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。     

Quantitative autoradiographic study of L-glutamate binding sites in normal and atrophic human cerebellum.

In the present work the distribution of L-glutamate binding sites in the different layers of human cerebellum of normal individuals and of seven patients who died with olivopontocerebellar atrophy (OPCA) was examined with the technique of quantitative autoradiography. Specific L-[3H]glutamate binding was higher in the molecular than in the granule cell layer of normal cerebellar tissue. A significant decrease of L-[3H]glutamate specific binding was observed in the molecular layer of all OPCA tissues. In the granule cell layer L-[3H]glutamate binding was decreased only in two patients who suffered from late-onset sporadic OPCA and in one patient who suffered from a form of OPCA inherited in a dominant manner. Quisqualate-sensitive binding sites were the most abundant binding sites in the molecular layer of normal cerebella, whereas N-methyl-D-aspartic acid (NMDA)-sensitive binding sites were the most abundant type in the granule cell layer. A significant decrease of quisqualate-sensitive and an increase in NMDA-sensitive binding sites were observed in the molecular layer of OPCA cerebellar tissues. No significant changes were observed in the granule cell layer of these tissues.     

Effect of CNTF on low-affinity NGF receptor expression by cultured neurons from different rat brain regions.

Our previous work indicated that in E14 embryonic rat spinal cord cultures ciliary neuronotrophic factor (CNTF) exerted (1) a survival-promoting effect on motor neurons and on a large population of unidentified neurons, and (2) a regulatory role on the expression of ChAT and low affinity NGF receptor (LNGFR) in a population of small/medium-sized neurons. In the present study, we examined the effect of CNTF on the expression of LNGFR in cultures of different regions from the E18 embryonic rat brain, namely cortex, septum, striatum, mesencephalon, hippocampus, brainstem, and cerebellum. The number of LNGFR-positive neurons (stained with the 192-IgG monoclonal antibody) was determined in untreated cultures and in cultures treated for 6 days (0-6) with human recombinant CNTF. To distinguish between effects on survival and on LNGFR expression, experiments were performed in which CNTF was administered only for the last 48 h of the culture (from days 4-6). LNGFR positive neurons were found in the cultures of all the regions examined. In each one of them, CNTF increased the number of LNGFR-positive neurons by three- to fourfold after 6 days of treatment. In the striatum, septum, mesencephalon, and cerebellum, the effect of CNTF was shown to be on the regulation of LNGFR expression and not on survival. In cultures from the cortex, hippocampus and brainstem, a survival-promoting role of CNTF could be demonstrated. The effect of CNTF was dose dependent, with half-maximal effects (ED50) achieved at 2-4.5 TU/ml for all the brain regions. Maximal effects were reached at 100-250 TU/ml. From these results, we conclude that (1) there exists a wide spectrum of CNTF-responsive neurons in the central nervous system, and (2) CNTF plays an important and widespread role in regulating the expression of the LNGFR in neurons.     

Regulation of neurotransmitter enzyme by quisqualate subtype glutamate receptors in cultured cerebellar and hippocampal neurons

The possible involvement of ionotropic and metabotropic quisqualate (QA) receptors in neuronal plasticity was studied in cultured glutamtergic cerebellar or hippocampal cells in terms of the specific activity of phosphate-activated glutaminase, an enzyme important in the synthesis of the putative neurotransmitter pool of glutamate. When cerebellar of hippocampal neurons were treated with QA, it elevated the specific activity of glutaminase in a dose-dependent manner. The half-maximal effect was obtained at about 0.1 μM, the maximum increase was at about 1 μM, but levels higher than 10 μM QA produced progressive reduction in glutaminase activity. In contrast, QA had little effects on the activities of lactate dehydrogenase and aspartate aminotransferase and the amount of protein, indicating that the increase in glutaminase was relatively specific. The QA-mediated increase in glutaminase was mimicked by the ionotropic QA receptor agonist -amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA; EC₅₀, about 0.5 μM), but not by the metabotropic QA receptor agonist trans-(±)-1-aino-cyclopentyl-1,3,dicarboxyalte (t-ACPD; up to 0.5 mM). The specific ionotropic QA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) inhibited QA- and AMPA-mediated increases in glutaminase activity in a dose-dependent manner, whereas other glutamate receptor antagonists, -2-amino-5-phosphonovalerate, γ- -glutamyl aminomethyl sulphonic acid and γ- -glutamyl diethyl ester were ineffective. The elevation of neurotransmitter enzyme was Ca²⁺-dependent. The increase in Ca²⁺ influx essentially through the activation of L-type voltage-operated Ca²⁺ channels, and not the mobilization of internal Ca²⁺ stores, was responsible for these QA receptor-mediated long-term plastic changes in hippocampal and cerebellar neurons.     

Expression of cell-matrix molecules and integrin receptors in human liver grafts during chronic rejection

Abstract The inflammatory response of immune cells to target cells and cell-matrix molecules is regulated by several receptor-ligand molecules. As fibrosis develops in ongoing chronic rejection after liver transplantation, it is of interest to analyze patterns of integrin receptors and cell-matrix molecules in order to study the relation between immune cells and the stromal and parenchymal cells. In the present study, we demonstrated the expression of these molecules in chronic rejected human liver grafts using immunohistochemical techniques. The results showed a differential expression and induction of integrin receptors and cell-matrix molecules on resident liver cells, especially on sinusoids, reflecting a state of chronic inflammation and a specific interaction between integrin receptors and cell-matrix molecules. The patterns of induced integrin receptors on graft-infiltrating cells was closely related to the local production of cell-matrix molecules and reflected the final sequence of a stepwise progress of the inflammatory reaction.     

Soluble Fcγ receptors in periodontal lesions

Soluble Fcγ-binding components were detected in gingival fluid from periodontal lesions by incubation with biotinylated human Fcγ fragments. FcγIII receptor was identified by incubation of gingival fluid with monoclonal antibody. Sodium dodecyl sulfate-polyacrylamide gel electophoresis and Western transfer showed that most of the Fcγ-binding components had minimal mobility in a 4–15% gradient gel under nonreducing conditions. Under reducing conditions, the main band of Fcγ-binding components in gingival fluid migrated corresponding to protein A of 49 kDa. The pattern of Fcγ-binding components was similar in serum and gingival fluid except for the observation in gingival fluid of Fcγ-binding components migrating like standard proteins of 19 to 20 kDa, a size that corresponds to the polypeptide part of FcγII receptor and FcγIII receptor.     

In vitro contracture test for diagnosis of malignant hyperthermia following the protocol of the European MH Group: Results of testing patients surviving fulminant MH and unrelated low-risk subjects

Background: Determination of sensitivity and specificity of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility using the European MH Group (EMHG) protocol has been performed in some laboratories but only on a small sample from the combined EMHG. Thus, the purpose of the present study was to determine combined EMHG sensitivity and specificity of the test. Methods: Results of IVCT of patients with previous fulminant MH and normal, low-risk subjects (controls) were collected from 22 centresof the EMHG. IVCT was performed according to the EMHG protocol. Patients were included inthe study if the clinical crisis had a score of at least 50 points with the Clinical Grading Scale. Low-risk subjects were included provided they did not belong to a family with known MH susceptibility, they had not developed any signs of MH at previous anaesthetics, and they did not suffer from any neuromuscular disease. For inclusion of both MH patientsand low-risk subjects, at least 1 muscle bundle in the IVCT should have twitches of 10 mN(1 g) or more. For evaluation of individual tests, only muscle bundles with twitch heights of 10 mN (1 g) or more were used. Results: A total of 1502 probands had undergone IVCT because of a previous anaesthesia with symptoms and signs suggestive of MH. Of these, 119 had clinical scores of 50 and above. From these 119 MH-suspected patients and from 202 low-risk subjects, IVCT data were collected. Subsequently, 14 MH-suspected patients were excluded from further analysis for thefollowing reasons: In 3 patients, the suspected MH episode could be fully explained by diseases other than MH; in 11 MHS patients, IVCT was incomplete (n=l), data were lost (n=3), or none of the muscle bundles fulfilled twitch criteria (n=7). Of the remaining 105 MH-suspected patients, 89 were MHS, 10 MHEh, 5 MHEc, and one MHN. Thus, we observed a diagnostic sensitivity of the IVCT of 99.0% if the MHE group is considered susceptible(95% confidence interval 94.8–100.0%). Of the 202 low-risk subjects, 3 were MHS, 5 MHEh, 5 MHEc, and 189 MHN. This gives a specificity of the IVCT of 93.6% (95% confidence interval 89.2–96.5%). Conclusion: The IVCT for diagnosis of MH susceptibility in Europe has a high sensitivity and a satisfactory specificity.     

Estrogenic Induction of NADPH- Diaphorase Activity in the Preoptic Neurons Containing Estrogen Receptor Immunoreactivity in the Female Rat

Nitric oxide and estrogen have been shown to play a critical role in the control of female reproductive function. In order to determine an anatomical relationship between nitric oxide generating neurons and estrogen target neurons, NADPH-diaphorase histochemistry was combined with estrogen receptor immunohistochemistry in the female medial preoptic area. While only a few weakly stained neurons for NADPH-diaphorase were found in ovariectomized control rats, a drastic increase in NADPH-diaphorase activity was observed in the medial preoptic nucleus of estradiol-treated ovariectomized animals. The total number of NADPH-diaphorase neurons in the estradiol-treated group increased three-fold relative to controls, and more than 80% of those neurons contained estrogen receptor-immunoreactivity in their nuclei. Since neuronal NADPH-diaphorase is nitric oxide synthase, the present result suggests that nitric oxide synthase activity can be positively regulated by estradiol in neurons containing estrogen receptor in the female medial preoptic nucleus.