1,720,962 research outputs found
Systemic sclerosis and cancer
To review recent advances and current controversies on the association between systemic sclerosis (SSc) and cancer, PUBMED was searched from 1966 to the present using the terms: systemic sclerosis, cancer, morphoea, sclerotic diseases. Malignancies, mainly in lung and breast, coexist with idiopathic SSc or with SSc-like disorders, but not with localized forms of scleroderma (morphoea), with the exception of squamous cell carcinoma in patients with pansclerotic morphoea and skin ulcers. The mechanisms connecting SSc and malignancies are unknown. The occurrence of different cancer types with SSc or SSc-like disorders suggest different underlying mechanisms, including altered immune response, common genetic and environmental links, disease-dependent factors, tumor-derived biologic substances and therapies. The process of sclerosis itself may favour cancer in certain sites, and a reaction between T cells and neoantigens formed during irradiation has been suggested to explain the frequent development of morphoea after breast irradiation. Radiotherapy, especially when used for breast cancer, may trigger idiopathic SSc or morphoea and influence the severity of preexisting SSc, with the consequence that SSc is considered a relative contraindication to breast radiotherapy. In conclusion, cancer and SSc may be associated, but it is still controversial as to whether there is a causal relationship. Continuing interest in these associations, in particular in the different modalities of associations, may help to understand the underlying biological mechanisms and to identify patients at risk. Copyrigh
Leucotriene B4 and peptido-leucotriene levels during radiographic contrast media infusion
The pathogenic mechanisms of radiographic contrast media (CM) reactions are still not well understood. Recently it has been proposed that leukotrienes (LT) may be involved in CM reactions. We measured plasma LTB4 and peptido-LT levels in 20 subjects undergoing urography with 2 low osmolality CM (ioxaglate and iopamidol) in order to elucidate if CM infusion determines LT release in plasma. LTB4 and peptido-LT did not change significantly during infusion of the 2 CM. Blood pressure, heart rate, and the number of circulating granulocytes were not affected by CM infusions, further evidence that LT release did not occur. We conclude therefore that LT are not released during infusion with the CM studied
Complement system is not activated in primary biliary cirrhosis
There is controversial evidence suggesting that the classical pathway of complement system is chronically activated in primary biliary cirrhosis (PBC) and that complement activation may be important in development of bile duct injury. We have reevaluated this issue by measuring by-products of complement activation such as C4a, C3a, Bb, and terminal complement complexes (SC5b-9) in plasma of 44 PBC patients with sensitive methods not previously used to detect complement activation in this disease. Age-matched healthy women and patients with chronic hepatitis of different etiology were studied as controls. We found that PBC patients have normal C4a concentrations. This finding argues strongly against chronic classical pathway activation. Although a minor increase of C3a levels was observed in a minority of PBC patients, the C3a/C3 ratio, an index used to evaluate the extent of native protein conversion, was remarkably similar in all groups. Potentially lytic terminal complement complexes were not increased. PBC patients had normal Bb plasma levels, indicating that the alternative pathway is also not activated. C3 concentration was higher in PBC patients than in healthy subjects and in chronic hepatitis patients, particularly in the early stages of the disease. C3 and C4 concentrations became lower in PBC and chronic hepatitis with the progression of the disease. The increase of C3 concentration in PBC does not reflect liver inflammation, since serum levels of C-reactive protein are normal. We found high serum C3 levels in patients with rare chronic cholestatic syndromes without superimposed infections and observed that serum C3 levels paralleled those of bilirubin in a patient with benign recurrent intrahepatic cholestasis. In conclusion, our data indicate that complement is not activated in PBC and that the increase of serum C3 levels is related to cholestasis
Thrombolytic treatment and complement activation
Details of possible complement activation in acute myocardial infarction (AMI) and the in vivo effects of fibrinolytic agents on this activation are not yet known. We measured complement activation in 40 patients with AMI: 20 were treated with streptokinase, and 20 did not receive any fibrinolytic agent. Anaphylatoxin C4a, C3a and membrane attack complexes SC5b-9 increased about 10-fold (p < 0.0001) during streptokinase infusion. There were no increases in complement catabolic products in AMI patients not treated with streptokinase. Significant transient leukopenia (-29.5%, 7.0 SEM, p = 0.001) and a drop in systolic pressure (-29%, 3.4 SEM, p < 0.0001) occurred after 15 min of streptokinase infusion simultaneously with the peak of anaphylatoxins in plasm
Esophageal scintigraphy with a semisolid meal to evaluate esophageal dysmotility in systemic sclerosis and Raynaud's phenomenon
Esophageal transit scintigraphy seems to be a valid methodology to assess impaired esophageal motility in early stages of disease. The purpose of this study was to discriminate patients with primary Raynaud's phenomenon (RP) and patients with systemic sclerosis (SSc) from healthy subjects by esophageal scintigraphy with a semisolid meal
A case of atypical giant cell arteritis diagnosed by positron emission tomography (PET)
The authors describe an atypical case of a patient having giant cell arteritis presenting only with fever, diagnosed by positron emission tomography and subsequently confirmed by temporal artery biopsy
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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