1,721,211 research outputs found
Glucose production during an IVGTT by deconvolution : validation with the tracer-to-tracee clamp technique
Full text linkRecently, a new method, based on a two-compartment minimal model and deconvolution [A. Caumo and C. Cobelli. Am. J. Physiol 264 (Endocrinol. Metab. 37): E829-E841, 1993; P. Vicini, G. Sparacino, A. Caumo, and C. Cobelli. Comput. Meth. Prog. Biomed. 52: 147-156, 1997], has been proposed to estimate endogenous glucose production (EGP) from labeled intravenous glucose tolerance test (IVGTT) data. Our aim here is to compare this EGP profile with that independently obtained with the reference method, based on the tracer-to-tracee ratio (TTR) clamp. An insulin-modified (0.03 U/kg body wt infused over 5 min) [6,6-2H2]glucose-labeled IVGTT (0.33 g/kg of glucose) was performed in 10 normal subjects. A second tracer ([U-13C]glucose) was also infused during the test in a variable fashion to clamp endogenous glucose TTR. The TTR clamp was quite successful. As a result, the EGP profile, reconstructed from [U-13C]glucose data with the models of Steele and Radziuk, were almost superimposable. The deconvolution-obtained EGP profile, calculated from [6,6-2H2]glucose data, showed remarkable agreement with that obtained from the TTR clamp. Some differences between the two profiles were noted in the estimated basal EGP and in the initial modalities of EGP inhibition. A high interindividual variability was also observed with both methods in the resumption of EGP to baseline; variability was high in both the timing and the extent of resumption. In conclusion, the use of the two-compartment minimal model of the IVGTT and deconvolution allows the estimation of a profile of EGP that is in very good agreement with that independently obtained with a TTR clamp
The hot IVGTT two-compartment minimal model : indexes of glucose effectiveness and insulin sensitivity
Full text linkA two-compartment minimal model (2CMM) has been proposed [A. Caumo and C. Cobelli. Am. J. Physiol. 264 (Endocrinol. Metab. 27): E829-E841, 1993] to describe intravenous glucose tolerance test (IVGTT) labeled (hereafter hot) glucose kinetics. This model, at variance with the one-compartment minimal model (1CMM), allows the estimation of a plausible profile of glucose production. The aim of this study is to show that the 2CMM also allows the assessment of insulin sensitivity (SI2*), glucose effectiveness (SG2*), and plasma clearance rate (PCR). The 2CMM was identified on stable-isotope IVGTTs performed in normal subjects (n = 14). Results were (means +/- SE) SG2* = 0.85 +/- 0.14 ml.kg-1.min-1, PCR = 2.02 +/- 0.14 ml.kg-1.min-1, and SI2* = 13.83 +/- 2.54 x 10(-2) ml.kg-1.min-1.microU-1.ml. The 1CMM was also identified; glucose effectiveness and insulin sensitivity indexes were SG*V = 1.36 +/- 0.08 ml.kg-1.min-1 and SI*V = 12.98 +/- 2.21 x 10(-2) ml.kg-1.min-1.microU-1.ml, respectively, where V is the 1CMM glucose distribution volume. SG*V was lower than PCR and higher than SG2* and did not correlate with either [r = 0.45 (NS) and r = 0.50 (NS), respectively], whereas SI*V was not different from and was correlated with SI2* (r = 0.95; P < 0.001). SG* compares well (r = 0.78; P < 0.001) with PCR normalized by the 2CMM total glucose distribution volume. In conclusion, the 2CMM is a powerful tool to assess glucose metabolism in vivo
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
Use of local hyperthermia as prophylaxis of fibrosis and modification in penile length following radical retropubic prostatectomy
No full textObjective: The aim of the study was to evaluate the effectiveness of local hyperthermia in reducing possible penile shortening following radical retropubic prostatectomy. Patients and methods: The study population comprised 40 patients, aged 52 - 74 years, submitted to radical retropubic prostatectomy. Patients were divided into two groups of 20. In Group A, patients were submitted to local hyperthermia 3 weeks after surgery, three times a week, with treatment lasting 30 min. Patients received a total of 10 applications, which reached a local temperature of 39 - 40 degrees C. A second cycle was repeated after 1 month. In Group B, patients were submitted only to post-operative follow-up once a month. Penile length was measured in all patients both before and 3 months after surgery in the 'stretching phase' from the pubo-penile junction to the tip of the glans. Results: In Group A patients ( hyperthermia treatment), no variation in penile length was observed in 16 cases (80%), while the reduction ranged from 0.5 - 1.5 cm in four cases (20%). In Group B, 12 patients (60%) showed a reduction in penile length ranging from 0.5 - 2.5 cm, while penile length remained unchanged in eight patients (40%). Conclusions: Results of this study demonstrate a mild but statistically relevant reduction in penile shortening following low-grade, externally delivered penile hyperthermia, thus confirming the efficacy of this approach in preventing penile shortening caused by post-ischaemic fibrosis
Profilassi della fibrosi e delle variazioni in lunghezza del pene mediante utilizzo della ipertermia nel paziente sottoposto a prostatectomia radicale
No full textVariations 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
Role of hyperthermia in the treatment of Peyronie's disease: A preliminary study
No full textObjective: Previous experience in the treatment of plaque with hyperthermia in orthopaedics led the authors to investigate the effectiveness of this approach in patients with Peyronie's disease. Patients and methods: The study population comprised 60 patients ( aged 36 - 76 years) with advanced Peyronie's disease. Patients were divided into two groups ( A and B), with 30 in each. Group A patients underwent local hyperthermia treatment, with 30-min treatment sessions twice a week for 5 weeks. Patients received a total of 10 applications, which reached a local temperature of 39 - 40 degrees C. A second cycle was repeated after a 1-month interval for a total of 20 treatment sessions. Group B patients were treated with intra-plaque infiltrations using 10 mg verapamil; they received one infiltration once a week for 3 months. Differences between the two groups, as well as between variables ( before and after treatment), were analysed using Student t-test and Fisher test. Results: Hyperthermia significantly reduced plaque size and penile curvature and led to an increase in mean scores of erectile function (EF) domain, while verapamil had no such effects. Haemodynamic parameters were not significantly modified in either group. Hyperthermia caused significantly fewer side effects than verapamil infiltrations and was significantly more effective in preventing disease progression. There were no significant differences between the two groups in terms of pain reduction during erection. Conclusions: Results of this study stress the efficacy of hyperthermia in the treatment of advanced Peyronie's disease
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
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