135 research outputs found
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The Effect of Amnion-derived Cellular Cytokine Solution on the Epithelialization of Partial-thickness Donor Site Wounds in Normal and Streptozotocin-induced Diabetic Swine
Objective: The purpose of this study was to determine whether amnion-derived cellular cytokine solution (ACCS) could improve the quality of epithelialization and accelerate closure of dermatome-created partial-thickness wounds in normal and streptozotocin-induced diabetic pigs. Methods: Dermatome-created partial-thickness wounds were sealed with wound chambers in healthy and diabetic pigs and were injected with ACCS. Wound fluid was exchanged daily for total protein concentration, and biopsies were taken on days 6, 8, 10, and 12. Epithelialization, thickness of epidermis, number of epidermal cell layers, and rete ridges were evaluated. Results: The macroscopic appearance of the wounds and speed of healing was similar in all groups at each time point. All wounds were healed by day 6. The epidermis was thicker in the ACCS-treated diabetic wounds than in the controls (140.6 μm vs 82.7 μm on day 12 in diabetic pigs). There were more cell layers (13 vs 7.7) in ACCS-treated diabetic pigs on day 12. The number of rete ridges per 2.5 mm was greater on day 12 in the ACCS-treated diabetic wounds (13 vs 8). There was also a significant increase in the number of rete ridges in ACCS-treated nondiabetic pigs but no difference in epidermal thickness or number of cell layers. Conclusion: In diabetic pigs, we found a significantly thicker epidermis and more cell layers and rete ridges in the ACCS-treated wounds. Healthy pigs showed more rete ridges but no difference in thickness of epidermis or number of cell layers on day 12
Comparison of coronal discoloration induced by White MTA and CEM Cement
Coronal discoloration of endodontically treated teeth is a challenge in clinical dentistry. This study aimed to compare coronal discoloration induced by White Mineral Trioxide Aggregate and Calcium-enriched mixture cement. Fifty single-rooted, unrestored premolar teeth extracted for orthodontic reasons were selected. After access cavity preparation, all the root canals were instrumented with MTWO rotary files up to #40.6%. The specimens were randomly assigned to two experimental groups, White Mineral Trioxide Aggregate and Calcium-enriched mixture cement groups (n = 20), and two control groups (n = 5). In the White Mineral Trioxide Aggregate and Calcium-enriched mixture cement groups, the material was condensed via the access cavity 3 mm below the cementoenamel junction to a thickness of 3 mm. Tooth color was assessed using computer analysis of digital images. Tooth color measurements were recorded at eight time intervals: before material placement (but after tooth preparation), at 24 h, 48 h, one week, two weeks, four weeks, eight weeks, and sixteen weeks after material placement. Data were analyzed using t-test, ANOVA, repeated measure ANOVA, and Tukey HSD tests. The significance level was set at 5% for all the tests. Cervical discoloration of teeth in both experimental groups significantly increased over time (p < 0.05). However, samples in the White Mineral Trioxide Aggregate group showed more discoloration in cervical regions than Calcium-enriched mixture cement specimens after two, four, eight, and sixteen weeks (p < 0.05). Applying both White Mineral Trioxide Aggregate and Calcium-enriched mixture cement induced coronal discoloration; however, White Mineral Trioxide Aggregate samples exhibited greater cervical discoloration than Calcium-enriched mixture cement specimens after two, four, eight, and sixteen weeks
A new glucocerebrosidase-deficient neuronal cell model provides a tool to probe pathophysiology and therapeutics for Gaucher disease
Glucocerebrosidase is a lysosomal hydrolase involved in the breakdown of glucosylceramide. Gaucher disease, a recessive lysosomal storage disorder, is caused by mutations in the gene GBA1. Dysfunctional glucocerebrosidase leads to accumulation of glucosylceramide and glycosylsphingosine in various cell types and organs. Mutations in GBA1 are also a common genetic risk factor for Parkinson disease and related synucleinopathies. In recent years, research on the pathophysiology of Gaucher disease, the molecular link between Gaucher and Parkinson disease, and novel therapeutics, have accelerated the need for relevant cell models with GBA1 mutations. Although induced pluripotent stem cells, primary rodent neurons, and transfected neuroblastoma cell lines have been used to study the effect of glucocerebrosidase deficiency on neuronal function, these models have limitations because of challenges in culturing and propagating the cells, low yield, and the introduction of exogenous mutant GBA1. To address some of these difficulties, we established a high yield, easy-to-culture mouse neuronal cell model with nearly complete glucocerebrosidase deficiency representative of Gaucher disease. We successfully immortalized cortical neurons from embryonic null allele gba(-/-) mice and the control littermate (gba(+/+)) by infecting differentiated primary cortical neurons in culture with an EF1 alpha-SV40T lentivirus. Immortalized gba(-/-) neurons lack glucocerebrosidase protein and enzyme activity, and exhibit a dramatic increase in glucosylceramide and glucosylsphingosine accumulation, enlarged lysosomes, and an impaired ATP-dependent calcium-influx response; these phenotypical characteristics were absent in gba(+/+) neurons. This null allele gba(-/-) mouse neuronal model provides a much-needed tool to study the pathophysiology of Gaucher disease and to evaluate new therapies
Impaired Rho GTPase activation abrogates cell polarization and migration in macrophages with defective lipolysis
Infiltration of monocytes and macrophages into the site of inflammation is critical in the progression of inflammatory diseases such as atherosclerosis. Cell migration is dependent on the continuous organization of the actin cytoskeleton, which is regulated by members of the small Rho GTPase family (RhoA, Cdc42, Rac) that are also important for the regulation of signal transduction pathways. We have recently reported on reduced plaque formation in an atherosclerotic mouse model transplanted with bone marrow from adipose triglyceride lipase-deficient (Atgl−/−) mice. Here we provide evidence that defective lipolysis in macrophages lacking ATGL, the major enzyme responsible for triacylglycerol hydrolysis, favors an anti-inflammatory M2-like macrophage phenotype. Our data implicate an as yet unrecognized principle that insufficient lipolysis influences macrophage polarization and actin polymerization, resulting in impaired macrophage migration. Sustained phosphorylation of focal adhesion kinase [due to inactivation of its phosphatase by elevated levels of reactive oxygen species (ROS)] results in defective Cdc42, Rac1 and RhoA activation and in increased and sustained activation of Rac2. Inhibition of ROS production restores the migratory capacity of Atgl−/− macrophages. Since monocyte and macrophage migration are a prerequisite for infiltrating the arterial wall, our results provide a molecular link between lipolysis and the development of atherosclerosis
Evaluating CPT and CPTu based pile bearing capacity estimation methods using Urmiyeh Lake Causeway piling records
AbstractUrmiyeh Lake is the largest super salt water situated in the north-west of Iran. A causeway embankment has been constructed in the narrowest part of the lake from both sides about 13.5 km, in order to connect two provincial capital cities of Tabriz and Urmiyeh of eastern and western Azerbaijan provinces to Europe through Turkey, while a 1280 m opening in between linked up by a bridge. Based on soil classification methods, utilizing CPTu data and soil sampling, the lake sediments consist of 150 m of soft and very sensitive clay. In order to evaluate the bearing capacity of driven piles of the bridge, eight long steel piles with diameters of 813 and 66 m and lengths of 75 m have been instrumented and monitored based on static and dynamic load testing program. Piezocone (CPTu) results are also available from adjacent pile locations. Results of pile capacity calculation based on direct CPT and CPTu methods demonstrate that reasonable accuracy can be achieved in reference to dynamic testing. Therefore, combination of CPTu data with dynamic testing results can be considered by engineers for predicting bearing capacity of piles in offshore and bridge structures, where the static pile load testing is difficult, time consuming and expensive in marine environment
The influence of single-sided ventilation towards the indoor thermal performance of high-rise residential building: A field study
Adequate designed ventilation systems can be an alternative technique to create better thermal conditions in buildings. Unlike cross ventilation, single-sided ventilation mode which is highly applicable in high-rise residential buildings has been not taken into account extensively in previous studies to determine its influence on indoor thermal conditions. The current study aims to fulfill the gap by evaluation of this type of ventilation mode in the tropical climate. Building orientation and height as two crucial factors that may impact the ventilation mode were concerned in a field experiment to achieve reliable outcomes. The field experiment was carried out in a seventeen story residential building in Kuala Lumpur to analyze the influence of single-sided ventilation mode on indoor air temperature, relative humidity and air velocity according to the sun path analysis. This found that a living room located on a higher floor facing the prevailing wind achieves approximately 90% thermal acceptability at a mean air velocity of 0.52 ms−1. Further analysis between the best and worst scenarios revealed that indoor air temperature and relative humidity were influenced by orientation and height, with the air velocity in the living room in the best scenario being almost eight times higher than same room in the worst scenario. Multiple comparisons of rooms by post hoc tests showed significantly different mean air temperatures and air velocities in most of the cases, and hence confirmed the effects of orientation and height on these variables. However, the study explored that internal space division can counteract the role of orientation in such cases. Thus, along with building orientation, interior layout should be taken into account in the analysis of indoor thermal conditions in future studies. Finally, the study recommended further studies on the direct influence of air velocity on air temperature in single-sided ventilated unit due to some drawbacks in existing studies
Determination of Zinc Ions in Environmental Samples by Dispersive Liquid- Liquid Micro Extraction and Atomic Absorption Spectroscopy
<div><p>In this work preconcentration of the Zn ions was investigated in water sample by Dispersive liquid- liquid micro extraction (DLLME) using chloroform as an extraction solvent, methanol as a disperser solvent and 8-Hydroxyquinoline as a chelating agent. The determination of extracted ions was done by graphite furnace atomic absorption spectrometry. The influence of various analytical parameters including pH, extraction and disperser solvent type and volume and concentration of the chelating agent on the extraction efficiency of analyses was investigated. After extraction, the enrichment factor was 26 and the detection limit of the method was 0.0033 µg l<sup>-1</sup> and the relative standard deviations (R.S.D) for five determinations of 1 ng/ml Zn were 7.41%.</p><p> </p></div
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