94 research outputs found
A comparison of melatonin and α-lipoic acid in the induction of antioxidant defences in L6 rat skeletal muscle cells.
Aging is characterized by a progressive deterioration in physiological functions and metabolic processes. The loss of cells during aging in vital tissues and organs is related to several factors including oxidative stress and inflammation. Skeletal muscle degeneration is common in elderly people; in fact, this tissue is particularly vulnerable to oxidative stress since it requires large amounts of oxygen, and thus, oxidative damage is abundant and accumulates with increasing age. Melatonin (N-acetyl-5-methoxytryptamine) is a highly efficient scavenger of reactive oxygen species and it also exhibits beneficial anti-inflammatory and anti-aging effects. This study investigated the susceptibility of rat L6 skeletal muscle cells to an induced oxidative stress following their exposure to hydrogen peroxide (50 ÎĽM) and evaluating the potential protective effects of pre-treatment with melatonin (10 nM) compared to the known beneficial effect of alpha-lipoic acid (300 ÎĽM). Hydrogen peroxide-induced obvious oxidative stress; it increased the expression of tumour necrosis factor-alpha and in turn promoted nuclear factor kappa-B and overrode the endogenous defence mechanisms. Conversely, pre-treatment of the hydrogen peroxide-exposed cells to melatonin or alpha-lipoic acid increased endogenous antioxidant enzymes, including superoxide dismutase-2 and heme oxygenase-1; moreover, they ameliorated significantly oxidative stress damage and partially reduced alterations in the muscle cells, which are typical of aging. In conclusion, melatonin was equally effective as alpha-lipoic acid; it exhibited marked antioxidant and anti-aging effects at the level of skeletal muscle in vitro even when it was given in a much lower dose than alpha-lipoic acid
Implementing Multiblock Techniques in a full-scale plant scenario: On-line Prediction of Quality Parameters in a Continuous Process for Different Acrylonitrile Butadiene Styrene (ABS) Products
Background
The study explores the challenges of handling multiblock data of different natures (process and NIR sensors) for on-line quality prediction in a full-scale plant scenario, namely a plant operating in continuous on an industrial scale and producing different grade Acrylonitrile Butadiene Styrene (ABS) products. This environment is an ideal scenario to evaluate the use of multiblock data analysis methods, which can enhance data interpretation, visualization, and predictive performances. In particular, a novel multiblock extension of Locally Weighted PLS has been proposed by the authors, namely Locally Weighted Multiblock Partial Least Squares (LW-MB-PLS). Response-Oriented Sequential Alternation (ROSA) has also been employed to evaluate the diverse block relevance for the prediction of two quality parameters associated with the polymer. Data are split in blocks both according to sensor type and different plant sections, and different models have been built by incremental addition of data blocks to evaluate if early estimation of product quality is feasible.
Results
ROSA method showed promising predictive performance for both quality parameters, highlighting the most influential plant sections through the selection of data blocks. The results suggested that both early and late-stage sensors play crucial roles in predicting product quality. A reasonable estimation of quality parameters before production completion has been achieved. On the other hand, the proposed LW-MB-PLS, while comparable in predictive performances, allowed reducing systematic prediction errors for specific products.
Significance
This study contributes valuable insights for continuous production processes, aiding plant operators and paving the way for advancements in online quality prediction and control. Furthermore, it is implemented as a locally weighted extension of MB-PLS
Real Time Quality Assessment of General Purpose Polystyrene (GPPS) by means of Multiblock-PLS Applied on On-line Sensors Data
In the petrochemical industry, in order to control the final product quality over time and to detect potential plant
failures, the amount of lab (off-line) analysis performed every day is very demanding in terms of resources and
time. Hence, at/in-line monitoring can be an efficient solution to decrease chemical wastes and operators’ efforts
and to perform a fast detection of deviations from normal operative conditions. Moving toward this
implementation requires both installation of analytical sensors and the development of models capable to predict
in real time the quality parameters of the polymers based on both process and analytical sensors. The primary
aim of the current work has been the development of real time monitoring models by advanced chemometric
tools for the prediction of a General Purpose PolyStyrene (GPPS) quality property, fusing Near Infrared (NIR)
and process sensors data. In the plant considered, in addition to standard process sensors, along the GPPS
production line, operating in continuous, two NIR probes are installed in-line. After the arrangement of the
available data in different blocks, aiming at studying the specific contribution of the two types of sensors and of
the main phases of the process, Multiblock-PLS (MB-PLS) method was employed to fuse the different blocks
and to assess which were the most relevant sensors and plant phases for the prediction of the two quality
parameters. Good prediction performances were achieved, allowing identifying the most significant data blocks
for the GPPS quality prediction. Moreover, prediction errors obtained by models computed without considering
blocks of data belonging to the final stages of the process were similar to those involving all the available data
blocks. Therefore, a good real time assessment of the GPPS quality can be obtained even before the production
is completed, which is very promising in view of minimizing the number of off-line laboratory analyse
A Multiblock Approach to Fuse Process and Near-Infrared Sensors for On-Line Prediction of Polymer Properties
Petrochemical companies aim at assessing final product quality in real time, in order to rapidly deal with possible plant faults and to reduce chemical wastes and staff effort resulting from the many laboratory analyses performed every day. In order to answer these needs, the main purpose of the current work is to explore the feasibility of multiblock regression methods to build real-time monitoring models for the prediction of two quality properties of Acrylonitrile-Butadiene-Styrene (ABS) by fusing near-infrared (NIR) and process sensors data. Data come from a production plant, which operates continuously, and where four NIR probes are installed on-line, in addition to standard process sensors. Multiblock-PLS (MB-PLS) and Response-Oriented Sequential Alternation (ROSA) methods were here utilized to assess which of such sensors and plant areas were the most relevant for the quality parameters prediction. Several prediction models were constructed exploiting measurements provided by sensors active at different ABS production process stages. Both methods provided good prediction performances and permitted identification of the most relevant data blocks for the quality parameters’ prediction. Moreover, models built without considering recordings from the final stage of the process yielded prediction errors comparable to those involving all available data blocks. Thus, in principle, allowing final ABS quality to be estimated in real-time before the end of the process itself
Aging of brain in hypercholesterolemic mice (ApoE -/-): melatonin receptor distribution
The protective role of melatonin has been investigated [1]. Some studies underlined its significant neuroprotective action with a role in aging processing. In patients with Alzheimer’s Disease, parallel to degenerative tissue changes, there was an overall decrease in the intensity of melatonin receptors in the pineal gland and occipital cortex [2]. Melatonin type 1 (MT1) and type 2 (MT2) receptors disclosed a quite widespread distribution in different brain regions. Recently our group demonstrated that an animal model of hypercholesterolemia, such as ApoE-/- mice, is more susceptible to developing severe liver injury, suggesting that in addition to vascular disease, increased cholesterol products and oxidative stress may also play a role in accelerating aging in the liver [3]. On the basis of this consideration, the aim of our work is to characterize the distribution of MT1 and MT2 in brain of ApoE -/- mice at different age (6 weeks, 16 weeks and 60 weeks) together with senescence markers using immunohistochemical technique to verify the role of these receptors in aging process. The results show an altered distribution of melatonin receptors and synaptic connectivity, indicating a process of aging in ApoE -/- mice and suggesting that melatonin treatment may represent a new approach to reduce brain aging and degeneration
H2O2 stress damage is reversed by melatonin in a spinal cord organotypic model
Spinal cord injury (SCI) is characterized to be a two-step process: the primary lesion consisting of the initial trauma; the secondary damage, characterized by multiple processes including inflammation, oxidative stress and cell death that lead to a significant expansion of the original damage and to an increase of the functional deficit (1). Among the aforementioned processes, the oxidative stress plays a significant role in pathophysiology of SCI. In this study, we evaluated the role of the melatonin, an indoleamine recognized as a potent antioxidant and immunomodulator (2, 3 )Reiter et al., 1995, Favero et al., 2015), on the oxidative stress, the tissue vitality and the neuritic plasticity in an experimental model of organotypic cultures of Sprague Dawley rat spinal cord slice (SPS) treated with hydrogen peroxide (H2O2) and/or melatonin. Five experimental protocols were performed: 1) control; 2) H2O2 exposure (50 ÎĽM); 3) melatonin treatment (5-10M for 24 hours); 4) H2O2 exposure and post-treatment with melatonin; 5) H2O2 exposure after pre-treatment with melatonin. Cellular death was investigated by propidium iodide (PI) assay and the vitality by MTT assay. The total thiols (SH) levels, contrasting the oxidative stress, the neuronal specific nuclear protein (NeuN) and the synaptophysin (Syp) immunopositivity were also evaluated. Melatonin significantly decreases the number of dead cells and increases slice vitality, mainly in slices treated before H2O2 exposure. Moreover, melatonin attenuates total thiols decrease and NeuN and Syp immunopositivity reduction. Overall, these findings suggest that melatonin may exert a potential beneficial effect upon the progression of SCI secondary damage, protecting the tissue from a further degeneration.This work was supported by grants from Giorgio Brunelli Foundation for Spinal Cord Injuries Research
Epithelial expression of vanilloid and cannabinoid receptors: a potential role in burning mouth syndrome pathogenesis
Burning mouth syndrome is an intraoral burning sensation in which the oral mucosa has a normal appearance and no medical or dental causes can be found. It remains an unknown disease for which long-term treatment is still lacking. The aim of this study is to assess in epithelial human tongue the expression of three receptors involved in pain transmission, such as a transient receptor potential vanilloid receptor type 1 (TRPV1) which mediates the sensation produced by chilli peppers, cannabinoid receptors type 1 (CB1) and type 2 (CB2), which are pathway-related to TRPV1. Epithelial cells express TRPV1, CB1 and CB2 receptors suggesting a role for these cells in sensory transduction. The study was performed on 8 healthy and 9 BMS patients. All patients underwent a 3-mm punch biopsy at the anterolateral aspect of the tongue close to the tip. Specimens were included in paraffin and serially cut to obtain 6um thick sections. The sections were processed for TRPV1, CB1 and CB2 immunohistochemistry. The analysis showed an altered expression of the studied receptors. In particular we observed an increase of TRPV1, a decrease of CB1 and an increase of CB2 expression in epithelial cells of the tongue with a change in morphological localization. So, these receptors seem to be correlated with BMS. These data could be useful for future characterization of BMS markers and specific therapies
Platelet Rich Plasma stimulates human hair growth in vitro
Several factors are involved in hair growth and cycling (Buffoli et al., 2013). Platelet concentrates have a new important role in regenerative medicine and thus in dermatology, oral, plastic and orthopaedic surgery and hair growth (Franco et al., 2012). In this study we evaluated in vitro the effects of Platelet-Rich Plasma (PRP), an autologous platelet preparation, on hair growth. In particular, we compared four different culture media (Philpott et al., 1990): 1-William’s E culture medium with supplemented factors; 2-William’s E culture medium with supplemented factors and Platelet Rich Plasma; 3-William’s E culture medium without supplemented factors; 4-William’s E culture medium without supplemented factors but with PRP. Hair shaft elongation was measured at 0, 24, 48, 72 and 96 hours: digitally fixed images of slices were analyzed using an image analyzer considering as measurable portion the shaft part between the bulb upper border and the top of the hair end. The values obtained were used to calculate the percentage of elongation for each time. Growth in hair cultured with William’s E medium with supplemented factors and PRP resulted higher with respect to the other media. Moreover, these results suggest that PRP stimulates human hair growth in vitro
Sirtuin 6 localization at cortical brain level of young diabetic mice
The metabolic syndrome, characterized by visceral obesity, dyslipidaemia, hyperglycaemia and hypertension, has become one of the major public-health challenges worldwide and it is strictly associated with the development of type II diabetes and neurodegenerative diseases (Alberti et al. 2005; Panza et al. 2010). Increased metabolic flux to the brain during overnutrition can orchestrate stress response, blood-brain barrier alteration, microglial cells activation and neuroinflammation (Nerurkar et al., 2011). The protein sirtuin family is a class of nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase that act on a variety of targets and so play a key role in central physiological regulation (Sebastian et al., 2012; Wang et al., 2012). To assess the physiopathological significance of sirtuin6 (SIRT6) at brain cortical level, we analysed its specific expression and subcellular localization in young db/db mice, animal model of type II diabetes mellitus, and respective control lean mice. In particular, we analysed the cytoarchitecture of the brain cortex, evaluated SIRT6 expression and its localization by immunohistochemistry comparing young db/db mice to lean control mice, distinguishing among the six cortical layers and between motor and somatosensory cortex. We observed that SIRT6 is mainly localized in the nucleus of both lean and db/db mice. Diabetic mice showed few SIRT6 positive cells respect to lean control mice in all cortical layers without significant differences between motor and somatosensory cortex. No morphological alteration have been find. In conclusion, our findings contribute to further understand SIRT6 protein expression in the early steps of type II diabetes mellitus and suggest its implication in the pathogenic processes of diabetes mellitus and diabetes–induced neurodegeneration
Sirtuin 6 localization at cortical brain level of young diabetic mice
The metabolic syndrome, characterized by visceral obesity, dyslipidaemia, hyperglycaemia and hypertension, has become one of the major public-health challenges worldwide and it is strictly associated with the development of type II diabetes and neurodegenerative diseases (Alberti et al. 2005; Panza et al. 2010). Increased metabolic flux to the brain during overnutrition can orchestrate stress response, blood-brain barrier alteration, microglial cells activation and neuroinflammation (Nerurkar et al., 2011). The protein sirtuin family is a class of nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylase that act on a variety of targets and so play a key role in central physiological regulation (Sebastian et al., 2012; Wang et al., 2012). To assess the physiopathological significance of sirtuin6 (SIRT6) at brain cortical level, we analysed its specific expression and subcellular localization in young db/db mice, animal model of type II diabetes mellitus, and respective control lean mice. In particular, we analysed the cytoarchitecture of the brain cortex, evaluated SIRT6 expression and its localization by immunohistochemistry comparing young db/db mice to lean control mice, distinguishing among the six cortical layers and between motor and somatosensory cortex. We observed that SIRT6 is mainly localized in the nucleus of both lean and db/db mice. Diabetic mice showed few SIRT6 positive cells respect to lean control mice in all cortical layers without significant differences between motor and somatosensory cortex. No morphological alteration have been find. In conclusion, our findings contribute to further understand SIRT6 protein expression in the early steps of type II diabetes mellitus and suggest its implication in the pathogenic processes of diabetes mellitus and diabetes–induced neurodegeneration
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