1,720,969 research outputs found
The Cholinergic and ACE-2-Dependent Anti-Inflammatory Systems in the Lung: New Scenarios Emerging From COVID-19
Full text linkThe renin angiotensin system and the cholinergic anti-inflammatory pathway have been recently shown to modulate lung inflammation in patients with COVID-19. We will show how studies performed on this disease are starting to provide evidence that these two anti-inflammatory systems may functionally interact with each other, a mechanism that could have a more general physiological relevance than only COVID-19 infection
Effects of oleuropein and pinoresinol on microvascular damage induced by hypoperfusion and reperfusion in rat pial circulation
No full textObjective: The present study was aimed to assess the in vivo acute effects of oleuropein or/and pinoresinol, polyphenols widely diffused in natural sources, on rat pial microvascular responses during transient BCCAO and reperfusion.
Methods: Rat pial microcirculation was visualized by fluorescence microscopy through a closed cranial window. Pial arterioles were classified into five orders of branching. Capillaries were assigned order 0, the smallest arterioles order 1 and the largest ones order 5.
Results: Rats subjected to BCCAO and reperfusion showed: arteriolar diameter decrease, microvascular leakage, leukocyte adhesion in venules, and reduction in capillary perfusion. Pretreatment with oleuropein or pinoresinol, a higher dose before BCCAO determined dilation in all arteriolar orders RE. Microvascular leakage was reduced as well as leukocyte adhesion and ROS formation, while capillary perfusion was protected. Inhibition of endothelium nitric oxide synthase prior to oleuropein or pinoresinol reduced the effect of these polyphenols on pial arteriolar diameter and leakage. These substances, administered together, prevented microvascular damage to a larger extent.
Conclusion: Oleuropein and pinoresinol were both able to protect pial microcirculation from I-reperfusion injury, to increase nitric oxide release and to reduce oxidative stress preserving pial blood flow distribution
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
Geometric Features of the Pial Arteriolar Networks in Spontaneous Hypertensive Rats: A Crucial Aspect Underlying the Blood Flow Regulation
Full text linkBackgroundSeveral studies indicate that hypertension causes major changes in the structure of the vessel wall by affecting the regulation of blood supply to the tissues. Recently, it has been observed that capillary blood flow is also considerably influenced by the structural arrangement of the microvascular networks that undergo rarefaction (reduction of the perfused vessel number). Therefore, this study aimed to assess the geometric arrangements of the pial arteriolar networks and the arteriolar rhythmic diameter changes in spontaneously hypertensive rats (SHRs).MethodsFluorescence microscopy was utilized to observe in vivo the pial microcirculation through a closed cranial window. Pial arterioles were classified according to Strahler’s method. The arteriolar rhythmic diameter changes were evaluated by a generalization short-time Fourier transform.ResultYoung SHRs showed four orders of vessels while the adult ones only three orders. The diameter, length, and branching number obeyed Horton’s law; therefore, the vessels were distributed in a fractal manner. Larger arterioles showed more asymmetrical branches than did the smaller ones in young SHRs, while in adult SHRs smaller vessels presented asymmetrical branchings. In adult SHRs, there was a significant reduction in the cross-sectional area compared with the young SHRs: this implies an increase in peripheral resistance. Young and adult age-matched normotensive rats did not show significant alterations in the geometric arteriolar arrangement with advancing age, both had four orders of arteriolar vessels, and the peripheral resistance did not change significantly. Conversely, the frequency components evaluated in arteriolar rhythmic diameter changes of young and adult SHRs showed significant differences because of a reduction in the frequency components related to endothelial activity detected in adult SHRs.ConclusionIn conclusion, hypertension progressively causes changes in the microarchitecture of the arteriolar networks with a smaller number of vessels and consequent reduced conductivity, characteristic of rarefaction. This was accompanied by a reduction in the formation and release of independent and dependent – endothelial nitric oxide components regulating arterial vasomotion
Dietary protein intake in sarcopenic obese older women
Full text linkObjective: To determine the prevalence of sarcopenia in a population of obese older women and to assess the effect of a diet moderately rich in proteins on lean mass in sarcopenic obese older women.
Materials and methods: A total of 1,030 females, >65 years old, body mass index >30 kg/m(2), were investigated about their nutritional status. Muscle mass (MM) was estimated according to the Janssen equation (MM =0.401× height(2)/resistance measured at 50 kHz +3.825× sex -0.071× age +5.102). Sarcopenia was defined according to the MM index, MM/height2 (kg/m(2)), as two standard deviations lower than the obesity-derived cutoff score (7.3 kg/m(2)). A food-frequency questionnaire was used to measure participants' usual food intake during the previous 3 months. Moreover, a group of sarcopenic obese older women (n=104) was divided in two subgroups: the first (normal protein intake [NPI], n=50) administered with a hypocaloric diet (0.8 g/kg desirable body weight/day of proteins), and the second treated with a hypocaloric diet containing 1.2 g/kg desirable body weight/day of proteins (high protein intake [HPI], n=54), for 3 months. Dietary ingestion was estimated according to a daily food diary, self-administered, and three reports of nonconsecutive 24-hour recall every month during the follow-up.
Results: The 104 women were classified as sarcopenic. After dieting, significant reductions in body mass index were detected (NPI 30.7±1.3 vs 32.0±2.3 kg/m(2), HPI 30.26±0.90 vs 31.05±2.90 kg/m(2); P<0.01 vs baseline). The MM index presented significant variations in the NPI as well as in the HPI sarcopenic group (NPI 6.98±0.1 vs 7.10±0.2 kg/m(2), HPI 7.13±0.4 vs 6.96±0.1 kg/m(2); P<0.01 vs baseline).
Conclusion: A diet moderately rich in proteins was able to preserve MM in sarcopenic women. Therefore, adequate protein intake could contribute to the prevention of lean-mass loss associated with weight reduction in obese older people
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
Effects of Citrus Flavonoids Against Microvascular Damage Induced by Hypoperfusion and Reperfusion in Rat Pial Circulation
No full textObjective: The aim of the present study was to investigate the in vivo protective effects of hesperidin or diosmin or apigenin on damage induced by transient BCCAO and reperfusion.
Methods: Rat pial microcirculation was observed through a closed cranial window, using fluorescence microscopy. Pial arterioles were classified in five orders according to the Strahler's method.
Results: After 30 BCCAO and 60 minutes reperfusion, rats showed decreased arteriolar diameter, microvascular leakage, leukocyte adhesion, and reduction in capillary perfusion. Hesperidin and diosmin abolished the reduction in arteriolar diameter, while higher dose apigenin induced dilation by 21.7 ± 2.0% in order three arterioles RE. Nitric oxide synthase inhibition attenuated significantly hesperidin or diosmin or apigenin's effects on arteriolar diameter. Moreover, all these substances reduced microvascular leakage as well as leukocyte adhesion in dose-related manner, while capillary perfusion was protected. Furthermore, reduction in infarcted area and decrease in ROS production were observed.
Conclusions: Hesperidin, diosmin, and apigenin showed dose-related protective effects on hypoperfusion-reperfusion injury, causing nitric oxide release and attenuating tissue edema and leukocyte adhesion
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