64 research outputs found

    Serum YKL-40 levels as a novel marker of inflammation in patients with endometriosis

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    WOS: 000359512600019PubMed: 26411218Purpose: To establish serum YKL-40 concentrations in patients with endometriosis compared to age-matched healthy subjects. Materials and Methods: This was a cross-sectional clinical study conducted in a tertiary care center. Demographics and serum YKL levels were determined and noted in a total of 63 cases (33 endometriosis patients, 30 healthy controls). Measurement of YKL-40 levels was made using a YKL-40 enzyme-linked immunosorbent assay (ELISA) kit according to the manufacturer's protocol. Results: the mean serum YKL-40 levels of the patient group was 106.0 +/- 15.9 (range 23.44 to 382.55) years, while the mean serum YKL-40 levels of the controls was 52.2 +/- 7.0 (range 22.35 to 160.0) years (p = 0.003). Conclusions: This is the first study evaluating serum YKL-40 levels in endometriosis. the present results indicate that YKL-40 levels were increased in patients with endometriosis compared to controls. the authors propose that circulating YKL-40 levels could be a novel biomarker for diagnosis and follow-up of endometriosis

    Alteration of maternal serum irisin levels in gestational diabetes mellitus

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    Objectives: The aim of our study was to compare serum irisin concentrations in pregnant women with and without ges­tational diabetes mellitus (GDM). Material and methods: This study was performed at the Tertiary Care Center, Department of Obstetrics and Gynecol­ogy, between January 2014 and April 2014. A total of 45 pregnant women with GDM (diabetes group) and 41 BMI- and age-matched healthy pregnant women (control group) were recruited. Maternal serum irisin levels were measured by enzyme-linked immunosorbent assay kit at 24–28 weeks of gestation. An association between maternal serum irisin lev­els and metabolic parameters was analyzed. Body mass index, serum levels of glucose, insulin and irisin were tested and analyzed in the study group and controls. Results: Pregnant women with GDM had significantly higher fasting plasma glucose (p = 0.001), first-hour OGTT glucose (p = 0.001), second-hour OGTT glucose (p = 0.001), and fasting insulin (p = 0.045) levels as compared to controls. Serum irisin levels were 1.04 ± 0.3 and 1.3 ± 0.2 in pregnant women with GDM and healthy pregnant controls, respectively (p = 0.001). Correlation analysis between irisin levels and anthropometric and biochemical parameters in patients with gestational diabetes revealed that none of the investigated parameters correlated with serum irisin level. Conclusions: Our results suggest that serum irisin levels might be introduced as a novel marker for GDM, with decreased levels of irisin being indicative of GDM

    A Comparative Study: Taxonomic Grouping of Alkaline Protease Producing Bacilli

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    Alkaline proteases have biotechnological importance due to their activity and stability at alkaline pH. 56 bacteria, capable of growing under alkaline conditions were isolated and their alkaline protease activities were carried out at different parameters to determine their optimum alkaline protease production conditions. Seven isolates were showed higher alkaline protease production capacity than the reference strains. The highest alkaline protease producing isolates (103125 U/g), E114 and C265, were identified as Bacillus licheniformis with 99.4% and Bacillus mojavensis 99.8% based on 16S rRNA gene sequence similarities, respectively. Interestingly, the isolates identified as Bacillus safensis were also found to be high alkaline protease producing strains. Genotypic characterizations of the isolates were also determined by using a wide range of molecular techniques (ARDRA, ITS-PCR, (GTG)5-PCR, BOX-PCR). These different techniques allowed us to differentiate the alkaliphilic isolates and the results were in concurrence with phylogenetic analyses of the 16S rRNA genes. While ITS-PCR provided the highest correlation with 16S rRNA groups, (GTG)5-PCR showed the highest differentiation at species and intra-species level. In this study, each of the biotechnologically valuable alkaline protease producing isolates was grouped into their taxonomic positions with multi-genotypic analyses

    Biofabrication of in situ self assembled 3D cell cultures in a weightlessness environment generated using magnetic levitation

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    Magnetic levitation though negative magnetophoresis is a novel technology to simulate weightlessness and has recently found applications in material and biological sciences. Yet little is known about the ability of the magnetic levitation system to facilitate biofabrication of in situ three dimensional (3D) cellular structures. Here, we optimized a magnetic levitation though negative magnetophoresis protocol appropriate for long term levitated cell culture and developed an in situ 3D cellular assembly model with controlled cluster size and cellular pattern under simulated weightlessness. The developed strategy outlines a potential basis for the study of weightlessness on 3D living structures and with the opportunity for real-time imaging that is not possible with current ground-based simulated weightlessness techniques. The low-cost technique presented here may offer a wide range of biomedical applications in several research fields, including mechanobiology, drug discovery and developmental biology.Scientific and Technological Research Council of Turkey (215S862

    Dose-response curve of a microfluidic magnetic bead-based surface coverage sandwich assay

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    Magnetic micro-and nanoparticles ('magnetic beads') have been used to advantage in many microfluidic devices for sensitive antigen (Ag) detection. Today, assays that use as read-out of the signal the number count of immobilized beads on a surface for quantification of a sample's analyte concentration have been among the most sensitive and have allowed protein detection lower than the fg mL(-1) concentration range. Recently, we have proposed in this category a magnetic bead surface coverage assay (Tekin et al., 2013 [1]), in which 'large' (2.8 mm) antibody (Ab)-functionalized magnetic beads captured their Ag from a serum and these Ag-carrying beads were subsequently exposed to a surface pattern of fixed 'small' (1.0 mm) Ab-coated magnetic beads. When the system was exposed to a magnetic induction field, the magnet dipole attractive interactions between the two bead types were used as a handle to approach both bead surfaces and assist with Ag-Ab immunocomplex formation, while unspecific binding (in absence of an Ag) of a large bead was reduced by exploiting viscous drag flow. The dose-response curve of this type of assay had two remarkable features: (i) its ability to detect an output signal (i.e. bead number count) for very low Ag concentrations, and (ii) an output signal of the assay that was non-linear with respect to Ag concentration. We explain here the observed dose-response curves and show that the type of interactions and the concept of our assay are in favour of detecting the lowest analyte concentrations (where typically either zero or one Ag is carried per large bead), while higher concentrations are less efficiently detected. We propose a random walk process for the Ag-carrying bead over the magnetic landscape of small beads and this model description explains the enhanced overall capture probability of this assay and its particular non-linear dose response curves. Research Pape

    Chaotic mixing using source-sink microfluidic flows in a PDMS chip

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    We present an active fixed-volume mixer based on the creation of multiple source–sink microfluidic flows in a polydimethylsiloxane (PDMS) chip without the need of external or internal pumps. To do so, four different pressure-controlled actuation chambers are arranged on top of the 5 μl volume of the mixing chamber. After the mixing volume is sealed/fixed by microfluidic valves made using ‘microplumbing technology’, a virtual source–sink pair is created by pressurizing one of the membranes and, at the same time, releasing the pressure of a neighboring one. The pressurized air deforms the thin membrane between the mixing and control chambers and creates microfluidic flows from the squeezed region (source) to the released region (sink) where the PDMS membrane is turned into the initial state. Several schemes of operation of virtual source–sink pairs are studied. In the optimized protocol, mixing is realized in just a sub-second time interval, thanks to the implementation of chaotic advection

    Microfluidic-based virus detection methods for respiratory diseases

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    With the recent SARS-CoV-2 outbreak, the importance of rapid and direct detection of respiratory disease viruses has been well recognized. The detection of these viruses with novel technologies is vital in timely prevention and treatment strategies for epidemics and pandemics. Respiratory viruses can be detected from saliva, swab samples, nasal fluid, and blood, and collected samples can be analyzed by various techniques. Conventional methods for virus detection are based on techniques relying on cell culture, antigen-antibody interactions, and nucleic acids. However, these methods require trained personnel as well as expensive equipment. Microfluidic technologies, on the other hand, are one of the most accurate and specific methods to directly detect respiratory tract viruses. During viral infections, the production of detectable amounts of relevant antibodies takes a few days to weeks, hampering the aim of prevention. Alternatively, nucleic acid–based methods can directly detect the virus-specific RNA or DNA region, even before the immune response. There are numerous methods to detect respiratory viruses, but direct detection techniques have higher specificity and sensitivity than other techniques. This review aims to summarize the methods and technologies developed for microfluidic-based direct detection of viruses that cause respiratory infection using different detection techniques. Microfluidics enables the use of minimal sample volumes and thereby leading to a time, cost, and labor effective operation. Microfluidic-based detection technologies provide affordable, portable, rapid, and sensitive analysis of intact virus or virus genetic material, which is very important in pandemic and epidemic events to control outbreaks with an effective diagnosis.Qatar National Research Fun

    Magnetic Particle-Scanning for Ultrasensitive Immunodetection On-Chip

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    We describe the concept of magnetic particle-scanning for on-chip detection of biomolecules: a magnetic particle, carrying a low number of antigens (Ag's) (down to a single molecule), is transported by hydrodynamic forces and is subjected to successive stochastic reorientations in an engineered magnetic energy landscape. The latter consists of a pattern of substrate-bound small magnetic particles that are functionalized with antibodies (Ab's). Subsequationuent counting of the captured Ag-carrying particles provides the detection signal. The magnetic particle-scanning principle is investigated in a custom-built magneto-microfluidic chip and theoretically described by a random walk-based model, in which the trajectory of the contact point between an Ag-carrying particle and the small magnetic particle pattern is described by stochastic moves over the surface of the mobile particle, until this point coincides with the position of an Ag, resulting in the binding of the particle. This model explains the particular behavior of previously reported experimental dose-response curves obtained for two different ligand-receptor systems (biotin/streptavidin and TNF-alpha) over a wide range of concentrations. Our model shows that magnetic particle-scanning results in a very high probability of irrununocomplex formation for very low Ag concentrations, leading to an extremely low limit of detection, down to the single molecule-per-particle level. When compared to other types of magnetic particle-based surface coverage assays, our strategy was found to offer a wider dynamic range (>8 orders of magnitude), as the system does not saturate for concentrations as high as 10(11) Ag molecules in a 5 mu L drop. Furthermore, by emphasizing the importance of maximizing the encounter probability between the Ag and the Ab to improve sensitivity, our model also contributes to explaining the behavior of other particle-based heterogeneous immunoassays
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