Sharif Digital Repository

Background: There has been considerable interest in target immunotherapy in patients with diabetes. This study was designed to identify the effect of BCG vaccination in the treatment of Iranian patients with longstanding diabetes mellitus type 1. Methods: After approval of the cross-sectional study protocol by the ethics committee under number IRCT2017042919940N2, a total of 19 Iranian volunteers with diabetes mellitus type 1 completed this 48-month study. These patients received three 0.1 ml intradermal injections of BCG vaccination in weeks 0, 4 and 24. The serum level of glucose, HgbA1C and c-peptide was measured before and serially after the interventions. Insulin requirements were... 

Microfluidics has been becoming more and more popular over last two decades. The reason for this, is inherent features of microfluidics including low consumption of samples and reagents, high sensitivity, short analysis time, and low cost. As well as, centrifugal microfluidics as a subset of microfluidics has been able to prove itself as a helpful tool in analytic assays. The main application of centrifugal microfluidic devices is being used in point-of-care testing systems. Herein, we presented a microfluidic disc for measuring hemoglobin(Hb) concentration in the EDTA-anticoagulated venous blood using cyanmethemoglobin method. In this experiment, at first a hand-made standard solution was... 

Diabetes mellitus is a global endemic with a rapidly increasing prevalence in both developing and developed countries. Recently, hemoglobin A1c has been recommended by the American Diabetes Associations as a possible substitute for fasting blood glucose for the diagnosis of diabetes, because it is an indicator of long-term glycemic control. Also, centrifugal microfluidic systems have good potential for use in the point of care testing systems. In this study, a centrifugal microfluidic disc was designed and manufactured to measure hemoglobin A1c in whole blood using an immunoturbidimetry based method. Also, a new passive valve, named septum valve, was presented to precisely control the entry... 

The interaction of n-dodecyl trimethylammonium bromide (DTAB) with oxyhemoglobin A and oxyhemoglobin S is investigated using UV-visible absorption spectra and chemometric resolution techniques. Oxyhemoglobins (A and S) induced to partial oxidized form (ferrihemoglobin) by DTAB and finally transform to fully oxidized hemichrome. Hemichrome mole fractions of HbS are more than HbA because of more hydrophobic interaction of DTAB-HbS in second set of binding site relative to DTAB-HbA. The visible spectra between 500 and 650 nm are used for identifying the present components in solution because each species of hemoglobin has a specific spectrum in this region. The number of components and mole... 

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... 

Blood oxygenation is the main performance characteristic of capillary membrane oxygenators (CMOs). Handling of natural blood in in vitro investigations of CMOs is quite complex and time-consuming. Since the conventional blood analog fluids (e.g. water/glycerol) lack a substance with an affinity to capture oxygen comparable to hemoglobin's affinity, in this study a novel approach using modified sulfite solution is proposed to address this challenge. The solution comprises sodium sulfite as a component, simulating the role of hemoglobin in blood oxygenation. This approach is validated by OTR (oxygen transfer rate) measured using native porcine blood, in two types of commercially available... 

As the delay time and hence nuclei formation play a crucial role in the pathophysiology of sickle cell disease, MD simulation and molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) calculations have been performed on three systems of hemoglobin; namely dimer of hemoglobin with valine (Hb S), tryptophan (Hbβ6W), and phenylalanine (Hbβ6F) at β6 position. The structural changes due to these aromatic substitutions are investigated. It is shown that β subunits have significant impact on the differences between a dimer and other crystal structures. Transition from a dimer to polymer for Hb S system affects the donor molecule more than that of the acceptor. In the case of donor and... 

This study proposes a mathematical model to evaluate the impact of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a 3D cardiac construct using computational fluid dynamics (CFD). Flow equations, oxygen balance equation and cell balance equation were solved using special initial and boundary conditions. The modeling results revealed that 55% increase in cardiac cell density occurred by using 6.4% perfluorocarbon oxygen carrier (PFC) compared to pure culture medium without PFC supplementation. Moreover, the effects of the scaffold geometry on cell density were examined by changing the channel numbers and the construct length. A 30% increase in the average cells... 

Mononuclear nonheme iron containing systems are versatile and vital oxidants of substrate hydroxylation reactions in many biosystems, whereby the rate constant of hydroxylation correlates with the strength of the C-H bond that is broken in the process. The thermodynamic reason behind these correlations, however, has never been established. In this work results of a series of density functional theory calculations of substrate hydroxylation by a mononuclear nonheme iron(IV)-oxo oxidant with a 2 His/ 1Asp structural motif analogous to aketoglutarate dependent dioxygenases are presented. The calculations show that these oxidants are very efficient and able to hydroxylate strong C-H bonds,... 

Metal–organic frameworks (MOFs) have been widely used as porous nanomaterials for different applications ranging from industrial to biomedicals. An unpredictable one-pot method is introduced to synthesize NH2-MIL-53 assisted by high-gravity in a greener media for the first time. Then, porphyrins were deployed to adorn the surface of MOF to increase the sensitivity of the prepared nanocomposite to the genetic materials and in-situ cellular protein structures. The hydrogen bond formation between genetic domains and the porphyrin’ nitrogen as well as the surface hydroxyl groups is equally probable and could be considered a milestone in chemical physics and physical chemistry for biomedical... 

Fluid particle diffusion through blood flow within a capillary tube is an important phenomenon to understand, especially for studies in mass transport in the microcirculation as well as in solving technical issues involved in mixing in biomedical microdevices. In this paper, the spreading of tracer particles through up to 20% hematocrit blood, flowing in a capillary tube, was studied using a confocal micro-PTV system. We tracked hundreds of particles in high-hematocrit blood and measured the radial dispersion coefficient. Results yielded significant enhancement of the particle diffusion, due to a micron-scale flow-field generated by red blood cell motions. By increasing the flow rate, the... 

Introduction: This study was conducted to investigate the relationship of glomerular and tubular dysfunctions with glycaemic control, lipid, lipoprotein, apolipoproteins and antioxidant status in 72 patients with type 2 diabetes mellitus. Methods: Urine albumin concentration was measured by immunoturbidimetric and urine N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) activities with colorimetric methods. Glycated haemoglobin was measured using affinity chromatography. Erythrocyte glu ta thione reductase and glutathione peroxidase activities and serum levels of malondialdehyde, lipids, lipoproteins and apolipoproteins were determined in patients with type 2 diabetes... 

The catalytic activity of highvalent iron-oxo active species of heme enzymes is known to be dependent on the nature of the axial ligand trans to the iron-oxo group. In a similar fashion, experimental studies on iron-oxo porphyrin biomimetic systems have shown a significant axial ligand effect on ethylbenzene hydroxylation, with an axial acetonitrile ligand leading to phenyl hydroxylation products and an axial chloride anion giving predominantly benzyl hydroxylation products. To elucidate the fundamental factors that distinguish this regioselectivity reversal in iron-oxo porphyrin catalysis, we have performed a series of density functional theory calculations on the hydroxylation of...