Expression and kinetic characteristics of muscle type acetylcholine receptors in Xenopus oocytes

ＥｘｐｒｅｓｓｉｏｎａｎｄｋｉｎｅｔｉｃｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｍｕｓｃｌｅｔｙｐｅａｃｅｔｙｌｃｈｏｌｉｎｅｒｅｃｅｐｔｏｒｓｉｎＸｅｎｏｐｕｓｏｏｃｙｔｅｓＣｈｅｎＨｏｕｃｈａｎｇ（陈厚昌），ＷｕＳｈｕｇｕａｎｇ（吴曙光）（Ｄｅｐａｒｔ...     

Involvement of glutamate receptors,lipases, and phospholipases in long-term potentiation and neurodegeneration

Glutamate is the primary excitatory amino acid in the mammalian central nervous system. Normal excitation of glutamate receptors initiates the stimulation of phospholipases and lipases with the generation of second messengers that are necessary for normal cell function. The overstimulation of glutamate receptors can initiate a cascade of biochemical events including stimulation of membrane phospholipid turnover, excessive calcium entry, abnormal phosphorylation, and proteolysis. These events may be responsible for neuronal injury and degeneration found in Alzheimer disease, ischemia, spinal cord trauma, epilepsy, and Huntington disease.     

Thrombosis triggered by severe arterial lesions is inhibited by oral administration of a glycoprotein IIb/IIIa antagonist

Platelet aggregation and thrombosis play an important role in the onset of acute coronary events. Regardless of the stimulus for activation, platelet thrombus formation is ultimately regulated through the IIb/IIIa receptor complex. The effects of oral administration of xemilofiban, a non-peptide mimetic of the RGDF sequence of the IIb/IIIa receptor complex, on thrombus formation were evaluated in a canine model. Xemilofiban significantly reduced platelet deposition on severely damaged arterial wall. Platelet deposition was reduced at both low (13 ± 1 from 56 ± 18 × 10⁶ platelets cm⁻²; P  < 0.05) and high (23 ± 2 from 111 ± 21 × 10⁶ platelets cm⁻²; P  < 0.01) shear rates. Platelet deposition was reduced to a monolayer as seen by electron microscopy (platelet–vessel wall interaction). Therefore, the availability of an orally active IIb/IIIa antagonist for chronic use may have significant value in preventing thrombus formation in those clinical situations associated with severe arterial injury, such as atherosclerotic plaque disruption.     

重度妊娠高血压综合征患者胎盘表皮生长因子受体的表达

目的：研究胎盘表皮生长因子受体(EGFR)蛋白及基因的表达在置度妊娠高血压综合征(妊高征)发病中的作用以及对妊高征胎儿生长发育的影响。方法：采用免疫组织化学法和逆转录-聚合酶链反应(RT-PCR)技术测定21例重度妊高征患者[分2组，重度妊高征合并胎儿宫内发育迟缓(IUGR)组9例和重度妊高征未合并IUGR组12例]胎盘EGFR的表达，并与15例正常妊娠者(对照组)比较。结果：与对照组相比，重度妊高征患者胎盘EGFR蛋白及其mRNA的表达显著降低(P＜0．01)，重度妊高征合并EGFR组与重度妊高征未合并IUGR组之间胎盘EGFR的表达差异无显著性(P＞0．05)。结论：胎盘滋养层细胞EGFR表达显著降低，可能是重度妊高征发病的重要因素；如果EGFR的低表达发生较早，容易发生IUGR。     

Acetylcholine receptor antibody in myasthenia gravis

Radioimmunoassay techniques were used to detect antibodies to the acetylcholine receptor (AAChR) in 164 patients with adult-onset myasthenia gravis. AAChR levels above 0.6 nM/l were considered pathological and were found in 67% of the patients with an average value of 58.99 +/- 125.02 nM/l (0.6-900.0). Correlation, with clinical functional status, the histopathological thymus alterations and the different therapeutics used did not disclose any statistically significant differences.     

重症肌无力患者泼尼松治疗前后免疫学指标的变化

探讨泼尼松治疗重症肌无力（MG）免疫学机制。对382例MG患者在漏尼松中剂量冲击，小剂量维持疗法治疗前后，检测酰胆碱受体抗炎（AchRab)，突触前膜抗体（PsMab)，单个核细胞亚群（PBMC），肿瘤坏死因子（TNF），可溶性白介素－2受体（SIL－2R），β2－微球蛋白（β2－m)，以及红细胞免疫功能的变化。结果表明：MG患者在泼尼松治疗前后多项免疫指标有显著性的变化。为泼尼松治疗MG提供了评定疗效的免疫学指标，进一步阐明了MG发病的免疫学机制。     

Studies on SSTR2 mRNA expression and its correlation to steroid receptors in human benign and malignant breast lesions

Objective:This sudy was designed to observe somatostatin receptor subtype 2 (SSTR2) Mrna expression, and investigate the correlations between SSTR2 Mrna expression and steroid receptors in benign and malignant lesions of the breast. Methods: A total of 23 breast carcinomas,16 mammary hyperplasia and 9 mammary adenofibroma samples were analysed. The SSTR2 Mrna expression was examined by in situ hybridization using multiphase oligoprobes.The ER and PR were detected by immunohistochemical staining. A computerized image analysis system was utilized to estimate the relative contents of SSTR2 Mrna. Results: The positive rates of expression (87.0%) and relative contents (0.47) of SSTR2 Mrna in breast cancer were higher than those in benign breast lesions(64%,0.26) respectively( P＜0.05). SSTR2 Mrna expression was closely correlated with ER and PR in breast cancer( P＜0. 05), A positive correlation between SSTR2 Mrna expression and ER was also found in benign breast lesions. Conclusions: SSTR2 Mrna expressed both in benign and in malignant breast lesions, but higher in malignant than in benign ones. There was a significant positive correlation of SSTR2 Mrna expression with ER or PR. The results suggest that conbined treatment with an antiestrogen and a somatostatin analogue for ER-positive breast cancer is feasible.     

胆汁胆固醇对胆囊收缩素受体表达的影响

目的：探讨胆汁胆固醇对胆囊收缩素受体（CCK－R）表达的影响。方法 采用放射免疫分析法和受体放射配基结合法检测对照组、高胆固醇组、自然恢复组及治疗组豚鼠门静脉血CCK水平、胆囊CCK－R的最大结合容量（Bmax）和亲和力（Kd），同时观察空腹胆囊体积（FV）、胆囊胆汁量（FB）和餐后胆囊体积（RV）、胆囊胆汁量（RB）及胆囊收缩率（E％）、胆汁胆固醇浓度的变化。结果 与对照组比较，高胆固醇组豚鼠FV、FB增大（P＜0.05），RV、RB也增大，胆囊收缩率下降（P＜0.01），胆汁胆固醇浓度升高（P＜0.05），门静脉血CCK水平及CCK－R的Kd无改变，而CCK－R的Bmax下降（P＜0.01）；治疗组上述各项指标正常。结论 胆汁中的高胆固醇通过下调胆囊CCK－R表达而导致胆囊收缩功能障碍，降低胆汁高胆固醇浓度可以促进胆囊动力功能的恢复。     

Synthesis and biological activity of Substance P C-terminal hexapeptide and heptapeptide analogues

The analogues [Glu(OBzl)¹¹]SP_6–11 and [Glu(OBzl)¹¹]SP_5–11 of the C-terminal hexapeptide and heptapeptide of Substance P have been synthesized by conventional solution methods. In each analogue the SCH₃ group of Met¹¹ is replaced by the COOCH₂C₆H₅ group. The in vitro activity of both analogues has been determined on three biological preparations: guinea pig ileum (GPI), rat vas deferens (RVD), and rat portal vein (RPV). The selectivity for the different receptors has been studied by utilizing atropine-treated guinea pig ileum (GPI + At). The results showed that both analogues are mainly active on GPI through the NK-1 receptor and that both analogues are equipotent to Substance P.