2,715 research outputs found
Effects of intradermal injection of atrial natriuretic peptide.
Abstract
Atrial natriuretic peptide (ANP) causes mast cell degranulation in rats in vivo and in vitro but is bronchodilator in humans. The aim of this study was to investigate the wheal and flare dose-response to intradermal injection of alpha-human ANP in normal humans. Eight normal subjects received five 30 microliters injections containing 1, 10, 39, 78, 117 pmol ANP and one each of normal saline, histamine 675 pmol and substance P 30 pmol. Maximum ANP flare response was greater but not significantly than that to saline at 1.55 +/- 0.6 (mean +/- s.e. mean) compared with 0.42 +/- 0.17 cm2, but much less than to histamine 9.86 +/- 0.97 or to substance P 12.5 +/- 1.2. Maximum ANP wheal response was significantly greater than that to saline at 0.38 +/- 0.08 compared with 0.18 +/- 0.05 cm2 (difference between means 0.20, 95% CI 0.05, 0.35), but much less than to histamine 0.75 +/- 0.06 or to substance P 1.05 +/- 0.08 cm2. No dose-response to ANP was demonstrated, though responses to the highest dose differed significantly from those to the lowest dose studied. We conclude that human cutaneous responses to ANP differ from those of animals and that the skin is less responsive than other tissues in humans
Developing a Relative Humidity Correction for Low-Cost Sensors Measuring Ambient Particulate Matter.
There is increasing concern about the health impacts of ambient Particulate Matter (PM) exposure. Traditional monitoring networks, because of their sparseness, cannot provide sufficient spatial-temporal measurements characteristic of ambient PM. Recent studies have shown portable low-cost devices (e.g., optical particle counters, OPCs) can help address this issue; however, their application under ambient conditions can be affected by high relative humidity (RH) conditions. Here, we show how, by exploiting the measured particle size distribution information rather than PM as has been suggested elsewhere, a correction can be derived which not only significantly improves sensor performance but which also retains fundamental information on particle composition. A particle size distributionâ»based correction algorithm, founded on Îș -Köhler theory, was developed to account for the influence of RH on sensor measurements. The application of the correction algorithm, which assumed physically reasonable Îș values, resulted in a significant improvement, with the overestimation of PM measurements reduced from a factor of ~5 before correction to 1.05 after correction. We conclude that a correction based on particle size distribution, rather than PM mass, is required to properly account for RH effects and enable low cost optical PM sensors to provide reliable ambient PM measurements
Identifying dynamical modules from genetic regulatory systems: applications to the segment polarity network
BACKGROUND
It is widely accepted that genetic regulatory systems are 'modular', in that the whole system is made up of smaller 'subsystems' corresponding to specific biological functions. Most attempts to identify modules in genetic regulatory systems have relied on the topology of the underlying network. However, it is the temporal activity (dynamics) of genes and proteins that corresponds to biological functions, and hence it is dynamics that we focus on here for identifying subsystems.
RESULTS
Using Boolean network models as an exemplar, we present a new technique to identify subsystems, based on their dynamical properties. The main part of the method depends only on the stable dynamics (attractors) of the system, thus requiring no prior knowledge of the underlying network. However, knowledge of the logical relationships between the network components can be used to describe how each subsystem is regulated. To demonstrate its applicability to genetic regulatory systems, we apply the method to a model of the Drosophila segment polarity network, providing a detailed breakdown of the system.
CONCLUSION
We have designed a technique for decomposing any set of discrete-state, discrete-time attractors into subsystems. Having a suitable mathematical model also allows us to describe how each subsystem is regulated and how robust each subsystem is against perturbations. However, since the subsystems are found directly from the attractors, a mathematical model or underlying network topology is not necessarily required to identify them, potentially allowing the method to be applied directly to experimental expression data
Distress levels of parents of children with neurodevelopmental disorders during the COVID-19 pandemic: A comparison between Italy and Australia
Parents of children with a neurodevelopmental disorder (NDD) report higher levels of distress compared to those of typically developing children. Distress levels may be heightened by the restrictions associated with the COVID-19 pandemic. However, it is unclear whether distress levels of parents varied by the diagnosis of neurodevelopmental disorder in children during the COVID-19 pandemic. This study aims to investigate whether parental distress was influenced by the type of NDD. Participants were from Australia (N = 196) and Italy (N = 200); the parents of children aged 3â18 were invited to complete an online self-reported survey which included the 6-item Kessler Psychological Distress Scale (K6) to determine parental distress. The results show that intellectual or learning disorder (ILD) is a major contributor to parental distress compared to other NDDs in both Australia and Italy. Moreover, the worsening of symptomatic changes in children with NDDs was significantly associated with parental distress. The differences between the two countries in terms of the pandemic impact, however, were not statistically significant. The results suggest that intervention strategies need to be tailored for individual clinical information and factor in the societyâs stringency level of anti-contagion policies to improve parental wellbeing
The value of immunohistochemical research on PCNA, p53 and heat shock proteins in prostate cancer management: a review.
This review addresses the significance of the expression of proliferating cell nuclear antigen (PCNA), p53 and some heat shock proteins (Hsps) in prostate carcinoma (PC). In fact, PCNA and p53 are two widely discussed tools in PC diagno- sis, mainly because of the controversy regarding the signifi- cance of their expression during prostate cancer development and progression. At the same time, only few studies have shown the potential role of Hsps in carcinogenesis and their overexpression in pre-neoplastic and neoplastic lesions of the prostate. We briefly describe the physiological roles of Hsps in normal cells, and the significance of their immunohistochem- ical detection in PC as well as in pre-cancerous lesions of the prostate. We will also discuss the possible functional interac- tions of these molecules in both dysplastic and neoplastic cell
Quality of life, alexithymia, and defence mechanisms in patients affected by breast cancer across different stages of illness
Objectives: The aim of this study was to evaluate the effect of alexithymia and defence mechanisms on the quality of life of patients affected by breast cancer at different stages of the disease.
Methods A convenience sample of 110 patients with breast cancer was involved in the study: 41 were receiving adjuvant chemotherapyafter surgery, 29 had disease-free survival in follow-up and 40 were receiving chemotherapy for metastatic disease. Quality of life, alexithymia and defence mechanisms were assessed using the following instruments: EORTC QLQ-C30-BR23, Toronto Alexithymia Scale (TAS-20) and Defense Mechanism Inventory (DMI). Results Compared to the other groups, patients receiving chemotherapy for metastatic disease reported poorer quality of life in several domains, more severe cancer-related and treatment-related symptoms and higher levels of alexithymia. When the effect of other potential predictors was taken into account, TAS-20 difficulty in identifying feelings was significantly related to all the EORTC functional subscale.
Conclusion: This study underlined the relevance of difficulty in emotional processing and defence mechanisms in modulating psychological adjustment in women affected by breast cancer, suggesting that these might be potential targets of psychological intervention for this population
A generalized deep learning network for fractional anisotropy reconstruction: Application to epilepsy and multiple sclerosis
Fractional anisotropy (FA) is a quantitative map sensitive to microstructural properties of tissues in vivo and it is extensively used to study the healthy and pathological brain. This map is classically calculated by model fitting (standard method) and requires many diffusion weighted (DW) images for data quality and unbiased readings, hence needing the acquisition time of several minutes. Here, we adapted the U-net architecture to be generalized and to obtain good quality FA from DW volumes acquired in 1 minute. Our network requires 10 input DW volumes (hence fast acquisition), is robust to the direction of application of the diffusion gradients (hence generalized), and preserves/improves map quality (hence good quality maps). We trained the network on the human connectome project (HCP) data using the standard model-fitting method on the entire set of DW directions to extract FA (ground truth). We addressed the generalization problem, i.e., we trained the network to be applicable, without retraining, to clinical datasets acquired on different scanners with different DW imaging protocols. The network was applied to two different clinical datasets to assess FA quality and sensitivity to pathology in temporal lobe epilepsy and multiple sclerosis, respectively. For HCP data, when compared to the ground truth FA, the FA obtained from 10 DW volumes using the network was significantly better (p <10-4) than the FA obtained using the standard pipeline. For the clinical datasets, the network FA retained the same microstructural characteristics as the FA calculated with all DW volumes using the standard method. At the subject level, the comparison between white matter (WM) ground truth FA values and network FA showed the same distribution; at the group level, statistical differences of WM values detected in the clinical datasets with the ground truth FA were reproduced when using values from the network FA, i.e., the network retained sensitivity to pathology. In conclusion, the proposed network provides a clinically available method to obtain FA from a generic set of 10 DW volumes acquirable in 1 minute, augmenting data quality compared to direct model fitting, reducing the possibility of bias from sub-sampled data, and retaining FA pathological sensitivity, which is very attractive for clinical applications
Psychological principles of successful aging technologies: A mini-review
Based on resource-oriented conceptions of successful life-span development, we propose three principles for evaluating assistive technology: (a) net resource release; (b) person specificity, and (c) proximal versus distal frames of evaluation. We discuss how these general principles can aid the design and evaluation of assistive technology in adulthood and old age, and propose two technological strategies, one targeting sensorimotor and the other cognitive functioning. The sensorimotor strategy aims at releasing cognitive resources such as attention and working memory by reducing the cognitive demands of sensory or sensorimotor aspects of performance. The cognitive strategy attempts to provide adaptive and individualized cuing structures orienting the individual in time and space by providing prompts that connect properties of the environment to the individual's action goals. We argue that intelligent assistive technology continuously adjusts the balance between `environmental support' and `self-initiated processing' in person-specific and aging-sensitive ways, leading to enhanced allocation of cognitive resources. Furthermore, intelligent assistive technology may foster the generation of formerly latent cognitive resources by activating developmental reserves (plasticity). We conclude that `lifespan technology', if co-constructed by behavioral scientists, engineers, and aging individuals, offers great promise for improving both the transition from middle adulthood to old age and the degree of autonomy in old age in present and future generations. Copyright (C) 2008 S. Karger AG, Basel
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