Collagenous matrix supported by a 3D-printed scaffold for osteogenic differentiation of dental pulp cells

Objective

A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs).

Digital holographic microscopy of the myelin figure structural dynamics and the effect of thermal gradient

Myelin figures (MFs) are cylindrical multilamellar lipid tubes that can be found in various healthy and diseased living cells. Their formation and dynamics involve some of the most mysterious configurations that lipid molecules can adopt under certain conditions. They have been studied with different microscopy methods. Due to the frequent coiling of their structure, the usual methods of microscopy fail to give precise quantitative information about their dynamics. In this paper, we introduced Digital Holographic Microscopy (DHM) as a useful method to calculate the precise dynamical volume, thickness, surface and length of the myelin figures. As an example of DHM imaging of myelin figures, their structure and growth rate in the presence and absence of temperature gradient have been studied in this work. We showed that the thickness of a myelin figure can be changed during the first few seconds. However, after approximately ten seconds, the thickness stabilizes and does not alter significantly. We further studied the effect of the thermal gradient on the length growth. The calculation of the length growth from the measurement of the myelin figure volume shows that the length (L) grows in time (t) as L∝tat the early stage of the myelin protrusion in both the presence and the absence of the thermal gradient. However, thermal gradient facilitates the growth and increases its rate.OCIS codes: (090.1995) Digital holography, (090.2880) Holographic interferometry, (120.5050) Phase measurement, (160.1435) Biomaterials, (170.3880) Medical and biological imaging, (180.6900) Three-dimensional microscopy     

Comparison between fractional excretions of urea and sodium in children with acute kidney injury

Fractional excretion of sodium (FENa) has been said to be the most sensitive index for differentiating prerenal failure (PRF) from intrinsic renal failure (IRF). However, there are several instances of high FENa (>2%) in cases of PRF and low FENa (<1%) in IRF patients. In contrast, the fractional excretion of urea nitrogen (FEUN) is primarily dependent on passive forces, and many confounding variables that affect FENa have little effect on FEUN, if any. To compare FEUN with FENa, pediatric patients with acute kidney injury (AKI) were prospectively evaluated by history, physical examination, and obtaining appropriate laboratory data during a 1-year interval. Diagnosis of PRF or IRF was made in each patient, and renal failure indices were compared between two groups using chi-square and t test, as appropriate. Probability value (P value) <0.05 was considered significant. Receiver operating characteristic (ROC) plots for FEUN and FENa were drawn to compare the discriminative power of each index. Forty-three patients were enrolled in the study. There were 27 patients in the PRF and 16 in the IRF group. FENa was 2 ± 0.4 in PRF and 4.5 ± 1% in IRF patients (P < 0.05), and low FENa (<1%) was only seen in 44.4% of PRF patients, which was not statistically different from those with IRF (P > 0.05). FEUN was 23.6 ± 4.9% in PRF and 41.6 ± 4.8% in IRF patients (P < 0.05), and low FEUN (<35%) was seen in 77.8% of the PRF group (P < 0.05). Cutoff values of 30% and 1.6% were reached for FEUN and FENa, respectively. In conclusion, FEUN < 35% had higher sensitivity and specificity than FENa < 1% for differentiation of PRF from IRF.     

Synthesis and Characterization of Encapsulated Nanosilica Particles with an Acrylic Copolymer by in Situ Emulsion Polymerization Using Thermoresponsive Nonionic Surfactant

Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST) was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modification and the encapsulation in a single pot, which greatly simplified the process compared with other conventional methods requiring separate processing steps. The morphology of the encapsulated nanosilica particles was investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), which confirmed the uniform distribution of the nanoparticles without any agglomerations. A neat copolymer was also prepared as a control sample. Both the neat copolymer and the prepared nanocomposite were characterized by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analyses (TGA), dynamic mechanical thermal analysis (DMTA) and the flame resistance test. Due to the uniform dispersion of the non-agglomerated nanoparticles in the matrix of the polymer, TGA and flame resistance test results showed remarkably improved thermal stability. Furthermore, DMTA results demonstrated an enhanced storage modulus of the nanocomposite samples compared with that of the neat copolymer, indicating its superior mechanical properties.     

Absence of kl-vs variant of klotho gene in Iranian cardiac patients (comparison to the world populations)

Objective: Klotho has an important role in development of coronary artery (CAD) disease. A functional variant of klotho gene (kl-vs) has been found as an independent risk factor for early-onset occult coronary artery disease (CAD) in previous studies. The Frequency of this variant was not known in Iranian population. We have examined the allele frequency of the kl-vs variant in a case-control study in an Iranian population. Methods and results: Genotyping for kl-vs variant was carried out in N=107 individuals including N=54 cases and N=53 control who all underwent coronary angiogram for CAD evaluation. Patients with >50% stenosis in vessels considered as case groups (or CAD^{+}) and patients with normal vessels (or CAD^{-}) as controls. The frequency of kl-vs variant was determined in these patients using PCR-RFLP technique. None of the individual was carrying the kl-vs mutation in our samples. The frequency of kl-vs mutation was significantly different from previous studies in different populations. Conclusion: The kl-vs variant seems to be scare found in the Iranian population in comparison to other populations reported previously. Klotho gene might be a candidate gene of atherosclerosis in some populations but not in Iranian population. Further studies are required to examine the frequency of kl-vs variant in other populations from the Middle East.     

Multiplexed microarrays based on optically encoded microbeads

In recent years, there has been growing interest in optically-encoded or tagged functionalized microbeads as a solid support platform to capture proteins or nucleotides which may serve as biomarkers of various diseases. Multiplexing technologies (suspension array or planar array) based on optically encoded microspheres have made possible the observation of relatively minor changes in biomarkers related to specific diseases. The ability to identify these changes at an early stage may allow the diagnosis of serious diseases (e.g. cancer) at a time-point when curative treatment may still be possible. As the overall accuracy of current diagnostic methods for some diseases is often disappointing, multiplexed assays based on optically encoded microbeads could play an important role to detect biomarkers of diseases in a non-invasive and accurate manner. However, detection systems based on functionalized encoded microbeads are still an emerging technology, and more research needs to be done in the future. This review paper is a preliminary attempt to summarize the state-of-the-art concerning diagnostic microbeads; including microsphere composition, synthesis, encoding technology, detection systems, and applications.     

Nasal eosinophilia as a marker for allergic rhinitis: a controlled study of 50 patients

Eosinophils are the principal effector cells involved in the pathogenesis of allergic inflammation. We conducted a study to investigate the validity of the nasal smear examination for detecting eosinophilia in patients with allergic rhinitis. Our study group was made up of 50 patients with allergic rhinitis and 50 age- and sex-matched controls without allergic rhinitis. Smears were obtained from nasal secretions in both groups and then fixed, stained, and studied under light microscopy. Statistical analysis revealed that the odds ratio for eosinophilia positivity in nasal smears in the rhinitis group was 25.61 with a 95% confidence interval of 8 to 78. The sensitivity, specificity, positive predictive value, and negative predictive value of this test were 74, 90, 88, and 77%, respectively. We conclude that the nasal eosinophilia test is highly specific and moderately sensitive in diagnosing allergic rhinitis, and that it therefore can be used as an easy, noninvasive, and inexpensive procedure for screening patients and for conducting epidemiologic studies of this disorder.