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31.
On the action of strophanthin G   总被引:2,自引:0,他引:2  
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32.
Recent research suggesting that nicotine cues are appetitive in nature promotes the affective modulation of the startle reflex (AMSR) paradigm as a potentially valuable psychophysiological tool for elucidating mechanisms involved in nicotine addiction. Despite numerous studies indicating stress as a key factor in nicotine dependence, specific behavioral mechanisms linking stress and smoking have yet to be explicated. The current study aimed to determine the effects of stress, a negative affective state intimately linked with nicotine use, on the psychophysiological responding of nicotine dependent individuals during smoking cues. Twenty-nine nicotine dependent individuals were randomly assigned to the trier social stress test or control condition directly prior to administration of the AMSR paradigm, which examined their physiological responses to appetitive, neutral, aversive, and nicotine cue images. Both groups evinced significantly decreased startle magnitudes in response to nicotine cues as compared to aversive images. However, exposure to stress did not significantly modulate the startle reflex while viewing nicotine cues. Stress induction does not appear to modulate the AMSR paradigm when evaluating responses to nicotine images. These findings suggest that AMSR is robust to effects of acute stress induction in nicotine dependent individuals which may increase its viability as a clinical tool for assessing success in smoking cessation interventions.  相似文献   
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In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity.  相似文献   
35.
The autoantigenic polymyositis/scleroderma (PM/Scl) complex was recently shown to be the human homologue of the yeast exosome, which is an RNA-processing complex. Our aim was to assess whether, in addition to targeting the known autoantigens PM/Scl-100 and PM/Scl-75, autoantibodies also target recently identified components of the PM/Scl complex. The prevalence of autoantibodies directed to six novel human exosome components (hRrp4p, hRrp40p, hRrp41p, hRrp42p, hRrp46p, hCsl4p) was determined in sera from patients with idiopathic inflammatory myopathy (n = 48), scleroderma (n = 11), or the PM/Scl overlap syndrome (n = 10). The sera were analyzed by enzyme-linked immunosorbent assays and western blotting using the affinity-purified recombinant proteins. Our results show that each human exosome component is recognized by autoantibodies. The hRrp4p and hRrp42p components were most frequently targeted. The presence of autoantibodies directed to the novel components of the human exosome was correlated with the presence of the anti-PM/Scl-100 autoantibody in the sera of patients with idiopathic inflammatory myopathy (IIM), as was previously found for the anti-PM/Scl-75 autoantibody. Other clear associations between autoantibody activities were not found. These results further support the conception that the autoimmune response may initially be directed to PM/Scl-100, whereas intermolecular epitope spreading may have caused the autoantibody response directed to the associated components.  相似文献   
36.
We describe here a simple, general procedure for the purification of a variety of lectins, and for the preparation of lectin-ferritin conjugates of defined molar composition and binding properties to be used as probes for cell surface saccharides. The technique uses a “universal” affinity column for lectins and their conjugates, which consists of hog sulfated gastric mucin glycopeptides covalently coupled to agarose. The procedure involes: (a) purification of lectins by chromatography of aqueous extracts of seeds or other lectin-containing fluids over the affinity column, followed by desorption of the desired lectin with its hapten suge; (b) iodination of the lectin to serve as a marker during subsequent steps; (c) conjugation of lectin to ferritin with glutaraldehyde; (d) collection of active lectin-ferritin conjugates by affinity chromatography; and (e) separation of monomeric lectin-ferritin conjugates from larger aggregates and unconjugated lectin by gel chromatography. Based on radioactivity and absorbancy at 310 nm for lectin and ferritin, respectively, the conjugates consist of one to two molecules of lectin per ferrritin molecule. Binding studies of native lectins and their ferritin conjugates to dispersed pancreatic acinar cells showed that the conjugation procedure does not significantly alter either the affinity constant of the lectin for its receptor on the cell surface or the number of sites detected.  相似文献   
37.
Ultrastructural studies on mitochondrial swelling   总被引:1,自引:0,他引:1       下载免费PDF全文
Mitochondrial swelling induced by valinomycin, calcium chloride and P(i) was studied after potassium permanganate fixation in suspension. Valinomycin induces a rapid K(+) influx, increase of the matrix space and out-folding of the cristae, with good preservation of the matrix material. This swelling is reversible but the cristae do not completely re-form and have a blebbed appearance. On repeated swelling and contraction cycles there is a gradual loss of matrix material. Calcium chloride and P(i) produce a slow swelling of the matrix space. Shrinkage induced by ATP was partial and not associated with return to the original structure.  相似文献   
38.
High-throughput approaches are beginning to have an impact on many areas of yeast biology. Two recent studies, using different experimental platforms, provide insight into new pathways involved in the response of yeast to DNA damage.  相似文献   
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40.

Background

The objective of this study was to evaluate angiogenesis according to CD34 antigen expression in estrogen receptor (ER)-positive and negative breast carcinomas.

Methods

This study comprised 64 cases of infiltrating ductal carcinoma in postmenopausal women divided into two groups: Group A: ER-positive, n = 35; and Group B: ER-negative, n = 29. The anti-CD34 monoclonal antibody was used as a marker for endothelial cells. Microvessel count was carried out in 10 fields per slide using a 40× objective lens (magnification 400×). Statistical analysis of the data was performed using Student's t-test (p < 0.05).

Results

The mean number of vessels stained with the anti-CD34 antibody in the estrogen receptor-positive and negative tumors was 23.51 ± 1.15 and 40.24 ± 0.42, respectively. The number of microvessels was significantly greater in the estrogen receptor-negative tumors (p < 0.001).

Conclusion

ER-negative tumors have significantly greater CD34 antigen expression compared to ER-positive tumors.
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