1,721,018 research outputs found
Interplay of peripheral neuropathy and hypertension in Type- 2 diabetes of short duration
No full textOur understanding of the IGF-I system has increased dramatically in recent yr due in part to the advances in molecular and cellular biology. Not only can we now measure circulating levels of the members of this axis in order to address the possibly pathophysiological changes, but genetic alterations can now be identified as the underlying cause of specific clinical situations. In normal children, circulating levels of IGF-I and the IGF binding proteins (IGFBPs) change throughout development and in some cases are gender dependent. Children and adolescents with a variety of illnesses and metabolic disorders have altered circulating IGF-I and IGFBP levels. Hence, in children or adolescents with exogenous obesity, anorexia nervosa, coeliac disease, leukaemia and other types of cancer, as well as in cases of GH deficiency, this axis can be altered. These data may help us to understand the physiology and pathophysiology of this system, but the clinical or diagnostic utility of these measurements is still largely debated. Indeed, in most of the above mentioned illnesses, circulating IGF and IGFBP levels overlap with normal values. Furthermore, these measurements do not provide data concerning levels of these factors at target tissues or of local synthesis and autocrine-paracrine effects. However, measurements of IGF-I and its binding proteins, as well as GH and its binding proteins, can help us to focus our analysis of patients suspected to have genetic abnormalities on the GH receptor, IGF-I, its receptor, IGFALS, or intracellular signalling proteins such as STAT5b or ERK. Possibly, the most clear clinical utility of circulating IGF-I measurements in children is in cases of GH deficiency or insensitivity or under GH treatment. However, the fact there are cases of children with non-detectable levels of circulating IGF-I that yet normal height and growth velocity, or with non-detectable levels of GH yet normal growth and IGF-I levels, raises many questions. Furthermore, circulating IGF-I levels may be within the normal control levels and the child may have a pathological growth pattern. Hence, just how useful are these measurements? Another clinically important question pertains to GH treatment in patients, such as in the Turner Syndrome, where supraphysiological levels of serum IGF-I are reached in order to induce growth. The interpretation and clinical utility of measurements of circulating IGF-I and its BPs are currently being widely discussed. As our knowledge of this system increases, with the identification of new members of this family and its intracellular mechanisms of action, as well as new genetic alterations in patients, the interpretation of laboratory results will also improve and help to better our diagnostic capability
Hypertension and Sensorimotor Peripheral Neuropathy in Type 2 Diabetes
No full textBackground: The mechanisms responsible for the onset of sensorimotor peripheral diabetic neuropathy (SMPN) remain largely unknown. To address this issue, we studied the relationship between traditional cardiovascular risk factors, parameters of metabolic control, and the presence of SMPN in patients with type 2 diabetes of relatively short duration. Methods: Blood pressure, glycated hemoglobin, lipid profile, and the presence of micro- and macrovascular complications were assessed and monitored in 31 consecutive ambulatory patients with type 2 diabetes (age 60.7 ± 7.5 years, mean ± SD) within 10 years of diagnosis (mean diabetes duration 6.0 ± 2.3 years). Results: Clinical and neurophysiological features of SMPN were present in 10 patients (SMPN+, 32%). There were no significant differences in age, gender distribution, diabetes duration, body mass index, metabolic control, and serum cholesterol between SMPN- and SMPN+ patients. However, the prevalence of hypertension (i.e. blood pressure ≥140/90 mm Hg) was higher in SMPN+ patients (10/10 vs. 13/21, χ2 = 5.13, p = 0.025). Regression analysis showed that, after correcting for age, gender, duration of diabetes, glycated hemoglobin, and cholesterol, the presence of hypertension was independently associated with SMPN (R2 = 0.17, p = 0.023). Conclusions: There is a strong association between hypertension and SMPN in type 2 diabetic patients with relatively short duration of disease. This relationship is independent of other risk factors. Copyrigh
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
THE IN-VITRO PRODUCTION OF THROMBOXANE-B(2) BY PLATELETS OF DIABETIC-PATIENTS IS NORMAL AT PHYSIOLOGICAL CONCENTRATIONS OF IONIZED CALCIUM
No full textPlatelets of patients with diabetes and no evidence of macroangiopathy produce normal amounts of thromboxane (Tx) B2 in vivo, whereas they usually show increased production in vitro. Since in vitro studies have been usually performed in citrated PRP, we tested the hypothesis that the discrepancy between in vivo and in vitro studies is due to the low concentration of plasma ionized calcium ([Ca2+](o)) that is present in citrated PRP. In fact, low [Ca2+](o) artifactually potentiates the platelet TxB2 production in vitro. Forty patients with diabetes mellitus and 37 matched controls were studied. Blood was anticoagulated with citrate, the thrombin inhibitor D-phenylalanyl-1-prolyl-1-chloromethylketone (PPACK) or both anticoagulants. Platelet aggregation, release of 14C-serotonin and TxB2 production were induced in platelet rich plasma (PRP) by several agonists. The following results were obtained: i) Citrated PRP: Arachidonic acid induced aggregation (p < 0.01) and TxB2 production (p < 0.02) were significantly greater in patients than in controls. No statistically significant differences were found with other agonists. ii) PPACK PRP: No statistically significant difference was found between diabetic platelets and controls. iii) PPACK plus citrate PRP: The results were not different from those obtained with citrate alone. Therefore, our results show that diabetic platelets produce normal amounts of TxB2 in vitro when the [Ca2+](o) is physiological
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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