

Biochemical mechanisms underlying acrylamide induced neurotoxicity were examined using an in vitro model consisting of sagittal slices of rat brain. Incubation of brain slices under oxygen in artificial cerebrospinal fluid containing acrylamide produced a dose and time dependent inhibition of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Lysosomal enzymes, acid phosphatase, N-acetyl glucosaminidase and beta-glucuronidase decreased in a similar manner, while no changes were observed in the activity of Na+K+ATPase, cytochrome c oxidase and lactate dehydrogenase. Incubation of slices with two structurally related compounds, acetamide (a non-neurotoxic amide) and methylene bis-acrylamide (a weak neurotoxin), indicated that acrylamide selectively inhibited GAPDH, enolase and N-acetyl glucosaminidase at low concentration; similar doses of acetamide and methylene bis-acrylamide did not have the same effect on brain slices. Incubation with acrylamide depleted glutathione levels in slices, and the addition of glutathione to the incubation medium prevented acrylamide induced inhibition of GAPDH and lysosomal enzymes. Time dependent inhibition of lysosomal enzymes was also observed in vivo, in the brain and sciatic nerve of rats following a single dose of acrylamide. These results demonstrate that both in vitro and in vivo, lysosomal enzymes are also inhibited following acrylamide exposure. The rat brain slice model exhibits both selectivity and sensitivity towards neurotoxicants and hence, may prove to be an useful in vitro model for the mechanistic evaluation of neurotoxicity.     

钝性肝脾肾损伤的CT平扫与增强扫描比较

目的:比较CT平扫与增强扫描对肝脾肾钝性损伤的诊断能力。方法:回顾性分析临床疑似钝性肝脾肾损伤,并经手术和临床观察证实的CT平扫和增强扫描的患者84例。结果:平扫确定的损伤:肝12例,脾25例,肾5例;平扫可疑损伤:肝22例,脾15例,肾5例。增强确定的损伤:肝32例,脾40例,肾12例(全肾梗塞1例,局限性梗塞3例);对比剂外溢(活动性出血)3例;无可疑损伤。平扫无异常而增强确定有损伤:肝10例,脾5例,肾2例。增强显示的损伤灶比平扫范围明显大、病灶多、界限清楚。结论:CT增强扫描显示肝脾肾损伤明显优于平扫,延时扫描有助于发现活动性出血,应常规增强扫描。     

Juvenile Xanthogranuloma with Ocular Involvement

Abstract:   Juvenile xanthogranuloma is a benign histiocytic skin disorder encountered primarily in infancy and childhood. Approximately 0.4% of cases exhibit ocular manifestations, which can result in glaucoma and blindness. We present a case of a 7-month-old male with unilateral glaucoma associated with Juvenile xanthogranuloma, and emphasize the importance of an ocular screening in patients with Juvenile xanthogranuloma, especially those with periocular lesions.     

5-羟色胺受体激动剂对脊髓损伤猫排尿功能的影响

目的探讨5-羟色胺(5-HT)受体激动剂对猫脊髓损伤后膀胱过度活动的影响。方法雌性猫18只,其中正常假手术组5只,脊髓损伤组13只。术后6~8周,氯醛糖麻醉下,在猫颈动脉及膀胱内置管,连接压力感受器,记录诱发膀胱收缩的膀胱容量阈值、膀胱容量、剩余尿量、排尿量和血压。静脉注入5-HT1A受体激动剂8-OH-DPAT(0.3~30μg/kg)或5-HT1B/1D受体激动剂GR-46611(0.03~300μg/kg),得到剂量-效应曲线后再给予5HT1A受体抑制剂WAY-100635(300μg/kg),比较给药前后各项指标变化。结果正常猫使用8-OH-DPAT后,膀胱容量阈值、膀胱容量、剩尿量均有增加趋势,但差异无统计学意义;8-OH-DPAT和GR-46611均能使脊髓损伤猫的膀胱容量阈值、膀胱容量、剩余尿量增加,且效应随着剂量增加而增加,差异有统计学意义。WAY-100635能抵消8-OH-DPAT的作用,但对GR-46611无影响。结论5-HT1A和5-HT1B/1D受体激动剂能改善慢性脊髓损伤后的膀胱过度活动,增加膀胱容量。     

64排螺旋CT冠状动脉造影与DSA的对照研究

目的:通过和冠脉造影对比,评价64排螺旋CT冠状动脉成像在冠状动脉狭窄中的临床应用价值。方法:28例患者同时行64排螺旋CT冠状动脉成像和有创性冠脉造影检查,依据AHA17段分段法,评价所有有效节段,并将两者进行对比。结果:冠脉造影显示阴性病例占7.1%(2例),单只病变占21.4%(6例),多支病变占71.4%(20例)。按节段分析,CT检出冠脉狭窄的敏感度,特异度,阳性预测值和阴性预测值分别为91.1%,94.6%,90.0和95.3%。结论:64排螺旋CT冠状动脉成像和传统的冠脉造影检查对检出正常冠脉节段以及狭窄节段具有很好的一致性。