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Stroke remains an important health challenge. Here, we study whether circulating chemokine (C-C motif) ligand 5 (CCL5) levels may predict clinical outcomes for stroke patients. A total of 100 consecutive stroke patients (36 acute ischemic and 64 hemorrhagic) were admitted to the stroke unit. Clinical history data and monitoring parameters were recorded. Blood serum was collected at days 0, 1, and hospital discharge to measure CCL5 levels by ELISA. Infarct or hemorrhagic volume, neurological severity (NIHSS), and functional prognosis (mRankin scale) were measured as clinical outcomes. CCL5 levels were lower in patients with hemorrhagic stroke than in patients with acute ischemic stroke. No differences were found between females and males in both types of stroke. Ischemic stroke patients whose infarct volume grew had lower CCL5 levels at day 0. Levels of CCL5 in ischemic and hemorrhagic patients were not associated with more severe symptoms/worse prognosis (NIHSS > 3; mRankin > 2) at admission or at 3 months. CCL5 could be used as a diagnostic marker to distinguish between ischemic and hemorrhagic strokes. Furthermore, CCL5 levels could predict the infarct volume outcomes in ischemic patients.
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Isquemia Encefálica , Acidente Vascular Cerebral Hemorrágico , AVC Isquêmico , Acidente Vascular Cerebral , Quimiocina CCL5 , Feminino , Humanos , Infarto , AVC Isquêmico/complicações , Masculino , Índice de Gravidade de Doença , Volume SistólicoRESUMO
In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (GV ) and height (GH ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO2 effects on GV and GH were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (Ndep ) effects were repeatedly observed in GV and GH ; the positive effects of Ndep on canopy height growth rates, which tended to level off at Ndep values greater than approximately 1.0 g m-2 y-1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites.
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Fagus/crescimento & desenvolvimento , Nitrogênio/metabolismo , Teorema de Bayes , Demografia , Florestas , Itália , Modelos Biológicos , Nitrogênio/análise , Temperatura , Fatores de TempoRESUMO
Gene expression is an inherently noisy process. Fluctuations arise at many points in the expression of a gene, as all the salient reactions such as transcription, translation, and mRNA degradation are stochastic processes. The fluctuations become important when the cellular copy numbers of the relevant molecules (mRNA or proteins) are low. For regulated genes, a computational complication arises from the fact that protein synthesis rates depend on the concentrations of the transcription factors that regulate the corresponding genes. Because of the growing cell volume, such rates are effectively time-dependent. We deal with the effects of volume growth computationally using a rather simple method: the growth of the cell volume is incorporated in our simulations by stochastically adding small volume elements to the cell volume. As an application of this method we study a gene circuit with positive autoregulation that exhibits bistability. We show how the region of bistability becomes diminished by increasing the effect of noise via a reduced copy number of the regulatory protein. Cell volume determines the region of bistability for different noise strengths. The method is general and can also be applied to other cases where synthesis rates of proteins are regulated and an appropriate analytical description is difficult to achieve.
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Regulação da Expressão Gênica/fisiologia , Modelos Genéticos , Animais , Divisão Celular/genética , Tamanho Celular , Biologia Computacional/métodos , Replicação do DNA/genética , Redes Reguladoras de Genes , Homeostase/genética , Biossíntese de Proteínas/genética , Processos EstocásticosRESUMO
Backgrounds and purpose: Identifying the underlying cause of acute middle cerebral artery occlusion (MCAO) as intracranial atherosclerotic stenosis (ICAS) or embolism is essential for determining the optimal treatment strategy before endovascular thrombectomy. We aimed to evaluate whether baseline computed tomography perfusion (CTP) characteristics could differentiate ICAS-related MCAO from embolic MCAO. Methods: We conducted a retrospective analysis of the clinical and baseline CTP data from patients who underwent endovascular thrombectomy for acute MCAO between January 2018 and December 2022. Core volume growth rate was defined as core volume on CTP divided by onset to CTP time. Multivariate logistic analysis was utilized to identify independent predictors for ICAS-related acute MCAO, and the diagnostic performance of these predictors was evaluated using receiver operating characteristic curve analysis. Results: Among the 97 patients included (median age, 71 years; 60% male), 31 (32%) were diagnosed with ICAS-related MCAO, and 66 (68%) had embolism-related MCAO. The ICAS group was younger (p = 0.002), had a higher proportion of males (p = 0.04) and smokers (p = 0.001), a lower prevalence of atrial fibrillation (AF) (p < 0.001), lower NIHSS score at admission (p = 0.04), smaller core volume (p < 0.001), slower core volume growth rate (p < 0.001), and more frequent core located deep in the brain (p < 0.001) compared to the embolism group. Multivariate logistic analysis identified core volume growth rate (aOR 0.46, 95% CI 0.26-0.83, p = 0.01) as an independent predictor of ICAS-related MCAO. A cutoff value of 2.5 mL/h for core volume growth rate in predicting ICAS-related MCAO was determined from the receiver operating characteristic curve analysis, with a sensitivity of 81%, specificity of 80%, positive predictive value of 66%, and negative predictive value of 90%. Conclusion: Slow core volume growth rate identified on baseline CTP can predict ICAS-related MCAO. Further prospective studies are warranted to confirm and validate these findings.
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Many biological systems are coated by thin films for protection, selective absorption, or transmembrane transport. A typical example is the mucous membrane covering the airways, the esophagus, and the intestine. Biological surfaces typically display a distinct mechanical behavior from the bulk; in particular, they may grow at different rates. Growth, morphological instabilities, and buckling of biological surfaces have been studied intensely by approximating the surface as a layer of finite thickness; however, growth has never been attributed to the surface itself. Here, we establish a theory of continua with boundary energies and growing surfaces of zero thickness in which the surface is equipped with its own potential energy and is allowed to grow independently of the bulk. In complete analogy to the kinematic equations, the balance equations, and the constitutive equations of a growing solid body, we derive the governing equations for a growing surface. We illustrate their spatial discretization using the finite element method, and discuss their consistent algorithmic linearization. To demonstrate the conceptual differences between volume and surface growth, we simulate the constrained growth of the inner layer of a cylindrical tube. Our novel approach towards continua with growing surfaces is capable of predicting extreme growth of the inner cylindrical surface, which more than doubles its initial area. The underlying algorithmic framework is robust and stable; it allows to predict morphological changes due to surface growth during the onset of buckling and beyond. The modeling of surface growth has immediate biomedical applications in the diagnosis and treatment of asthma, gastritis, obstructive sleep apnoea, and tumor invasion. Beyond biomedical applications, the scientific understanding of growth-induced morphological instabilities and surface wrinkling has important implications in material sciences, manufacturing, and microfabrication, with applications in soft lithography, metrology, and flexible electronics.
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The influence of arsenazo-I additive on electrochemical anodizing of pure aluminum foil in malonic acid was studied. Aluminum dissolution increased with increasing arsenazo-I concentration. The addition of arsenazo-I also led to an increase in the volume expansion factor up to 2.3 due to the incorporation of organic compounds and an increased number of hydroxyl groups in the porous aluminum oxide film. At a current density of 15 mA·cm-2 and an arsenazo-I concentration 3.5 g·L-1, the carbon content in the anodic alumina of 49 at. % was achieved. An increase in the current density and concentration of arsenazo-I caused the formation of an arsenic-containing compound with the formula Na1,5Al2(OH)4,5(AsO4)3·7H2O in the porous aluminum oxide film phase. These film modifications cause a higher number of defects and, thus, increase the ionic conductivity, leading to a reduced electric field in galvanostatic anodizing tests. A self-adjusting growth mechanism, which leads to a higher degree of self-ordering in the arsenazo-free electrolyte, is not operative under the same conditions when arsenazo-I is added. Instead, a dielectric breakdown mechanism was observed, which caused the disordered porous aluminum oxide film structure.
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(1) Background: Vascular tissue seems to adapt towards stable homeostatic mechanical conditions, however, failure of reaching homeostasis may result in pathologies. Current vascular tissue adaptation models use many ad hoc assumptions, the implications of which are far from being fully understood; (2) Methods: The present study investigates the plausibility of different growth kinematics in modeling Abdominal Aortic Aneurysm (AAA) evolution in time. A structurally motivated constitutive description for the vessel wall is coupled to multi-constituent tissue growth descriptions; Constituent deposition preserved either the constituent's density or its volume, and Isotropic Volume Growth (IVG), in-Plane Volume Growth (PVG), in-Thickness Volume Growth (TVG) and No Volume Growth (NVG) describe the kinematics of the growing vessel wall. The sensitivity of key modeling parameters is explored, and predictions are assessed for their plausibility; (3) Results: AAA development based on TVG and NVG kinematics provided not only quantitatively, but also qualitatively different results compared to IVG and PVG kinematics. Specifically, for IVG and PVG kinematics, increasing collagen mass production accelerated AAA expansion which seems counterintuitive. In addition, TVG and NVG kinematics showed less sensitivity to the initial constituent volume fractions, than predictions based on IVG and PVG; (4) Conclusions: The choice of tissue growth kinematics is of crucial importance when modeling AAA growth. Much more interdisciplinary experimental work is required to develop and validate vascular tissue adaption models, before such models can be of any practical use.
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Previous investigations have shown that changes in total prostate volume (TPV) are highly variable among aging men, and a considerable proportion of aging men have a stable or decreasing prostate size. Although there is an abundance of literature describing prostatic enlargement in association with benign prostatic hyperplasia, less is known about the appropriate age cut-off points for TPV growth rate. In this community-based cohort study, TPV was examined once a year in men who had consecutive health checkup, during a follow-up of 4 years. A total of 5058 men (age 18-92 years old) were included. We applied multiple regression analyses to estimate the correlation between TPV growth rate and age. Overall, 3232 (63.9%) men had prostate growth, and 1826 (36.1%) had a stable or decreased TPV during the study period. The TPV growth rate was correlated negatively with baseline TPV (r=-0.32, P<0.001). Among 2620 men with baseline TPV <15 cm3, the TPV growth rate increased with age (ß=0.98, 95% CI: 0.77%-1.18%) only up to 53 years old. Among 2188 men with baseline TPV of 15-33.6 cm3, the TPV growth rate increased with age (ß=0.84, 95% CI, 0.66%-1.01%) only up to 61 years old after adjusting for factors of hypertension, obesity, baseline TPV, diabetes mellitus and dyslipidemia. In this longitudinal study, the TPV growth rate increased negatively with baseline TPV, only extending to a certain age and not beyond. Further research is needed to identify the mechanism underlying such differences in prostate growth.
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Próstata/crescimento & desenvolvimento , Hiperplasia Prostática/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Tamanho do Órgão , Próstata/patologia , Características de Residência/estatística & dados numéricosRESUMO
Imaging of malignant pleural mesothelioma is essential to patient management, prognostication, and response assessment. From animal models to clinical trials, the gamut of research activities and clinical standards relies on imaging to provide information on lesion morphology and the growing number of physiologic characteristics amenable to capture through imaging techniques. The complex morphology, growth pattern, and biological mechanisms of mesothelioma, however, present challenges for image acquisition and interpretation. Nevertheless, novel approaches to image acquisition and subsequent image analysis have expanded the opportunities for (as well as the need for) imaging in this disease. This paper summarizes the imaging-based research presented orally at the 2014 International Conference of the International Mesothelioma Interest Group (iMig) in Cape Town, South Africa, October 2014. Presented topics include the imaging of hypoxia in a murine model through positron emission tomography (PET), the use of diffusion-weighted magnetic resonance imaging (MRI) to assess the histologic composition of biphasic mesothelioma and to assess early response to chemotherapy, the correlation of CT-based tumor volume with the volume of the post-surgical tumor specimen, the development of volumetric tumor response criteria, and pre-treatment tumor volume growth considerations for tumor response assessment.
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Neoplasias Pulmonares/patologia , Mesotelioma/patologia , Neoplasias Pleurais/patologia , Animais , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Mesotelioma Maligno , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Carga Tumoral/fisiologiaRESUMO
Redwood branches provide all the carbohydrates for the most carbon-heavy forests on Earth, and recent whole-tree measurements have quantified trunk growth rates associated with complete branch inventories. Providing all of a tree's photosynthetic capacity, branches represent an increasing proportion of total aboveground wood production as trees enlarge. To examine branch development and its effects on wood volume growth, we dissected 31 branches from eight Sequoia sempervirens (D. Don) Endl. and seven Sequoiadendron giganteum Lindl. trees. The cambium-area-to-leaf-area ratio was maintained with size and age but increased with light availability, whereas the heartwood-deposition-area-to-leaf-area ratio increased with size and age but was insensitive to light availability. The proportion of foliage mass arrayed in <1-cm-diameter epicormic shoots increased with decreasing light and was higher in Sequoia (20-60%) than in Sequoiadendron (3-16%). Well-illuminated branches concentrated leaves higher and distally, while shaded branches distributed leaves lower and proximally. In similar light environments, older branches distributed leaves lower and more proximally than younger branches. Branch size, light, species, heartwood area, a heartwood-area-species interaction, and ovulate cone mass predicted 87.5% of the variability in wood volume growth of branches. After accounting for the positive effects of size and light, wood volume growth declined with heartwood area and age. The effect of age was trivial compared to the effect of heartwood area, suggesting that heartwood expansion caused the age-related decline in wood volume growth. Additionally, Sequoiadendron branches of similar size and light environment with more ovulate cones produced less wood, even though these cones were long-lived and photosynthetic, reflecting the energetic cost of seed production. These results contributed to a conceptual model of branch development in which light availability, injury, heartwood content, gravity, and time interact to produce the high degree of branch structural variation evident within redwood crowns.
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Caules de Planta/anatomia & histologia , Caules de Planta/crescimento & desenvolvimento , Sequoia/anatomia & histologia , Sequoia/crescimento & desenvolvimento , Madeira/crescimento & desenvolvimento , California , Modelos Lineares , Modelos Biológicos , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , Brotos de Planta/fisiologia , Análise de Componente Principal , Árvores/fisiologiaRESUMO
ABSTRACT The objective of this work is to identify the malignant lung nodules accurately and early with less false positives. 'Nodule' is the 3mm to 30mm diameter size tissue clusters present inside the lung parenchyma region. Segmenting such a small nodules from consecutive CT scan slices are a challenging task. In our work Auto-seed clustering based segmentation technique is used to segment all the possible nodule candidates. Efficient shape and texture features (2D and 3D) were computed to eliminate the false nodule candidates. The change in centroid position of nodule candidates from consecutive slices was used as a measure to remove the vessels. The two-stage classifier is used in this work to classify the malignant and benign nodules. First stage rule-based classifier producing 100 % sensitivity, but with high false positive of 12.5 per patient scan. The BPN based ANN classifier is used as the second-stage classifier which reduces a false positive to 2.26 per patient scan with a reasonable sensitivity of 88.8%. The Rate of Nodule Growth (RNG) was computed in our work to measure the nodules growth between the two scans of the same patient taken at different time interval. Finally, the nodule growth predictive measure was modeled through the features such as compactness (CO), mass deficit (MD), mass excess (ME) and isotropic factor(IF). The developed model results show that the nodules which have low CO, low IF, high MD and high ME values might have the potential to grow in future.
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Previous investigations have shown that changes in total prostate volume (TPV) are highly variable among aging men, and a considerable proportion of aging men have a stable or decreasing prostate size. Although there is an abundance of literature describing prostatic enlargement in association with benign prostatic hyperplasia, less is known about the appropriate age cut-off points for TPV growth rate. In this community-based cohort study, TPV was examined once a year in men who had consecutive health checkup, during a follow-up of 4 years. A total of 5058 men (age 18-92 years old) were included. We applied multiple regression analyses to estimate the correlation between TPV growth rate and age. Overall, 3232 (63.9%) men had prostate growth, and 1826 (36.1%) had a stable or decreased TPV during the study period. The TPV growth rate was correlated negatively with baseline TPV (r=-0.32, P<0.001). Among 2620 men with baseline TPV <15 cm, the TPV growth rate increased with age (β=0.98, 95% CI: 0.77%-1.18%) only up to 53 years old. Among 2188 men with baseline TPV of 15-33.6 cm, the TPV growth rate increased with age (β=0.84, 95% CI, 0.66%-1.01%) only up to 61 years old after adjusting for factors of hypertension, obesity, baseline TPV, diabetes mellitus and dyslipidemia. In this longitudinal study, the TPV growth rate increased negatively with baseline TPV, only extending to a certain age and not beyond. Further research is needed to identify the mechanism underlying such differences in prostate growth.