1,628 research outputs found
Aldosterone induces cardiotrophin-1 expression in HL-1 adult cardiomyocytes
Aldosterone (ALDO) may induce cardiac hypertrophy by nonhemodynamic mechanisms that are not completely defined. Cardiotrophin-1 (CT-1) is a cytokine that exerts hypertrophic actions on isolated cardiomyocytes and promotes cardiac hypertrophy in vivo. We investigated whether ALDO induces CT-1 expression in HL-1 cardiomyocytes aiming at the possibility that the cytokine is involved in ALDO-induced cardiomyocyte hypertrophy. mRNA and protein expression were quantified by RT-PCR and Western blot. Cardiomyocyte area, as an index of hypertrophy, was assayed by image analysis in phalloidin-stained HL-1 cells. ALDO addition to adult HL-1 cardiomyocytes increased (P<0.01) CT-1 mRNA and protein expression in a concentration-dependent manner. This effect was abrogated by actinomycin D, the mineralocorticoid and glucocorticoid receptor antagonists spironolactone and RU486, respectively, and the p38 MAPK blocker SB203580. CT-1 signaling pathway blockade with specific antibodies against the cytokine and its two receptor subunits avoided (P<0.01) alpha-sarcomeric actin and c-fos protein overexpression as well as cell size increase induced by ALDO in HL-1 cells. In vivo, a single ALDO injection acutely increased (P<0.01) the myocardial expression of CT-1 in C57BJ6 wild-type mice but not CT-1-null mice. The bolus of the mineralocorticoid increased (P<0.01) ANP and c-fos mRNA expression in the myocardium of wild-type mice, whereas no changes were observed in CT-1-null mice. In summary, ALDO induces CT-1 expression in adult HL-1 cardiomyocytes via genomic and nongenomic mechanisms. CT-1 up-regulation could have relevance in the direct hypertrophic effects of ALDO in cardiomyocytes
Mach-Zehnder-based measurement of light emitting diodes temporal coherence
Objectives: The main objective of this work is to validate a Mach-Zehnder based interferometric method to measure the temporal coherence length of broadband finite size light sources such as Light Emitting Diodes (LEDs), and give a qualitative value of the temporal coherence length of white LEDs, for which nor their spectral width neither their emission peak wavelength are clearly defined. Motivation: Low-coherence light sources such as LEDs have opened many possibilities in applications in which using lasers introduces coherent noise (speckle) that hinders the performance of interferometric measurement techniques. The coherence length is an important characteristic of light sources for scientific applications related to diffraction, holography, tomography, or interferometry. The spatial coherence of a source depends on the distance from the source to the observation plane and its size, while the temporal coherence is related to the emission spectral width and the emission peak wavelength. Therefore, the temporal coherence is a characteristic of each source. Methodology and results: In this work, we use a Mach-Zehnder interferometer for the first time to measure the coherence degree and the temporal coherence length of quasi-monochromatic LEDs. We validate the technique by comparing the results to those obtained directly from the spectrum. Then, we use the tested interferometric method to measure the temporal coherence length of a white LED, for which neither the width of the spectrum nor the emission peak wavelength, are clearly defined. In this case, the Wiener-Khinchin theorem is used to validate the interferometric technique. A very interesting property of the method is that the temporal coherence length is obtained from a single measurement, without needing to perform a scanning. This method can be used also for other non-coherent sources such as halogen lamps, pulsed lasers, and so on. The obtained results will improve the characterization of light sources and the applications dealing with physical optics and electromagnetic interference. © 2022 The Author
The BIDIAP index: a clinical, analytical and ultrasonographic score for the diagnosis of acute appendicitis in children
Background: Pediatric acute appendicitis (PAA) continues to be a diagnostic challenge today. The diagnostic performance of classical indices is only moderate, especially in pediatric population. This study aimed to define a clinical, radiological and analytical index for the diagnosis of PAA.
Materials and methods: This prospective study included 151 patients divided into two groups: (1) 53 patients with non-surgical abdominal pain (NSAP) and (2) 98 patients with a confirmed PAA. Sociodemographic and clinical characteristics were compared between groups using the Mann-Whitney U test and the Fisher exact test. To identify the predictors of PAA, we performed a multivariable logistic regression using a forward stepwise analysis and we assigned multiples of integer values to the selected variables. The diagnostic performance of the index was assessed by calculating the area under the receiver operating characteristic curve. Intra-cohort calibration was assessed with the Hosmer-Lemeshow test.
Results: We developed the BIDIAP index (BIomarkers for the DIagnosis of Appendicitis in Pediatrics), which included three variables that independently predicted higher odds of PAA: appendiceal caliber (≥ 6.9 mm), systemic immune-inflammation index (≥ 890) and peritoneal irritation, which scored 4, 3 and 2 points, respectively. Mean (SD) score of the participants was 2.38 (2.06) in group 1 and 7.89 (1.50) in group 2. The area under the ROC was 0.97 (95% CI 0.95-0.99). The cut-off point was established at 4 points, resulting in a sensitivity of 98.98% and a specificity of 77.78%.
Conclusions: The BIDIAP index has an exceptional diagnostic performance in PAA. The importance of these results lies in its novelty and in the simplicity of the index. Although external validation will be necessary, initial results look promising
Alterations and diagnostic performance of capillary ketonemia in pediatric acute appendicitis: a pilot study
Introduction: The diagnostic performance of capillary ketonemia (CK) has been previously evaluated in context of pediatric acute gastroenteritis. To our knowledge, there is no literature on its performance in the setting of pediatric acute appendicitis (PAA).
Materials and methods: In this study, 151 patients were prospectively included and divided into two groups: (1) patients with non-surgical abdominal pain in whom the diagnosis of PAA was excluded (n : 53) and (2) patients with a confirmed diagnosis of PAA (n : 98). In 80 patients (Group 1, n : 23 and group 2, n : 57) a CK was measured at the time of diagnosis. The PAA group was further classified into complicated (n : 18) and uncomplicated PAA (n : 39). Quantitative variables were compared between groups using the Mann-Whitney U test. Diagnostic performance of CK was evaluated with ROC curves.
Results: CK values were 0.3 [0.1-0.9] mmol/L in group 1 and 0.7 [0.4-1.4] mmol/L in group 2 (p = 0.01). Regarding the type of PAA, CK values were 0.6 [0.4-0.9] mmol/L in uncomplicated PAA and 1.2 [0.8-1.4] mmol/L in complicated PAA (p : 0.02). The AUC for the discrimination between groups 1 and 2 was 0.68 (95/100 IC 0.53-0.82) (p : 0.24) and the AUC for the discrimination between uncomplicated PAA and complicated PAA was 0.69 (95/100 IC 0.54-0.85) (p : 0.04). The best cut-off point (group 1 vs group 2) resulted in 0.4 mmol/L, with a sensitivity of 80.7/100 and a specificity of 52.2/100. The best cut-off point (non-complicated vs complicated PAA) resulted in 1.1 mmol/L, with a sensitivity of 61.1/100 and a specificity of 76.9/100.
Conclusions: This study found significantly higher levels of CK in patients with PAA than in those with NSAP. Similarly, significantly higher levels were observed in patients with complicated than in those with uncomplicated PAA. Nevertheless, the diagnostic performance of CK was only moderate in the two settings analyzed. The potential usefulness of CK determination as a tool to guide the preoperative rehydration regimen of patients with PAA to prevent postoperative hyporexia and vomiting is a promising line of research and should be evaluated in future studies
Leucine-Rich Alpha-2-Glycoprotein as a non-invasive biomarker for pediatric acute appendicitis: a systematic review and meta-analysis
The aim of this study was to analyze the diagnostic performance of Leucine-Rich Alpha-2-Glycoprotein (LRG1) in pediatric
acute appendicitis (PAA). We conducted a systematic review of the literature in the main databases of medical bibliography.
Two independent reviewers selected the articles and extracted relevant data. Methodological quality was assessed using
the QUADAS2 index. A synthesis of the results, standardization of the metrics and 4 random-effect meta-analyses were
performed. Eight studies with data from 712 participants (305 patients with confirmed diagnosis of PAA and 407 controls)
were included in this review. The random-effect meta-analysis of serum LRG1 (PAA vs control) resulted in a significant
mean difference (95% CI) of 46.76 μg/mL (29.26–64.26). The random-effect meta-analysis for unadjusted urinary LRG1
(PAA vs control) resulted in a significant mean difference (95% CI) of 0.61 μg/mL (0.30–0.93). The random-effect metaanalysis (PAA vs control) for urinary LRG1 adjusted for urinary creatinine resulted in a significant mean difference (95%
CI) of 0.89 g/mol (0.11–1.66).
Conlusion: Urinary LRG1 emerges as a potential non-invasive biomarker for the diagnosis of PAA. On the other hand,
due to the high between-study heterogeneity, the results on serum LRG1 should be interpreted with caution. The only study
that analyzed salivary LRG1 showed promising results. Further prospective studies are needed to confirm these findings
Absence of cardiotrophin 1 is associated with decreased age-dependent arterial stiffness and increased longevity in mice
Cardiotrophin 1 (CT-1), an interleukin 6 family member, promotes fibrosis and arterial stiffness. We hypothesized
that the absence of CT-1 influences arterial fibrosis and stiffness, senescence, and life span. In senescent 29-month-
old mice, vascular function was analyzed by echotracking device. Arterial histomorphology, senescence, metabolic,
inflammatory, and oxidative stress parameters were measured by immunohistochemistry, reverse transcription polymerase
chain reaction, Western blot, and ELISA. Survival rate of wild-type and CT-1–null mice was studied. Vascular smooth
muscle cells were treated with CT-1 (10
−9
mol/L) for 15 days to analyze senescence. The wall stress-incremental elastic
modulus curve of old CT-1–null mice was shifted rightward as compared with wild-type mice, indicating decreased
arterial stiffness. Media thickness and wall fibrosis were lower in CT-1–null mice. CT-1–null mice showed decreased
levels of inflammatory, apoptotic, and senescence pathways, whereas telomere-linked proteins, DNA repair proteins,
and antioxidant enzyme activities were increased. CT-1–null mice displayed a 5-month increased median longevity
compared with wild-type mice. In vascular smooth muscle cells, chronic CT-1 stimulation upregulated apoptotic and
senescence markers and downregulated telomere-linked proteins. The absence of CT-1 is associated with decreased
arterial fibrosis, stiffness, and senescence and increased longevity in mice likely through downregulating apoptotic,
senescence, and inflammatory pathways. CT-1 may be a major regulator of arterial stiffness with a major impact on the
aging proces
Diagnostic performance of serum pentraxin-3 in pediatric acute appendicitis: a prospective diagnostic validation study
Introduction
Pediatric acute appendicitis (PAA) is a pathology with a high rate of diagnostic error. The search for new diagnostic tools is justified by the high morbidity and healthcare costs associated with diagnostic error.
Methods
We designed a prospective study to validate serum pentraxin-3 (PTX3) as a diagnostic tool in PAA. Participants were divided into three groups: (1) patients with no underlying pathology (2) patients with non-surgical abdominal pain and (3) patients with a confirmed diagnosis of PAA. For further analyses, patients in group 3 were divided into complicated or uncomplicated PAA. Quantitative variables were expressed as medians and interquartile ranges and categorical variables as percentages. Quantitative variables were compared using the Kruskal–Wallis test and the Mann–Whitney U test. Diagnostic performance was evaluated with ROC curves.
Results
This study included 215 patients divided into group 1 (n : 63), group 2 (n : 53) and group 3 (n : 99). Median serum PTX3 values were 2.54 (1.70–2.95) ng/mL, 3.29 (2.19–7.64) ng/mL and 8.94 (6.16–14.05) in groups 1, 2 and 3, respectively (p : 0.001). Patients with complicated PAA showed significantly higher values than patients with uncomplicated PAA (p = 0.04). The AUC (group 2 vs. 3) was 0.77 (95/100 CI 0.69–0.85) and the best cut-off point was at 7.28 ng/mL, with a sensitivity of 61.3/100 and a specificity of 73.1/100. The AUC (complicated vs. uncomplicated PAA) was 0.65 (95/100 CI 0.54–0.77) and the best cut-off point was 12.33 ng/mL, with a sensitivity of 51.72/100 and a specificity of 72.73/100.
Conclusions
The diagnostic ability of serum PTX3 in PAA is only moderate and therefore it cannot be considered a definitive diagnostic test. The discriminatory ability of PTX3 between complicated and uncomplicated PAA is poor. These findings, which contrast with those reported to date, should be validated with future properly designed prospective studies
La galectina-3, una nueva diana terapéutica para las alteraciones cardiovasculares asociadas al desarrollo de la estenosis aórtica severa
Aortic stenosis is one of the most common heart
valve diseases, as well as one of the most common causes of heart failure in the elderly. Currently, there are no
medical therapies to prevent or slow the progression of
the disease. When symptoms develop alongside severe
aortic stenosis, there is a poor prognosis unless aortic
valve replacement is performed. Aortic stenosis is a heterogeneous disease with a complex pathophysiology involving structural and biological changes of the valve, as
well as adaptive and maladaptive compensatory changes in the myocardium and vasculature in response to
chronic pressure overload. Galectin-3 serves important
functions in numerous biological activities including cell
growth, apoptosis, differentiation, inflammation and fibrosis. With evidence emerging to support the function
of Galectin-3, the current review aims to summarize the
latest literature regarding the potential of Galectin-3 as
therapeutic target in aortic valve and cardiovascular alterations associated with aortic stenosis.La estenosis aórtica severa degenerativa (EA) es
una enfermedad muy prevalente, cuya incidencia se
incrementará en los próximos años debido al envejecimiento de la población. Actualmente no existe ningún
tratamiento farmacológico que retarde su progresión
y, cuando aparecen los síntomas, la cirugía de recambio valvular es la única opción. La EA se caracteriza
por la calcificación de la válvula aórtica y por la aparición de fibrosis miocárdica. Sin embargo, no se conocen los mecanismos fisiopatológicos de la EA necesarios para identificar y desarrollar nuevas estrategias
terapéuticas adecuadas. La Galectina-3 (Gal-3) regula
funciones biológicas como el crecimiento, la diferenciación, la apoptosis, la inflamación o la fibrosis. Esta
revisión resume los principales trabajos que describen
el potencial de la Gal-3 como diana terapéutica para
las alteraciones cardíacas y valvulares asociadas con
el desarrollo de EA
Fish introductions and light modulate food web fluxes in tropical streams: a whole-ecosystem experimental approach
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (N-15) stable isotope tracer to compare basal resource treatments (thinned canopy vs. control) and consumer treatments (guppy introduction vs. control). The thinned canopy stream had higher primary production than the natural canopy control, leading to increased N fluxes to invertebrates that feed on benthic biofilms (grazers), fine benthic organic matter (collector-gatherers), and organic particles suspended in the water column (filter feeders). Stream reaches with guppies also had higher primary productivity and higher N fluxes to grazers and filter feeders. In contrast, N fluxes to collector-gatherers were reduced in guppy introduction reaches relative to upstream controls. N fluxes to leaf-shredding invertebrates, predatory invertebrates, and the other fish species present (Hart\u27s killifish, Anablepsoides hartii) did not differ across light or guppy treatments, suggesting that effects on detritus-based linkages and upper trophic levels were not as strong. Effect sizes of guppy and canopy treatments on N flux rates were similar for most taxa, though guppy effects were the strongest for filter feeding invertebrates while canopy effects were the strongest for collector-gatherer invertebrates. Combined, these results extend previous knowledge about top-down and bottom-up controls on ecosystems by providing experimental, reach-scale evidence that both pathways can act simultaneously and have equally strong influence on nutrient fluxes from inorganic pools through primary consumers
Isoprenylcysteine Carboxylmethyltransferase-Based Therapy for Hutchinson-Gilford Progeria Syndrome
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