鞘内注射吗啡加可乐定对切口痛大鼠脊髓背角蛋白激酶A催化亚单位表达的影响

Objective To observe the effect of intrathecal clonidine plus morphine on expression of protein kinase A (PKA) catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods Eighty male Sprague-Dawley rats were divided randomly into five groups: sham group, control group, pre-incisional morphine 2.5 μg group, pro-incisional clonidine 5 μg group and preincisional morphine 2.5 μg plus clonidine 5 lag group (n=16). lntrathecal catheter and the model of incisional pain were pro-duced according to Yaksh and Brennan's described method respectively. Changes of pain behavior were assessed by mechanical with-drawal threshold (MWT) and thermal withdrawal latency(TWL). The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistochemical method and western blotting analysis. Results Compared with sham group, MWT and TWL in control group were decreased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group (P<0.01). Compared with control group, MWT and TWL in pre-incision morphine 2 μg plus clonidine 5 lag group were increased significantly at 2 h after incision (P<0.01) and the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre-incision morphine 2 μg plus clonidine 5 μg group (P<0.01). However, MWT, TWL and the number of positive cells and pro-tein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre-incisional morphine 2.5 μg group and pre-incisional clonidine 5 μg group compared with control group. Conclusion lntrathecal clonidine significantly enhances the antinociceptive effect of intrathecal morphine in a rat model of incisional pain, which might be associated with inhibi-tion of the increased expression of PKA catalytic subunit in spinal cord.     

Raf-1 kinase,epidermal growth factor receptors,and mutant ras proteins in colonic carcinomas

Epidermal growth factor receptors (EGFR) andras mutations are known to play a significant role in controlling cell growth and tumor promotion. Both of them transmit mitogenic signals to the nucleus by activation of Raf-1 kinase. In this study, the expression of EGFR and mutant Ras proteins, and, for the first time, the expression, phosphorylation and kinase activity of Raf-1 kinase have been determined in paired samples of colorectal cancer and mucosa. The tumor and mucosa samples did not differ significantly with regard to Raf-1 kinase content and activity. A major difference between tumors and mucosa was found, however, in the phosphorylation of Raf-1. Most of the mucosa samples (13/20), but only 1/20 of the cancer samples, contained hyperphosphorylated Raf-1. EGFR were significantly (p=0.0025) decreased in the tumors. The decreased phosphorylation of Raf-1 in colonic carcinomas could be the result of activation of Raf-1 phosphatases or inactivation of kinases phosphorylating Raf-1. New forms of treatment based on EGFR overexpression do not seem to be suitable for the majority of colonic cancers.This work was supported by the state of Baden-Württemberg (Verbundforschungsprojekt: Aufklärung von Mechanismen der Tumorentstehung und Tumorabwehr).     

胆囊癌组织中NDPK／nm23的表达及意义

作者用免疫组化ＡＢＣ法对４１例胆囊癌标本核苷二磷酸激酶（ＮＤＰＫ，下同）／ｎｍ２３表达进行了测定，结果发现：ｎｍ２３在恶性肿瘤中的表达率明显高于良性病变（Ｐ＜０．０５）。ＮＤＰＫ／ｎｍ２３表达与胆囊癌组织的分化、局部浸润及淋巴转移密切相关（Ｐ＜０．０１）。ＮＤＰＫ／ｎｍ２３阳性患者生存中位数１２．２５个月，阴性患者６．５个月，两者存在显著差异（Ｐ＜０．０１），提示ｎｍ２３检测对预后有重要价值。     

Lines of Murine Oligodendroglial Precursor Cells Immortalized by an Activated neu Tyrosine Kinase Show Distinct Degrees of Interaction with Axons In Vitro and In Vivo

Replication-defective retroviruses expressing the t- neu oncogene, or a hybrid protein with the neu tyrosine kinase linked to the external region of the human epidermal growth factor receptor ( egfr-neu ), were used to establish lines of murine oligodendroglial precursor cells. Differentiation of the t- neu lines into myelin-associated glycoprotein (MAG)-positive oligodendrocytes was induced by dibutyryl cAMP, and the egfr-neu line showed limited differentiation in vitro upon withdrawal of epidermal growth factor. Cerebellar granule cell neurons expressed mitogens for the cell lines. Upon transplantation into demyelinated lesions, t- neu line cells engaged with the demyelinated axons whereas the egfr-neu line cells differentiated further and ensheathed the axons. These cell lines thus interact with neurons in vitro and in vivo and can be used as tools to define the molecules involved in different stages of neuron-glia interaction.     

Decreased expression of DMPK: correlation with CTG repeat expansion and fibre type composition in myotonic dystrophy type 1

Abstract Myotonic dystrophy type 1 (DM1) is an autosomal dominant disease caused by a trinucleotide repeatexpansion, cytosine-thymine-guanine (CTG)_n, in the 3′ untranslated region of a gene encoding the myotonic dystrophy protein kinase (DMPK). To correlate CTG expansion and protein expression, we studied muscle specimens from 16 adult DM1 patients using three anti-DMPK antibodies for immunoblotting. We estimated the amount of the full-length DMPK (85 kDa) in muscle biopsies from normal controls and from DM1 patients carrying different (CTG)_n expansions. We found that DMPK concentration was decreased to about 50% in DM patients’ muscles; the protein decrease did not seem correlated with the CTG repeat length. However, the fibre type composition in skeletal muscle seemed somehow to affect DMPK decrease, as the lowest level of the enzyme was found in patients with the lowest content of type 1 fibre.     

SB203580对肾缺血/再灌注损伤时细胞凋亡及p38MAPK影响的实验研究

目的　探讨不同时间及不同浓度p38MAPK特异性抑制剂SB2 0 35 80对肾缺血 /再灌注损伤过程中肾功能、细胞凋亡及 p38MAPK活性、表达量、p38MAPK底物的影响。 方法　 4 9只大鼠按缺血 /再灌注及给药时间的不同 ,随机分为 7组 ,每组7只大鼠按正交拉丁方表的顺序 ,经尾静脉注射相同体积、不同剂量的SB ,使其在大鼠体内达到不同的浓度。测定BUN和Scr;用TUNEL试剂盒检测细胞凋亡情况 ;Westernblot技术用于蛋白定性及半定量分析。结果　SB可显著减轻大鼠肾缺血 /再灌注损伤造成的Scr和BUN的升高、肾小管上皮细胞的凋亡及 p38MAPK的激活 ,但存在模型、剂量及给药时机的差异 (P<0 .0 5 ) ,缺血前 3h之前给药 ,使其体内血药浓度达到 5 μmol/L左右可取得较好的效果。 结论　SB可显著减轻大鼠肾缺血 /再灌注损伤 ,在缺血前 3h之前给药 ,同时使其血药浓度达到 5 μmol/L左右可取得最佳效果。     

Protein kinase C in focal ischemic rat brain: dual autoradiographic analysis of [C]iodoantipyrine (IAP) and [H]phorbol-12,13-dibutyrate (PDBu)

Protein kinase C (PKC) activity was measured in rat brain with 2 h of middle cerebral artery (MCA) and common carotid artery (CCA) occlusion, using dual autoradiography of [¹⁴C]iodoantipyrine (IAP) and [³H]phorbol-12,13-dibutyrate (PDBu). In the ischemic brain, it required more than 120 min of incubation to obtain a plateau in PDBu binding. In contrast, the binding of PDBu in non-ischemic brain reached a plateau with incubation for 60 min. This delay of PDBu binding in the ischemic brain suggests that the affinity of this ligand is reduced due to a change in structure of the cell membrane caused by ischemia. PDBu binding in the ischemic brain increased significantly compared to the non-ischemic brain. This finding provides further evidence that excessive activation of PKC in the ischemic brain may play an important role in ischemic neuronal damage. ©1997 Elsevier Science B.V. All rights reserved.