Hydroxyurea-Increased Fetal Hemoglobin Is Associated with Less Organ Damage and Longer Survival in Adults with Sickle Cell Anemia

Background

Adults with sickle cell anemia (HbSS) are inconsistently treated with hydroxyurea.

Objectives

We retrospectively evaluated the effects of elevating fetal hemoglobin with hydroxyurea on organ damage and survival in patients enrolled in our screening study between 2001 and 2010.

Methods

An electronic medical record facilitated development of a database for comparison of study parameters based on hydroxyurea exposure and dose. This study is registered with ClinicalTrials.gov, number NCT00011648.

Results

Three hundred eighty-three adults with homozygous sickle cell disease were analyzed with 59 deaths during study follow-up. Cox regression analysis revealed deceased subjects had more hepatic dysfunction (elevated alkaline phosphatase, Hazard Ratio = 1.005, 95% CI 1.003–1.006, p<0.0.0001), kidney dysfunction (elevated creatinine, Hazard Ratio = 1.13, 95% CI 1.00–1.27, p = 0.043), and cardiopulmonary dysfunction (elevated tricuspid jet velocity on echocardiogram, Hazard Ratio = 2.22, 1.23–4.02, p = 0.0082). Sixty-six percent of subjects were treated with hydroxyurea, although only 66% of those received a dose within the recommended therapeutic range. Hydroxyurea use was associated with improved survival (Hazard Ratio = 0.58, 95% CI 0.34–0.97, p = 0.040). This effect was most pronounced in those taking the recommended dose of 15–35 mg/kg/day (Hazard Ratio 0.36, 95% CI 0.17–0.73, p = 0.0050). Hydroxyurea use was not associated with changes in organ function over time. Further, subjects with higher fetal hemoglobin responses to hydroxyurea were more likely to survive (p = 0.0004). While alkaline phosphatase was lowest in patients with the best fetal hemoglobin response (95.4 versus 123.6, p = 0.0065 and 96.1 versus 113.6U/L, p = 0.041 at first and last visits, respectively), other markers of organ damage were not consistently improved over time in patients with the highest fetal hemoglobin levels.

Conclusions

Our data suggest that adults should be treated with the maximum tolerated hydroxyurea dose, ideally before organ damage occurs. Prospective studies are indicated to validate these findings.     

Haptoglobin and CCR2 receptor expression in ovarian cancer cells that were exposed to ascitic fluid: Exploring a new role of haptoglobin in the tumoral microenvironment

Haptoglobin (Hp) is an acute-phase protein that is produced by the liver to capture the iron that is present in the blood circulation, thus avoiding its accumulation in the blood. Moreover, Hp has been detected in a wide variety of tissues, in which it performs various functions. In addition, this protein is considered a potential biomarker in many diseases, such as cancer, including ovarian carcinoma; however, its participation in the cancerous processes has not yet been determined. The objective of this work was to demonstrate the expression of Hp and its receptor CCR2 in the ovarian cancer cells and its possible involvement in the process of cell migration through changes in the rearrangement of the actin cytoskeleton using western blot and wound-healing assays and confirming by confocal microscopy. Ovarian cancer cells express both Hp and its receptor CCR2 but only after exposure to ascitic fluid, inducing moderated cell migration. However, when the cells are exposed to exogenous Hp, the expression of CCR2 is induced together with drastic changes in the actin cytoskeleton rearrangement. At the same time, Hp induced cell migration in a much more efficient manner than did ascitic fluid. These effects were blocked when the CCR2 synthetic antagonist RS102895 was used to pretreat the cells. These results suggest that Hp-induced changes in the cell morphology, actin cytoskeleton structure, and migration ability of tumor cells, is possibly “preparing” these cells for the potential induction of the metastatic phenotype.     

Interface Design to Improve the Performance and Stability of Solution‐Processed Small‐Molecule Conventional Solar Cells

A systematic study on the effect of various cathode buffer layers on the performance and stability of solution‐processed small‐molecule organic solar cells (SMOSCs) based on tris{4‐[5‐(1,1‐dicyanobut‐1‐en‐2‐yl)‐2,2‐bithiophen‐5‐yl]phenyl}amine (N(Ph‐2T‐DCN‐Et)₃):6,6‐phenyl‐C71‐butyric acid methyl ester (N(Ph‐2T‐DCN‐Et)₃:PC₇₀BM) is presented. The power conversion efficiency (PCE) in these systems can be significantly improved from approximately 4% to 5.16% by inserting a metal oxide (ZnO) layer between the active layer and the Al cathode instead of an air‐sensitive Ba or Ca layer. However, the low work‐function Al cathode is susceptible to chemical oxidation in the atmosphere. Here, an amine group functionalized fullerene complex (DMAPA‐C₆₀) is inserted as a cathode buffer layer to successfully modify the interface towards ZnO/Ag and active layer/Ag functionality. For devices with ZnO/DMAPA‐C₆₀/Ag and DMAPA‐C₆₀/Ag cathodes the PCEs are improved from 2.75% to 4.31% and to 5.40%, respectively, compared to a ZnO/Ag device. Recombination mechanisms and stability aspects of devices with various cathodes are also investigated. The significant improvement in device performance and stability and the simplicity of fabrication by solution processing suggest this DMAPA‐C₆₀‐based interface as a promising and practical pathway for developing efficient, stable, and roll‐to‐roll processable SMOSCs.     

New taxonomic data on the genus Ypsolopha Latreille (Lepidoptera,Ypsolophidae) with descriptions of two new species from the Russian Far East

Two new species of the genus Ypsolopha Latreille, 1796 are described from Far East of Russia: Ypsolopha melanofuscella sp. n. and Ypsolopha straminella sp. n. Two new synomymies are proposed: Ypsolopha ulingensis Yang, 1977, a new junior synonym of Ypsolopha costibasella (Caradja, 1939); and Cerostoma falculella Erschoff, 1877, a new junior synonym of Ypsolopha asperella Linnaeus, 1761. The species Ypsolopha costibasella Caradja, 1939, Ypsolopha nigrofasciata Yang, 1977 and Ypsolopha nigrimaculata Byun et Park, 2001 are recorded from Far East of Russia for the first time. The male genitalia of Ypsolopha nigrofasciata are described and illustrated for the first time, diagnostic genital characters are given.     

Fossil insects of the middle and upper Permian of European Russia

Fossil insects of European Russia from the Urzhumian to Vyatkian stages are reviewed, new taxa are described, and dynamics of insect taxonomic diversity around the Permian-Triassic boundary in light of the Paleozoic-Mesozoic boundary global extinction problem is analyzed. Traces of interactions between arthropods and plants are analyzed. Insect-bearing deposits of the Late Paleozoic found in the northern and eastern areas of the East European Platform are unique on the global scale in their completeness and continuity, allowing us to trace especially comprehensively the biotic processes that occurred around the boundary described as the time of the greatest biotic catastrophe of the Phanerozoic. A total of 28 genera and 111 species are newly described. Within the range from the Urzhumian to the Permo-Triassic boundary, 15 representative successive assemblages, including 112 families, are recognized (seven in the area in question and eight in other regions of Asia, Australia, and Africa). New tools are developed for the analysis of the dynamics of diversity. These tools show an approximately equilibrium (slightly positive) dynamics in the Urzhumian and Severodvinian and a drop in diversity during the Vyatkian Age. It is shown that Permian insect assemblages acquired a substantially post-Paleozoic pattern much earlier than the end of the Paleozoic. The character of changes that took place in the Induan and Olenekian remains uncertain, but a large-scale extinction event did not occur here: most families that have not been recorded at the beginning of the Triassic are recorded again in the Middle and Upper Triassic. Nevertheless, a biotic crisis probably actually took place, but was reduced to reorganization of the biota’s structure, which provided enormous growth of biodiversity over subsequent hundreds of millions of years, rather than resulted in catastrophic extinction. This study is intended for entomologists, stratigraphers, and all readers interested in the biotic events that took place around the Permian-Triassic boundary.     

Selection of the peptide mass tolerance value for the protein identification with peptide mass fingerprinting

Peptide mass-fingerprint is widely used for protein identification while studying proteome with the use of 1D or 2D electrophoresis. Peptide mass tolerance indicates the fit of theoretical peptide mass with the experimental measurements, and choice of this parameter sufficiently influences the protein identification. The role of peptide mass tolerance was estimated by counting the number of identified proteins for the reference set of mass-spectra. The reference set of 400 Ultraflex (Bruker Daltonics, Germany) mass-spectra was obtained for the slices of 1D gel of liver microsomes. Using Mascot server for protein identification, the peptide mass tolerance value was varied in the range from 0.02 to 0.40 Da with a step 0.01 Da. Depending on the tolerance the number of identified protein changes up to 10 times. Maximal number of identified proteins was reported for the tolerance value of 0.15 Da (120 ppm), which is 1.5 - 2 times higher than the recommended values for such type of mass-spectrometers. The software program PMFScan was developed to obtain the dependence of number of identified proteins of the tolerance values.     

Expression of the catalytic antibodies in eukaryotic systems

Expression of recombinant antibodies in mammalian cells is one of key problems in immunobiotechnology. Alternatively, expression of a broad panel of antibodies and of their fragments may be effectively done in yeast cells. We obtained expression strains of the methylotrophic beast Pichia pastoris producing single chain human catalytic antibody A17 (A.17scFv), Fab-fragment (A.17Fab) and full-size light chain (A.17Lch). These antibodies were characterized in terms of functional activity. The capacity to specifically bind and transform organophosphorus compounds has been demonstrated for A.17scFv and A.17Fab. The loss of activity of the antibody light chain when expressed alone indicates that the active site is formed by both heavy and light chains of the antibody. We determined the reversible constant Kd and the first order constant (k2) of the reaction of the covalent modification of A.17scFv and A.17Fab by irreversible inhibitor of the serine proteases p-nitrophenyl 8-methyl-8-azobicyclo[3.2.1]phosphonate (Phosphonate X). Calculated values indicate that activity of the antibodies expressed in yeast is similar to the full-size antibody A17 and single chain antibody A.17 expressed in CHO and E. coli cells respectively.     

Specific features of the mature microrna nucleotide sequences can influence the affinity for the human Ago2 and Ago3 proteins

Mature microRNAs (miRNAs) with a length of 20–24 nucleotides are endogenous, small, non-coding RNAs. They program the RNA-induced silencing complex (RISC) to inhibit translation of the mRNAs carrying the sites complementary to these miRNAs. When the RISC contains Ago3, the mRNA translation is inhibited; however, in the case of Ago2, the mRNA can be also cleaved in the center of mRNA/miRNA heteroduplex. Using the earlier developed system ACTIVITY, we have analyzed the published data on the affinity of mature human miRNA sequences for the Ago2 and Ago3 proteins. It has been found that the higher the abundance of YRHB tetranucleotides near the miRNA 3′-end, the higher the miRNA affinity for both proteins (r = 0.613, α < 0.025) and that the miRNA binding to Ago2 increases relative to that Ago3 with the abundance of RHHK tetranucleotides near the miRNA center (r=0.501, α < 0.05). These two patterns allowed us to propose equations for predicting the affinity of mature miRNAs for the Ago2 and Ago3 proteins and to reliably predict the affinity of canonical (α < 0.00025) and noncanonical (α < 0.05) miRNAs for each protein using independent data.     

Prediction of eukaryotic mRNA translational properties.

MOTIVATION: It is well known that eukaryotic mRNAs are translated at different levels depending on their sequence characteristics. Evaluation of mRNA translatability is of importance in prediction of the gene expression pattern by computer methods and to improve the recognition of mRNAs within cloned nucleotide sequences. It may also be used in biotechnological experiments to optimize the expression of foreign genes in transgenic organisms. RESULTS: The sets of 5' untranslated region characteristics, significantly different between mRNAs encoding abundant and scarce polypeptides, were determined for mammals, dicot plants and monocot plants, and collected in the LEADER_RNA database. Computer tools for the prediction of mRNA translatability are presented. AVAILABILITY: Programs for mRNA translatability prediction are available at http://wwwmgs.bionet.nsc. ru/programs/acts2/mo_mRNA.htm (for monocots), http://wwwmgs.bionet. nsc.ru/programs/acts2/di_mRNA.htm (for dicots) and http://wwwmgs. bionet.nsc.ru/programs/acts2/ma_mRNA.htm (for mammals). The LEADER_RNA database may be accessed at: http://wwwmgs.bionet.nsc. ru/systems/LeaderRNA/.