326 research outputs found
Cytogenetic Evaluation of Couples With Spontaneous Abortion, Still Birth and Recurrent Miscarriage in Qazvin: Report and Review
Background: Chromosomal abnormality plays an important role in different types of miscarriages.
Objectives: The present study was designed to investigation chromosomal anomalies in three groups of couples with recurrent
abortion (RA), spontaneous abortion (SA) and still birth (SB).
PatientsandMethods: In this retrospective study, the frequency of chromosomal aberrations was investigatedamong 260 couples
with miscarriage, which had referred to the cytogenetic section of a reference laboratory in Buali hospilal, Qazvin, Iran from 2009
to 2014. Metaphase spreads were analyzed using G-banding.
Results: In this study, 7.6% of couples had chromosomal aberrations including, balanced reciprocal translocations, robertsonian
translocations, inversions and sex chromosome aneuploidy. Frequency of balanced translocations was higher, specifically in couples
with SA.
Conclusions: In this investigation we showed that chromosomal abnormalities could be one of the important causes of miscarriages.
Cytogenetic evaluation of couples, which experienced different types of miscarriage, may prevent unnecessary treatments.
Keywords: Recurrent Abortion, Spontaneous Abortion, Still Birth, Chromosome Abnormalit
Effect of laser-dimpled titanium surfaces on attachment of epithelial-like cells and fibroblasts.
PurposeThe objective of this study was to conduct an in vitro comparative evaluation of polished and laserdimpled titanium (Ti) surfaces to determine whether either surface has an advantage in promoting the attachment of epithelial-like cells and fibroblast to Ti.Materials and methodsForty-eight coin-shaped samples of commercially pure, grade 4 Ti plates were used in this study. These discs were cleaned to a surface roughness (Ra: roughness centerline average) of 180 nm by polishing and were divided into three groups: SM (n=16) had no dimples and served as the control, SM15 (n=16) had 5-µm dimples at 10-µm intervals, and SM30 (n=16) had 5-µm dimples at 25-µm intervals in a 2 × 4 mm(2) area at the center of the disc. Human gingival squamous cell carcinoma cells (YD-38) and human lung fibroblasts (MRC-5) were cultured and used in cell proliferation assays, adhesion assays, immunofluorescent staining of adhesion proteins, and morphological analysis by SEM. The data were analyzed statistically to determine the significance of differences.ResultsThe adhesion strength of epithelial cells was higher on Ti surfaces with 5-µm laser dimples than on polished Ti surfaces, while the adhesion of fibroblasts was not significantly changed by laser treatment of implant surfaces. However, epithelial cells and fibroblasts around the laser dimples appeared larger and showed increased expression of adhesion proteins.ConclusionThese findings demonstrate that laser dimpling may contribute to improving the periimplant soft tissue barrier. This study provided helpful information for developing the transmucosal surface of the abutment
Pluronic F-127 hydrogel as a promising scaffold for encapsulation of dental-derived mesenchymal stem cells.
Dental-derived mesenchymal stem cells (MSCs) provide an advantageous therapeutic option for tissue engineering due to their high accessibility and bioavailability. However, delivering MSCs to defect sites while maintaining a high MSC survival rate is still a critical challenge in MSC-mediated tissue regeneration. Here, we tested the osteogenic and adipogenic differentiation capacity of dental pulp stem cells (DPSCs) in a thermoreversible Pluronic F127 hydrogel scaffold encapsulation system in vitro. DPSCs were encapsulated in Pluronic (®) F-127 hydrogel and stem cell viability, proliferation and differentiation into adipogenic and osteogenic tissues were evaluated. The degradation profile and swelling kinetics of the hydrogel were also analyzed. Our results confirmed that Pluronic F-127 is a promising and non-toxic scaffold for encapsulation of DPSCs as well as control human bone marrow MSCs (hBMMSCs), yielding high stem cell viability and proliferation. Moreover, after 2 weeks of differentiation in vitro, DPSCs as well as hBMMSCs exhibited high levels of mRNA expression for osteogenic and adipogenic gene markers via PCR analysis. Our histochemical staining further confirmed the ability of Pluronic F-127 to direct the differentiation of these stem cells into osteogenic and adipogenic tissues. Furthermore, our results revealed that Pluronic F-127 has a dense tubular and reticular network morphology, which contributes to its high permeability and solubility, consistent with its high degradability in the tested conditions. Altogether, our findings demonstrate that Pluronic F-127 is a promising scaffold for encapsulation of DPSCs and can be considered for cell delivery purposes in tissue engineering
Integration Of Mutation And Gene Expression Data To Identify Disease Subtypes
Understanding the biological insights hidden in the vast amount of data collected, while investigating a disease, is the main goal for collecting such data in the first place.
Changes in the gene expression or the function of proteins are important components in progression of a disease and is a key to understanding the disease mechanism.
However, more often than not, the causes of such changes are not easily identified. In many cases, genetic variants may cause some of the observed gene expression changes.
In this thesis, we focus on identifying the variants that significantly alter gene expression for an individual by integrating genetic variant data, gene expression data, as well as a priori knowledge about gene-gene interaction networks from multiple databases. Here we show that one can use variants that change gene expression to identify subgroups of patients with significantly different survival profiles.
The method is validated on four different cancer types (renal, lung, colorectal cancer and leukemia) from the TCGA database.
The results show that this method is able to identify variants that significantly affect the gene expression (and in turn the phenotype), as well as identify disease sub-types that are biologically meaningful as validated by survival and pathway analysis
Network-Based Approaches To Identify The Impacted Genes And Active Interactions
A very important step in system biology is the identification of the networks that are most impacted in the given phenotype.
Such networks explain where the target genes are affected by some other genes, and therefore describe the mechanisms involved in a biological process.
The identified networks are used to: 1) predict the disease or the responses of the system to a specific impact, 2) find the subset of genes that interact with each other and play an important role in the condition of interest, and 3) understand the mechanisms involved in that condition.
In this thesis, we propose an approach that takes advantage of pre-defined pathways obtained from existing databases to identify the impact of a phenotype studied on such pathways.
Next, we introduce a method able to build a network that captures the putative mechanisms at play in the given condition, by using datasets from multiple experiments studying the same phenotype. This method takes advantage of known interactions extracted from multiple sources such as protein-protein interactions and curated biological pathways. Based on such prior knowledge, we overcome the drawbacks of snap-shot data by considering the possible effects of each gene on its neighbors
Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran
Background: Over the past several years our laboratories have investigated different aspects
of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced
by physical stresses.
Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella
enterica subsp. enterica serovar Typhimurium (S. typhimurium), Staphylococcus aureus,
and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples
taken from the high background radiation areas of Ramsar, northern Iran.
Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an
indicator of the susceptibility of different bacteria to antibiotics, was used in this study.
Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae
when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in
non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD
0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of
inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested
for nitrofurantoin and cephalexin, respectively.
Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility
to antibiotics. It can be hypothesized that high levels of natural background radiation
can induce adaptive phenomena that help microorganisms better cope with lethal effects of
antibiotics
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Enhanced Osteogenic Differentiation of hMSCs Using BMP@ZIF-8-Loaded GelMA Nanocomposite Hydrogels with Controlled BMP-2 Release.
Hydrogels are highly versatile materials with immense potential for tissue engineering and regenerative medicine owing to their biocompatibility, tunable mechanical properties, and ability to mimic the natural extracellular matrix. Their 3D porous structure allows for the encapsulation and delivery of bioactive molecules, making them ideal candidates for drug delivery systems. In tissue repair, particularly for bone regeneration, hydrogels can serve as carriers that release therapeutic agents in a controlled manner, thus enhancing the healing process. Zeolitic Imidazolate Framework-8 (ZIF-8) nanoparticles and recombinant human Bone Morphogenetic Protein (rhBMP-2) molecules were incorporated solely (ZIF@GelMA) or in association (BMP@ZIF@GelMA) into gelatin modified by a methacryloyl hydrogel (GelMA) to investigate its physical and osteogenic properties. Hydrogels were characterized by Scanning Electron Microscopy and rheological tests. We analyzed hydrogel degradation and the BSA release profile of BMP@ZIF@GelMA samples throughout 0, 1, 3, 7, 14, and 28 days. Cell adhesion and bone formation markers were analyzed for hydrogel-encapsulated human dental pulp cells by using immunocytochemistry and molecular analysis. ZIF@GelMA and BMP@ZIF@GelMA exhibited a porous and viscoelastic structure with increased storage modulus when rhBMP2 was present. BSA@ZIF@GelMA showed a balanced degradation rate and a controlled release of BSA. The ZIF@GelMA upregulated the expression of cell adhesion and bone formation genes, and when BMP-2 was introduced, the levels of markers were remarkably elevated. BMP@ZIF@GelMA hydrogel presents several favorable factors to promote cellular adhesion and bone regeneration, thus encouraging further prospects for advanced therapeutic applications in tissue repair
An Efficient Adaptive Noise Cancellation Scheme Using ALE and NLMS Filters
The basic theme of our paper is to implement a new idea of noise reduction in the real time applications using the concepts of adaptive filters. Our model which is presented as one of the solutions is based on two stages of operation with the first stage based on the ALE (Adaptive Line Enhancer) filters and the second stage on NLMS (Normalized Least Mean Square) filter. The first stage reduces the sinusoidal noise from the input signal and the second stage reduces the wideband noise. Two input sources of voice are used; one for the normal speech and the other for the noise input, using separate microphones for both signals. The first signal is of the corrupted speech signal and the second signal is of only the noise containing both wideband and narrowband noise. In the first stage the narrowband noise is reduced by using the ALE technique. The second stage gets a signal with ideally only the wideband noise which is reduced using the NLMS technique. In both the stages the concerned algorithms are used to update the filter coefficients in such a way that the noise is cancelled out from the signal and a clean speech signal is heard at the output.DOI:http://dx.doi.org/10.11591/ijece.v2i3.24
Performance Evaluation of Adaptive Noise Cancellation Scheme Using ALE and NLMS Filters
The basic theme of our paper is to implement a new idea of noise reduction in the real time applications using the concepts of adaptive filters. Our model which is presented as one of the solutions is based on two stages of operation with the first stage based on the ALE (Adaptive Line Enhancer) filters and the second stage on NLMS (Normalized Least Mean Square) filter. The first stage reduces the sinusoidal noise from the input signal and the second stage reduces the wideband noise. Two input sources of voice are used; one for the normal speech and the other for the noise input, using separate microphones for both signals. The first signal is of the corrupted speech signal and the second signal is of only the noise containing both wideband and narrowband noise. In the first stage the narrowband noise is reduced by using the ALE technique. The second stage gets a signal with ideally only the wideband noise which is reduced using the NLMS technique. In both the stages the concerned algorithms are used to update the filter coefficients in such a way that the noise is cancelled out from the signal and a clean speech signal is heard at the outpu
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