重症肌无力病人乙酰胆碱受体抗体的测定及临床意义

用ＥＬＩＳＡ（固相酶联免疫吸附）法测定１７２例ＭＧ病人血清乙酰胆碱受体抗体（ＡｃｈＲａｂ），结果显著高于健康献血员组和非ＭＧ病人组。不同性别、病程及临床类型与ＡｃｈＲａｂ无相关性，但４１～５０岁组的显著高于其他年龄组。６７例类固醇激素治疗组、２２例大剂量两种球蛋白治疗组、１２例胸腺切除术组及３例ＭＧ危象病人２４次血浆交换疗法（ＰＥ）组，治疗后伴随肌无力症状的好转，ＡｃｈＲａｂ均显著低于治疗前。结果表明：ＡｃｈＲａｂ测定为ＭＧ诊断提供了可靠的实验依据，为类固醇激素、大剂量丙种球蛋白、胸腺切除术和ＰＥ等治疗ＭＧ提供理论依据和疗效评定的实验指标，进一步证实了ＭＧ免疫学发病机理。     

Mechanisms underlying the antidopaminergic effect of clonazepam and melatonin in striatum

Intrastriatal injection of the GABA_A antagonist, bicuculline, caused about a 75% decrease in the inhibitory effect of the central-type benzodiazepine (BZ) agonist, clonazepam or the indoleamine hormone, melatonin, on apomorphine-induced rotation in a 6-hydroxydopamine model of dopaminergic supersensitivity. Pretreatment with the peripheral-type BZ antagonist, PK 11195 (intrastriatally or intraperitoneally), also attenuated the antidopaminergic effect of these drugs but with much less potency than bicuculline. However, the combination of both bicuculline and PK 11195, injected directly into the striatum, completely blocked the antidopaminergic action of clonazepam or melatonin. These results indicate that the antidopaminergic action of clonazepam and melatonin in the striatum involves two distinct mechanisms: (1) a predominant GABAergic activation via the BZ/GABA_A receptor complex, and (2) a secondary mechanism linked to a PK 11195- sensitive BZ receptor pathway. Recent studies indicate that PK 11195 blocks BZ-induced inhibition of the adenylyl cyclase-cyclic AMP pathway in the striatum. Since cyclic AMP has been implicated in the rotational behaviour of 6-hydroxydopamine-lesioned animals, it is possible that the antidopaminergic action of clonazepam and melatonin also involves suppression of this second messenger. All rights reserved.     

凝集素受体在膀胱癌中的分布

目的：探讨膀胱癌中凝集素受体分布与其分化程度和浸润深度的关系。方法：应用生物素标记的花生凝集素（ＰＮＡ）、麦胚凝集素（ＷＧＡ）及刀豆凝集素（ＣｏｎＡ）等３种凝集素对５２例人体膀胱癌、１０例正常人体膀胱粘膜，进行亲合组织化学法研究。结果：发现正常膀胱粘膜ＰＮＡ、ＷＧＡ受体阴性，ＰＮＡ受体阳性率随膀胱癌病理分级的上升而递增，差异具有显著性意义（Ｐ＜０．０５）。ＰＮＡ、ＷＧＡ受体阳性率在浸润性肿瘤中明显高于浅表性肿瘤（Ｐ＜０．０５）。结论：提示ＰＮＡ、ＷＧＡ受体阳性率与膀胱癌分化程度和浸润深度有关。     

The desipramine-induced growth hormone response and the dexamethasone suppression test in obsessive-compulsive disorder.

Ten patients with DSM-III-R obsessive-compulsive disorder (OCD) underwent the desipramine (DMI) growth hormone (GH) stimulation test as well as the dexamethasone suppression test (DST). The results were compared with the responses in a group of matched healthy controls. The GH response to DMI did not differ between patients and controls and 9 of 10 patients showed cortisol suppression in response to dexamethasone. The data suggest that neither alpha 2 adrenergic dysfunction nor DST non-suppression are features of primary OCD.     

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。     

Variation analysis of β3-adrenergic receptor and melanocortin-4 receptor genes in childhood obesity

BACKGROUND: Decreased energy expenditure and increased food intake are principal causes for obesity. In the present study, genotypes of beta(3)-adrenergic receptor (beta(3)AR) and of melanocortin-4 receptor (MC4R), both of which are believed to have a close link to the cause of obesity, were analyzed and compared with phenotypes of childhood obesity. METHODS: Thirty-five obese children with moderate to severe obesity were enrolled. Direct sequencing of the MC4R coding region and pinpoint-polymerase chain reaction were used to detect genomic variation in the beta(3)AR gene using peripheral blood-derived DNA. RESULTS: Allele frequency of Trp64Arg variation in the beta(3)AR gene in the obese subjects was 0.16, which is comparable with that in the healthy general population in eastern Asia. Comparison of phenotypical characteristics did not show a significant difference between Trp/Trp and Trp/Arg subjects. It was notable that body height SD was significantly higher in the Trp/Trp than the Trp/Arg subjects (0.93 +/- 1.0 SD vs 0.07 +/- 1.3 SD, P= 0.03). Annual weight gains were far beyond a hypothetical fat gain in an Arg64 heterozygote with decreased energy consumption, suggesting increased food intake in childhood obesity. There was, however, no variation in the MC4R gene despite thorough sequencing of the entire coding region. CONCLUSIONS: The Trp64Arg variation in the beta(3)AR gene has no relationship to the degree or the incidence of childhood obesity. The majority of childhood obesity can be characterized as tall stature, more rapid weight gain than that expected by decreased energy expenditure. Further investigation is necessary in regard to the increased food intake as a major cause of childhood obesity.     

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.