Effect of annealing temperature and dopant concentration on the thermoluminescence sensitivity in LiF:Mg,Cu,Ag material

LiF:Mg,Cu,Ag is a new dosimetry material that is similar to LiF:Mg,Cu,P in terms of dosimetric properties. The effect of the annealing temperature in the range of 200 to 350°C on the thermoluminescence (TL) sensitivity and the glow curve structure of this material at different concentrations of silver (Ag) was investigated. It has been demonstrated that the optimum values of the annealing temperature and the Ag concentration are 240°C and 0.1 mol% for better sensitivity, respectively. The TL intensity decreases at annealing temperatures lower than 240°C or higher than 240°C, reaching a minimum at 300°C and then again increases for various Ag concentrations. It was observed that the glow curve structure altered and the area under the low temperature peak as well as the area under the main dosimetric peak decreased with increasing annealing temperature. The position of the main dosimetric peak moved in the direction of higher temperatures, but at 320 and 350°C annealing temperatures, it shifted to lower temperatures. It was also observed that the TL sensitivity could partially be recovered by a combined annealing procedure.     

Is urine a reliable clinical sample for the diagnosis of human visceral leishmaniasis? A systematic review and meta-analysis

Visualization of amastigotes in lymph nodes, bone marrow, and other tissues samples remains the gold standard method for the diagnosis of visceral leishmaniasis (VL) in humans. This gold standard diagnostic method uses a technically challenging microscopy procedure that is often not accessible in many places in the world where VL is endemic. Here, we report the current systematic review and meta-analysis to evaluate whether urine is a reliable clinical sample for diagnosis of human VL. Data were extracted from ten available databases during the period from 2002 to 2017. Overall, 29 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review. Most studies (72.4%) using urine specimens were reported from five countries: India 6 (20.7%), Iran 5 (17.2%), Bangladesh 4 (13.8%), Japan 3 (10.3%) and Spain 3 (10.3%), respectively. The most common diagnostic tests performed on urine were Katex (62.1%), ELISA (24.1%), and the rK39 (17.2%) assays. In meta-analysis the sensitivity and specificity of the three most commonly used diagnostic assays were rK39 (97%; CI: 91–99; 98%;76–100), ELISA (91%; 82–95; 99%; CI: 94–100), and Katex (83%; 73–90; 98%; 98–100), suggesting that the rK39 assay provided the highest sensitivity and the ELISA assay provided the highest specificity for diagnosis of VL from urine samples. Our findings suggest that urine is a valuable clinical sample for the diagnosis of human VL, particularly in areas where the gold standard test for VL is not available.     

17th Chromosome‐Centric Human Proteome Project Symposium in Tehran

This report describes the 17th Chromosome‐Centric Human Proteome Project which was held in Tehran, Iran, April 27 and 28, 2017. A brief summary of the symposium's talks including new technical and computational approaches for the identification of novel proteins from non‐coding genomic regions, physicochemical and biological causes of missing proteins, and the close interactions between Chromosome‐ and Biology/Disease‐driven Human Proteome Project are presented. A synopsis of decisions made on the prospective programs to maintain collaborative works, share resources and information, and establishment of a newly organized working group, the task force for missing protein analysis are discussed.     

A Novel Cell Disruption Approach: Effectiveness of Laser-induced Cell Lysis of <Emphasis Type="Italic">Pichia pastoris</Emphasis> in the Continuous System

In biotechnological processes, often cell disruption has been an inevitable step as current host cells express most of the desired products intracellularly. Thus, an appropriate cell disruption technique must be selected considering different factors including the target product, process scale, and cell wall structure. In the current study, as a novel method, the efficacy of cell disruption via laser was tested qualitatively and quantitatively in batch and continuous systems, respectively. Laser-induced cell lysis can be a clean, rapid and convenient alternative to the other conventional disruption techniques. Our investigations in the continuous system with a flow rate of 800 μL/sec proved efficient (~ 90%) Pichia pastoris cell disruption at the wavenumber 1,064 nm with the energy input of 284 mW after four complete rounds of circulation. The main mechanism of cell disruption is assumed to be thermolysis via instant heat increase in the laser-treated spot. The results of the current study showed that continuous laser system could be applied in laboratory and industry scale for cell disruption.     

Leukocyte Gene Expression and Plasma Concentration in Multiple Sclerosis: Alteration of Transforming Growth Factor-βs,Claudin-11, and Matrix Metalloproteinase-2

Multiple sclerosis is a neurodegenerative disease characterized by the present of leukocytes in the brain tissue and subsequently the formation of sclerotic plaques. Leukocytes penetration into the blood–brain barrier is related to several factors, such as, the conversion of leukocyte gene expression or plasma characteristics. In this frame, we explore alteration of matrix metalloproteinase-2 (MMP-2), transforming growth factor beta (TGF-β) family, and Claudin-11 (as a main myelin structural protein) in leukocytes and blood plasma of multiple sclerosis patients compared to the normal group. Blood samples were collected from thirteen men affected by MS and fifteen healthy men. Leukocyte gene expression was measured using real-time PCR and plasma parameters were examined by ELISA. The results of this study showed that the gene expression of Claudin-11 was significantly higher in MS group compared with normal. Interestingly, the MMP-2 pattern was similar to Claudin-11 and correlated positively with it. It was observed that, although the expressions of TGF-β1 and TGF-β2 are down-regulated in the leukocytes of subjects with MS, they showed higher levels of these cytokines in blood plasma. The plasma level of TGF-β3 in MS patients was higher than normal and correlated with Claudin-11 concentration. In conclusion, the aberrant pattern of Claudin-11, TGF-βs family, and MMP-2 expression in leukocytes of the MS patients was observed in this study. Moreover, the plasma levels of TGF-βs family increased in the MS group. The findings of this study provide clues for further investigations to assay MS pathogenesis.     

Non‐additive stabilization by halogenated amino acids reveals protein plasticity on a sub‐angstrom scale

It has been a long‐standing goal to understand the structure‐stability relationship of proteins, as optimal stability is essential for protein function and highly desirable for protein therapeutics. Halogenation has emerged as a minimally invasive strategy to probe the physical characteristics of proteins in solution, as well as enhance the structural stabilities of proteins for therapeutic applications. Although advances in synthetic chemistry and genetic code expansion have allowed for the rapid synthesis of proteins with diverse chemical sequences, much remains to be learned regarding the impact of these mutations on their structural integrity. In this contribution, we present a systematic study of three well‐folded model protein systems, in which their structural stabilities are assessed in response to various hydrogen‐to‐halogen atom mutations. Halogenation allows for the perturbation of proteins on a sub‐angstrom scale, offering unprecedented precision of protein engineering. The thermodynamic results from these model systems reveal that in certain cases, proteins can display modest steric tolerance to halogenation, yielding non‐additive consequences to protein stability. The observed sub‐angstrom sensitivity of protein stability highlights the delicate arrangement of a folded protein core structure. The stability data of various halogenated proteins presented herein should also provide guidelines for using halogenation as a strategy to improve the stability of protein therapeutics.     

Genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody in Iran

During 2010–14 surveys in the major sesame growing areas of Fars, Yazd and Isfahan provinces (Iran), genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody were studied. Virtual RFLP, phylogenetic, and DNA homology analyses of partial 16S ribosomal sequences of phytoplasma strains associated with symptomatic plants revealed the presence of phytoplasmas referable to three ribosomal subgroups, 16SrII-D, 16SrVI-A, and 16SrIX-C. The same analyses using 16S rDNA sequences from sesame phyllody-associated phytoplasmas retrieved from GenBank database showed the presence of phytoplasmas clustering with strains in the same subgroups in other Iranian provinces including Bushehr and Khorasan Razavi. Circulifer haematoceps and Orosius albicinctus, known vectors of the disease in Iran, were tested for transmission of the strains identified in this study. C. haematoceps transmitted 16SrII-D, 16SrVI-A, and 16SrIX-C phytoplasmas, while O. albicinctus only transmitted 16SrII-D strains. Based on the results of the present study and considering the reported presence of phytoplasmas belonging to the same ribosomal subgroups in other crops, sesame fields probably play an important role in the epidemiology of other diseases associated with these phytoplasmas in Iran.