Sharif Digital Repository

Rapid isolation of white blood cells (WBCs) from whole blood is an essential part of any WBC examination platform. However, most conventional cell separation techniques are labor-intensive and low throughput, require large volumes of samples, need extensive cell manipulation, and have low purity. To address these challenges, we report the design and fabrication of a passive, label-free microfluidic device with a unique U-shaped cross-section to separate WBCs from whole blood using hydrodynamic forces that exist in a microchannel with curvilinear geometry. It is shown that the spiral microchannel with a U-shaped cross-section concentrates larger blood cells (e.g., WBCs) in the inner... 

It is estimated that 20% of couples are infertile, and half of these infertility cases are linked to men. One of conditions that can affect male fertility is asthenozoospermia. We applied Raman spectroscopy to the analysis of the metabolome of the human seminal plasma, and used chemometrics on the patterns of Raman spectra obtained. Significant changes were observed in the metabolome of the human seminal plasma of asthenozoospermic patients  

A novel ion selective electrode is fabricated for naltrexone HCl and used in pharmaceutical analysis and drug determination in biological fluids without complicated pretreatments and extractions, using direct potentiometry. The naltrexone complex with sodium tetraphenyl borate (NaTPB) is obtained by in situ soaking PVC membrane electrode in an 1 × 10 -3 M naltrexone solution. The sensor exhibited fast, reproducible and linear sub-Nernstian response over concentration range of 1 × 10 -5 - 1 × 10 -3 M with a detection limit of 5 × 10 -6 M. The membrane sensor was successfully applied to the determination of naltrexone in capsules as well as for its determination in urine and plasma samples  

Isolation and characterization of circulating tumor cells (CTCs) found in blood samples of cancer patients have been considered as a reliable source for cancer prognosis and diagnosis. A new continuous microfluidic platform has been designed in this investigation for simultaneous capture and characterization of CTCs based on their deformability. The deformability-based chip (D-Chip) consists of two sections of separation and characterization where slanted weirs with a gap of 7 μm were considered. Although sometimes CTCs and leukocytes have the same size, the deformability differs in such a way that can be exploited for enrichment purposes. MCF7 and MDA-MB-231 cell lines were used for the... 

Body weight is influenced by both food intake and energy expenditure. Acylated ghrelin enhances appetite, and its circulating level is suppressed by Growth Hormone. Data on the acylated ghrelin responses to exercise of different intensities in obese individuals are currently not available. This study examined the effects of an intermittent exercise protocol on acylated ghrelin levels and hunger ratings in obese people. Nine inactive male ran on the treadmill at 0900 with progressive intensities of 50, 60, 70, and 80% of VO2max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise at 0845 (-15 min as the resting values), after each workload (10, 23, 31, and... 

Aim: The aim of this study is to look for the proper methods that would be a major step towards untreated CD diagnosis and seek the metabolic biomarkers causes of CD and compare them to control group. Background: Celiac disease (CD) is a common autoimmune disorder that is not easily diagnosed using the clinical tests. Patients and methods: Thirty cases and 30 controls were entered into this study. Metabolic profiling was obtained using proton nuclear magnetic resonance spectroscopy (1HNMR) to seek metabolites that are helpful for the detection of CD. Classification of CD and healthy subject was done using random forest (RF). Results: The obtained classification model showed an 89% correct... 

Background: Celiac disease (CD) is a disorder associated with body reaction to gluten. After the gluten intake, an immune reaction against the protein occurs and damages villi of small intestine in celiac patients gradually. Objectives: The OSC, a filtering method for minimization of inter- and intra-spectrom-eter variations that influence on data acquisition, was applied to biofluid NMR data of CD patients. Patients and Methods: In this study, metabolites of total 56 serum samples from 12 CD patients, 15 CD patients taking gluten-free diet (GFD), and 29 healthy cases were analyzed using nuclear magnetic resonance (NMR) and associated theoretical analysis. Employ-ing ProMetab (version... 

Background: Body weight is regulated by both food intake and energy expenditure. Ghrelin, a hormone produced by the stomach and pancreas, enhances appetite. This study was undertaken to determine the effects of intermittent treadmill running on acylated ghrelin and appetite in individuals with obesity. Methods: Nine inactive male students, with a mean age of 20.56±0.48 yrs, a body mass index of 32.68±0.84 kg/m2 and a maximum oxygen uptake of 34.21±1.48 ml/kg/min, participated in the study in two trials (control and exercise) in a counterbalanced, randomized design. The protocol included intermittent running with a constant intensity at 65% of VO2 max on a treadmill. Blood samples were... 

Identifying tumor cells from a pool of other cells has always been an appealing topic for different purposes. The objective of this study is to discriminate circulating tumor cells (CTCs) from blood cells for diagnostic purposes in a novel microfluidic device using two active methods: magnetophoresis and dielectrophoresis. The most specific feature of this device is the differentiation of CTCs without labeling them in order to achieve a more reliable and less complicated method. This device was analyzed and evaluated using finite element method. Four cell lines are separated in this device containing red blood cells, platelets, white blood cells, and CTCs. Primarily, red blood cells and... 

The on-fiber standardization technique for solid-coated solid-phase microextraction (SPME) was studied, and a theoretical model is proposed for the isotropic behavior of adsorption and desorption, based on Fick's law of diffusion and the Langmuir model. The isotropy of the adsorption and desorption of analytes onto and from the surface of porous solid SPME fiber was validated with the use of a commercially available fiber, a 50-μm Carbowax/ templated resin for carbamate pesticide analysis in various sample matrixes, and a self-made polypyrrole fiber for diazepam analysis in blood samples. Time constants were comparable for the adsorption and desorption processes. Equilibrium constants and... 

Recent studies have provided clues for participation of apoptosis related genes in the development of periodontitis. We examined expression of four apoptosome related genes namely CPSF7, AGO2, WDR33 and HUR1 in the blood and tissues of patients with stage III-IV periodontitis compared with control blood/tissue samples. Expression of AGO2 was significantly higher in the blood specimens of individual having periodontitis compared with healthy persons (ratio of mean expression = 6.9, P value = 4.79E−02). However, when categorizing individuals based on their gender, none of comparisons yielded significant results. Expression of AGO2 was not different between tissue samples of patients and... 

Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without... 

Background/Objectives: Curcumin, a natural polyphenol compound in the spice turmeric, has been found to have potent anti-oxidative and anti-inflammatory activity. Curcumin may treat non-alcoholic fatty liver disease (NAFLD) through its beneficial effects on biomarkers of oxidative stress (OS) and inflammation, which are considered as two feature of this disease. However, the effects of curcumin on NAFLD have been remained poorly understood. This investigation evaluated the effects of administrating curcumin on metabolic status in NAFLD patients. Subjects/Methods: Fifty-eight NAFLD patients participated in a randomized, double-blind, placebo-controlled parallel design of study. The subjects... 

The main purpose of this study is to evaluate the effect of intravenous irradiation of different low-level laser wavelengths on the activity of lecithin-cholesterol acyltransferase (LCAT), paraoxonase (PON1), catalase, and ferric reducing ability of plasma (FRAP) in diabetic rats. First, diabetes was induced in rats using streptozotocin (STZ). Enzymes’ activity was measured in the blood samples and compared before and after intravenous laser blood irradiation. We used four continuous-wave lasers—IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm), and Blue (λ = 450 nm)—to compare the wavelength’s effect on different enzymes’ activity. Laser power was fixed at 0.01 mW and laser energy was... 

An integrated microsampling approach based on solid-phase microextraction (SPME) was developed to provide a complete solution to highly efficient and accurate pharmacokinetic studies. The microsampling system included SPME probes that are made of poly(ethylene glycol) (PEG) and C18-bonded silica, a fast and efficient sampling strategy with accurate kinetic calibration, and a high-throughput desorption device based on a modified 96-well plate. The sampling system greatly improved the quantitative capability of SPME in two ways. First, the use of the C18-bonded silica/PEG fibers minimized the competition effect from analogues of the target analytes in a complicated sample matrix such as blood... 

The NF-κB family includes some transcription factors which have important functions in the regulation of immune responses, therefore participating in the pathophysiology of inflammatory conditions such as peripheral neuropathies. We have quantified expression of a number of NF-κB-related transcripts in patients with Guillain-Barré syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP) versus healthy subjects. These transcripts have been previously shown to be functionally related with this family of transcription factors. Expressions of ATG5, DICER-AS1, PACER, DILC, NKILA and ADINR have been increased in both CIDP and GBS patients compared with controls. However,... 

The electrochemical behavior of lamotrigine (LMT) at the pyrolytic graphite electrode (PGE) is investigated in detail by the means of cyclic voltammetry. During the electrochemical reduction of LMT, an irreversible cathodic peak appeared. Cyclic voltammetric studies indicated that the reduction process has an irreversible and adsorption-like behavior. The observed reduction peak is attributed to a two-electron process referring to the reduction of azo group. The electrode showed an excellent electrochemical activity toward the electro-reduction of LMT, leading to a significant improvement in sensitivity as compared to the glassy carbon electrode. The results of electrochemical impedance... 

In this study, cellulose acetate (CA) fibers were prepared using different solvent systems in electrospinning. The recorded scanning electron microscopy micrographs indicated that the morphology of the prepared fibers is closely associated with the type of electrospinning solvents. The prepared CA fibers were used as an extractive phase for on–line micro–solid phase extraction (μ-SPE) of nonsteroidal–inflammatory drugs (NSAIDs) in biological samples pursued by HPLC–UV determination. Work conducted on this research ascertained that the use of dichloromethane:acetone (3:1, v/v) solvent system in the CA dissolution for electrospinning, leads to the formation of porous ribbon–like fibers and... 

In this study, firstly, a double-reservoir and switchable prototype of a micro-chip along with the respective holders were fabricated. A cyclic desorption process using microliter volume of organic solvent was adopted to prevent any outdoor contamination. As extractive phases, two identical sheets of electrospun polyamide/polypyrrole/titania nanofibers were synthesized using core–shell electro-spinning technique and utilized for determination of memantine in plasma samples. Field emission scanning electron microscopy images showed a high degree of porosity and homogeneity throughout the sheet structure. Also, energy dispersive X-ray analysis confirmed the presence of titania, while the...