bluuebunny/crossref_metadata_2025 huggingface dataset:
Perilipin-related protein regulates lipid metabolism in C. elegans
Authors: Chughtai Ahmed A. , Kaššák Filip , Kostrouchová Markéta , Novotný Jan Philipp , Krause Michael W. , Saudek Vladimír , Kostrouch Zdenek , Kostrouchová Marta
Published: January 2018

The perilipins are lipid droplet surface proteins that contribute to fat metabolism by controlling the access of lipids to lipolytic enzymes. Perilipins have been identified in organisms as diverse as metazoa, fungi, and amoebas but strikingly not in nematodes. Here we identify the protein encoded by the W01A8.1 gene in Caenorhabditis elegans as the closest homologue of metazoan perilipin. We demonstrate that nematode W01A8.1 is a cytoplasmic protein residing on lipid droplets. Human perilipins 1 and 2 localize in transgenic C. elegans on the same structures as proteins expressed from W01A8.1 gene. Inhibition and elimination of W01A8.1 affects the appearance of lipid droplets especially visible as the formation of large lipid droplets localized around the dividing nucleus during the early zygotic divisions. This phenomenon disappears in later stages of embryogenesis indicating the existence of an additional mechanism of lipid regulation in C. elegans. Our results demonstrate that perilipin-related regulation of fat metabolism is conserved in nematodes and provide new possibilities for functional studies of lipid metabolism.
Mechanistic pathways of mercury removal from the organomercurial lyase active site
Authors: Silva Pedro J , Rodrigues Viviana
Published: January 2018

Bacterial populations present in Hg-rich environments have evolved biological mechanisms to detoxify methylmercury and other organometallic mercury compounds. The most common resistance mechanism relies on the H+-assisted cleavage of the Hg-C bond of methylmercury by the organomercurial lyase MerB. Although the initial reaction steps which lead to the loss of methane from methylmercury have already been studied experimentally and computationally, the reaction steps leading to the removal of Hg2+ from MerB and regeneration of the active site for a new round of catalysis have not yet been elucidated. In this paper, we describe an MP2/CBS//B3PW91/6-31G(d) study of the final steps of the reaction catalyzed by MerB. While conceptually simple, these reaction steps occur in a complex potential energy surface where several distinct pathways are accessible and may operate concurrently. The only pathway which clearly emerges as forbidden in our analysis is the one arising from the sequential addition of two thiolates to the metal atom, due to the accumulation of negative charges in the active site. Addition of two thiols, in contrast, leads to two feasible mechanistic possibilities. The most straightforward pathway proceeds through proton transfer from the attacking thiol to Cys159 , leading to its removal from the mercury coordination sphere, followed by a slower attack of a second thiol, which removes Cys96. The other pathway involves Asp99 in an accessory role similar to the one observed earlier for the initial stages of the reaction and affords a lower activation enthalpy, around 14 kcal.mol-1, determined solely by the cysteine removal step rather than by the thiol ligation step. Addition of one thiolate to the intermediates arising from either thiol attack occurs without a barrier and produces an intermediate bound to one active site cysteine and from which Hg(SCH3)2 may be removed only after protonation by solvent-provided H3O+. Thiolate addition to the active site (prior to any attack by thiols) leads to pathways where the removal of the first cysteine becomes the rate-determining step, irrespective of whether Cys159 or Cys96 leaves first. Comparisons with the recently computed mechanism of the related enzyme MerA further underline the important role of Asp99 in the energetics of the MerB reaction.
Integrating bioinformatics tools to investigate protein phosphorylation
Authors: Vlachakis Dimitrios , Bencurova Elena , Bhide Mangesh , Kossida Sophia
Published: January 2018

Protein phosphorylation is one of the most important protein post-translational modifications and plays a role in numerous cellular processes including recognition, signaling and degradation. It can be studied experimentally by various methodologies, like employing western blot analysis, site-directed mutagenesis, 2 D gel electrophoresis, mass spectrometry etc. A number of in silico tools have also been developed in order to predict plausible phosphorylation sites in a given protein. In this review, we conducted a benchmark study including the leading protein phosphorylation prediction software, in an effort to determine which performs best. The first place was taken by GPS 2.2, having predicted all phosphorylation sites with a 83% fidelity while in second place came NetPhos 2.0 with 69%.
Positive catch and economic benefits of periodic octopus fishery closures: do effective, narrowly targeted actions ‘catalyze’ broader management?
Authors: Oliver Thomas , Oleson Kirsten LL , Ratsimbazafy Hajanaina H.A.R , Raberinary Daniel , Benbow Sophie , Harris Alasdair
Published: January 2018

Eight years of octopus fishery records from southwest Madagascar reveal significant positive impacts from 36 periodic closures on: (a) fishery catches and (b) village fishery income, such that (c) economic benefits from increased landings outweigh costs of foregone catch. Closures covered ~20% of a village’s fished area and lasted 2-7 months. Fishery catches from each closed site: Octopus landings and catch per unit effort (CPUE) significantly increased in the 30 days following a closure’s reopening, relative to the 30 days before a closure (landings: +718%, p<0.0001; CPUE: +87%, p<0.0001; n=36). Open-access control sites showed no before/after change when they occurred independently of other management (“no ban”, n=17/36). On the other hand, open-access control sites showed modest catch increases when they extended a 6-week seasonal fishery shutdown (“ban”, n=19/36). The seasonal fishery shutdown affects the entire region, so confound all potential control sites. Fishery income in implementing villages: In villages implementing a closure, octopus fishery income doubled in the 30 days after a closure, relative to 30 days before (+132%, p<0.001, n=28). Control villages not implementing a closure showed no increase in income after “no ban” closures and modest increases after “ban” closures. Villages did not show a significant decline in income during closure events. Net economic benefits from each closed site: Landings in closure sites generated more revenue than simulated landings assuming continued open-access fishing at that site (27/36 show positive net earnings; mean +$305/closure; mean +57.7% monthly). Benefits accrued faster than local fishers’ time preferences during 17-27 of the 36 closures. High reported rates of illegal fishing during closures correlated with poor economic performance. We discuss the implications of our findings for broader co-management arrangements, particularly for catalyzing more comprehensive management.
A standardized, extensible framework for optimizing classification improves marker-gene taxonomic assignments
Authors: Bokulich Nicholas A , Rideout Jai Ram , Kopylova Evguenia , Bolyen Evan , Patnode Jessica , Ellett Zach , McDonald Daniel , Wolfe Benjamin , Maurice Corinne F , Dutton Rachel J , Turnbaugh Peter J , Knight Rob , Caporaso J Gregory
Published: January 2018

Background: Taxonomic classification of marker-gene (i.e., amplicon) sequences represents an important step for molecular identification of microorganisms.

Results: We present three advances in our ability to assign and interpret taxonomic classifications of short marker gene sequences: two new methods for taxonomy assignment, which reduce runtime up to two-fold and achieve high precision genus-level assignments; an evaluation of classification methods that highlights differences in performance with different marker genes and at different levels of taxonomic resolution; and an extensible framework for evaluating and optimizing new classification methods, which we hope will serve as a model for standardized and reproducible bioinformatics methods evaluations.

Conclusions: Our new methods are accessible in QIIME 1.9.0, and our evaluation framework will support ongoing optimization of classification methods to complement rapidly evolving short-amplicon sequencing and bioinformatics technologies. Static versions of all of the analysis notebooks generated with this framework, which contain all code and analysis results, can be viewed at http://bit.ly/srta-010.
Physical inactivity: results from a pilot study with Mexican youth using mobile accelerometry
Authors: Saldívar Jimena , Gómez Pedro , Daumer Martin
Published: January 2018

The obesity epidemic is a worldwide problem. Studies from the late 20th century show a consistent trend of increasing obesity prevalence on a global scale (Popkin & Doak, 1998). The OECD reports that overweight and obese people are now a majority amongst OECD countries, with Mexico having one of the highest obesity rates: as of 2012, 32.4% of the adult population was obese (Wilson, Devaux, & Cecchini, 2014). Obesity, in turn, is a risk factor to many of the most widespread chronic diseases: diabetes, cardiovascular diseases, and even cancer. We propose that a preventive strategy towards obesity will result in long-term and high impact results. Our strategy focuses on changing two significant lifestyle factors: diet and physical activity. The former is achieved by a comprehensive health education and habit-forming program; the latter, by personalized goal setting based on activity measurements with the use of mobile accelerometry. This work presents the physical activity results of a pilot study realized with Mexican youth. Within this study, we explore the use of the motivational package “Move-your-health®” alongside a series of workshops to validate the hypothesis that personalized goal setting leads to a measurable increase in physical activity.
How sex acts scale with the number of sex partners: evidence from Chlamydia trachomatis data and implications for control
Authors: Althaus Christian L , Choisy Marc , Alizon Samuel ,   the CSF group
Published: January 2018

Mathematical models are frequently used to assess the impact of control interventions for Chlamydia trachomatis and other sexually transmitted infections (STIs). Modeling approaches that stratify the population by the number of sex partners often assume the transmission risk per partner to be constant. However, sexual behavior data suggests that people with many partners share less sex acts per partner than people with fewer partners. This should lower the risk of transmission per partner for highly sexually active individuals and could have important epidemiological consequences for STI transmission. We devise a new epidemiological model that we fit to chlamydia prevalence data from Natsal-2 and CSF, two population-based probability sample surveys of sexual behavior in Britain and France. Compared to a standard model where the transmission risk per partner is constant, a model with realistic numbers of sex acts per partner provides a better fit to the data. Furthermore, the improved model provides evidence for strong assortative mixing among individuals with different numbers of sex partners. Our results suggest that all chlamydia infected individuals with one or more new heterosexual partners per year contribute significantly to ongoing transmission, underlining that control interventions should be aimed towards all sexually active young adults.
Electrical induction hypothesis to explain enhancer-promoter communication
Authors: Agoni Valentina
Published: January 2018

The steps of the DNA replication process remains to be clarified. Transcription factors are supposed to find their specific binding-sequence driven by epigenetic modifications and GpC islands. But then how can the replication machinery be able to find the promoters of exactly the genes that the cell needs to transcribe in that moment? Here we hypothesize a role of DNA conductance and electrical induction to give an explanation to this unsolved problem. Our hypothesis goes in accordance with the fact that many authors identified 3D loops in the genomes.
Living in each other’s pockets: Nucleotide variation inside a genomic island harboring Pan I and its neighbors in Atlantic cod
Authors: Benitez Hernandez Ubaldo , Árnason Einar
Published: January 2018

The Pan I locus in Atlantic cod lies in a genomic island of divergence extending over a large genomic region. The locus has two divergent alleles, defined by a single DraI restriction site, that have been related to behavioral differences of habitat selection by depth and temperature. The Pan I locus is known to be under an unusual mix of balancing selection and selective sweeps within the functional types. Here we study nucleotide variation in a 12.5 kb region inside the genomic island harboring Pan I and neighboring loci for sortilin 1 (Sort1) and ataxin 7-like 2 (Atxn7l2) which we partially covered. Variation of the 31 gene copies throughout the region falls into two divergent haplogroups that correlate with the 25 copies of A and six copies of B alleles of Pan I. The unfolded site frequency spectrum for the part with Pacific cod used as the outgroup is trimodal with a mode at singletons and two high frequency modes at 6/31 and 25/31 representing the two genealogical lineages. The folded site frequency spectrum for the entire region similarly has a high frequency mode of mutations that have accumulated on the two lineages. The high frequency of singletons is accounted for by multiple merger coalescent models. Parameter estimates using these models indicate sweepstakes reproduction. The high frequency modes of the spectrum is evidence for balancing selection. Analysis of non-synonymous changes shows that Pan I is at least one focus of selection within the genomic island. There may be multiple sites of selection and epistatic interactions. There is extensive linkage disequilibrium throughout the region. We suggest that the genomic island of divergence is a supergene of co-adapted complexes possibly locked together by structural variation.
Calcium affinity of human α-actinin1
Authors: Backman Lars
Published: January 2018

Due to alternative splicing the human ACTN1 gene codes for three different transcripts of α‑actinin; one isoform that is expressed only in the brain and two with a more general expression pattern. The sequence difference is located to the C-terminal domains and the EF-hand motifs. Therefore any functional or structural distinction should involve this part of the protein. To investigate this further, the calcium affinities of these three isoforms of α‑actinin1 have been determined by isothermal calorimetry.
Data management aspects of public engagement with biodiversity documentation
Authors: Ortiz-Troncoso Alvaro
Published: January 2018

Technological developments open up new opportunities for collaboration between biodiversity researchers and the general public. Three exemplary case studies were reviewed from literature: digitizing museum specimens, text-mining archived expedition journals and handling environmental monitoring data. Data management principles were applied to refine the ensuing requirements. Specific requirements were found to exist in three areas: collecting data, sharing data and improving data quality. Implications for data governance and quality control are discussed.
Testing Earthquake Links in Mexico From 1978 to the 2017M = 8.1 Chiapas andM = 7.1 Puebla Shocks
Authors: Segou Margarita , Parsons Tom
Published: January 2018

TheM = 8.1 Chiapas and theM = 7.1 Puebla earthquakes occurred in the bending part of the subducting Cocos plate 11 days and ~600 km apart, a range that puts them well outside the typical aftershock zone. We find this to be a relatively common occurrence in Mexico, with 14% ofM > 7.0 earthquakes since 1900 striking more than 300 km apart and within a 2 week interval, not different from a randomized catalog. We calculate the triggering potential caused by crustal stress redistribution from large subduction earthquakes over the last 40 years. There is no evidence that static stress transfer or dynamic triggering from the 8 September Chiapas earthquake promoted the 19 September earthquake. Both recent earthquakes were promoted by past thrust events instead, including delayed afterslip from the 2012M = 7.5 Oaxaca earthquake. A repeated pattern of shallow thrust events promoting deep intraslab earthquakes is observed over the past 40 years.
Data Buildings: Sensor Feedback in Sustainable Design Workflows
Authors: Peters Terri
Published: January 2018

While ever more architects use digital simulations of energy and daylight to inform their designs, relatively few carry out post‐occupancy evaluations of their buildings. This, according to University of Toronto post‐doctoral researcher Terri Peters, is a missed opportunity. Presenting recent built examples of a variety of building types by three leading practices in the US and Denmark, she sets out how sensor‐derived feedback can not only assist future design decisions in terms of building performance, operating systems and use patterns, but also encourage more sustainable behaviour among building users.
Innovativer Mehrfachprüfstand zur zyklischen Beanspruchung großformatiger Betonprobekörper
Authors: Przondziono Robin , Schulte‐Schrepping Christoph , Breitenbücher Rolf
Published: January 2018

In Betonbauwerken können zyklische Belastungen bereits lange vor einem Ermüdungsversagen zu Degradationserscheinungen im Mikrogefüge führen. In Kombination mit anderen Einwirkungen, z. B. alkalihaltige Taumittel oder Meerwasser, kann dadurch die Dauerhaftigkeit beeinträchtigt werden. Bei den zyklischen Belastungen ist zwischen lastabhängigen und lastunabhängigen zu unterscheiden. Lastunabhängige wiederkehrende Beanspruchungen stellen sich insbesondere durch thermische, in Sonderfällen auch durch hygrische Verformungen im Jahres‐ und Tagesgang ein. Lastabhängige zyklische Beanspruchungen können unterschiedlicher Natur sein, z. B. infolge Verkehr auf Fahrbahnen oder Brücken oder bei Windkraftanlagen infolge der Rotorblätter. Um den Einfluss der zyklischen Belastungen auf die Degradation und in Folge auf die Dauerhaftigkeit zeitraffend erfassen zu können, wurde am Lehrstuhl für Baustofftechnik der Ruhr‐Universität Bochum ein Mehrfachprüfstand für solche Beanspruchungen entwickelt. Dieser Prüfstand erlaubt eine praxisnahe Simulation zyklischer Lasten an großformatigen Betonkörpern. Die Entwicklung, das Funktionsprinzip sowie der erfolgreiche Einsatz des Mehrfachprüfstandes in mehreren Forschungsvorhaben werden in dieser Veröffentlichung dargestellt.
Changes in Chromosome Counts and Patterns in CHO Cell Lines upon Generation of Recombinant Cell Lines and Subcloning
Authors: Vcelar Sabine , Melcher Michael , Auer Norbert , Hrdina Astrid , Puklowski Anja , Leisch Friedrich , Jadhav Vaibhav , Wenger Till , Baumann Martina , Borth Nicole
Published: January 2018

Chinese hamster ovary (CHO) cells are the number one production system for therapeutic proteins. A pre‐requirement for their use in industrial production of biopharmaceuticals is to be clonal, thus originating from a single cell in order to be phenotypically and genomically identical. In the present study it was evaluated whether standard procedures, such as the generation of a recombinant cell line in combination with selection for a specific and stable phenotype (expression of the recombinant product) or subcloning have any impact on karyotype stability or homogeneity in CHO cells. Analyses used were the distribution of chromosome counts per cell as well as chromosome painting to identify specific karyotype patterns within a population. Results indicate that subclones both of the host and the recombinant cell line are of comparable heterogeneity and (in)stability as the original pool. In contrast, the rigorous selection for a stably expressing phenotype generated cell lines with fewer variation and more stable karyotypes, both at the level of the sorted pool and derivative subclones. We conclude that the process of subcloning itself does not contribute to an improved karyotypic homogeneity of a population, while the selection for a specific cell property inherently can provide evolutionary pressure that may lead to improved chromosomal stability as well as to a more homogenous population.
Size and Optically Tunable Ethyl Cellulose Nanoparticles as Carriers for Organic UV Filters
Authors: Hayden Douglas R. , Kibbelaar Heleen V. M. , Imhof Arnout , Velikov Krassimir P.
Published: January 2018

Optically active nanoparticles (NPs) are potential building blocks for bottom‐up functional technology in applications such as displays, sensors, and sunscreens. For sunscreens in particular, NPs can be used as delivery systems for organic UV filters in order to minimise skin exposure to these molecules. Here, we investigate the synthesis of size‐tunable ethyl cellulose NPs (ECNPs) and their application as carriers for multiple organic UV filters. We prepared ECNPs with sizes of 50 to 165 nm via an antisolvent precipitation technique and investigate the incorporation of three commonplace organic UV filters – oxybenzone, avobenzone, and octinoxate – into the ECNPs. We found the particle loading varied greatly with each UV filter. Photodegradation of the UV filters remained unchanged upon incorporation into ECNPs and was not affected by co‐encapsulating the antioxidant α‐tocopherol. These results can significantly advance the development of environmentally friendly functionalized nanoparticles and UV‐protective coatings.
Methanol–Water Aqueous‐Phase Reforming with the Assistance of Dehydrogenases at Near‐Room Temperature
Authors: Shen Yangbin , Zhan Yulu , Li Shuping , Ning Fandi , Du Ying , Huang Yunjie , He Ting , Zhou Xiaochun
Published: January 2018

As an excellent hydrogen‐storage medium, methanol has many advantages, such as high hydrogen content (12.6 wt %), low cost, and availability from biomass or photocatalysis. However, conventional methanol–water reforming usually proceeds at high temperatures. In this research, we successfully designed a new effective strategy to generate hydrogen from methanol at near‐room temperature. The strategy involved two main processes: CH3OH→HCOOH→H2 and NADH→HCOOH→H2. The first process (CH3OH→HCOOH→H2) was performed by an alcohol dehydrogenase (ADH), an aldehyde dehydrogenase (ALDH), and an Ir catalyst. The second procedure (NADH→HCOOH→H2) was performed by formate dehydrogenase (FDH) and the Ir catalyst. The Ir catalyst used was a previously reported polymer complex catalyst [Cp*IrCl2(ppy); Cp*=pentamethylcyclopentadienyl, ppy=polypyrrole] with high catalytic activity for the decomposition of formic acid at room temperature and is compatible with enzymes, coenzymes, and poisoning chemicals. Our results revealed that the optimum hydrogen generation rate could reach up to 17.8 μmol h−1 gcat−1 under weak basic conditions at 30 °C. This will have high impact on hydrogen storage, production, and applications and should also provide new inspiration for hydrogen generation from methanol.
Voltammetric Detection of Catecholamine Metabolites Using Tröger's Base Modified Electrode
Authors: Shishkanova Tatiana V. , Broncová Gabriela , Fitl Přemysl , Král Vladimír , Barek Jiří
Published: January 2018

The advantage of surface modification of voltammetric sensor for determination of catecholamine metabolites such as vanillyl mandelic acid (VMA) and homovanillic acid (HVA) is discussed. The amino‐substituted coumarin derivative of Tröger's base was deposi‐ted on a graphite screen‐printed electrode (poly(CTB)/G/SPE) cycling the electrode potential between 0 and 1.2 V in 5 mL CH2Cl2 containing 1×10−3 mol L−1 tetrabutylammonium tetrafluoroborate and 20 μL 0.1 mol L−1 HCl. The poly(CTB) functions as both a selective recognition and pre‐concentrator agent for catecholamine metabolites. The high sensitivity of the voltammetric sensor coated by a poly(CTB) film toward VMA was achieved despite the high structural similarity between the two tested metabolites. We presume the voltammetric detection of these species is based on selective binding by a poly(CTB) film supported by its good adherence to the electrode substrate. The voltammetric signals of VMA were observable in the concentration range 10–100 μmol L−1 (LOD=0.2 μmol L−1) and 20–60 μmol L−1 (LOD=10 μmol L−1) in the model and synthethic urine samples, respectively.
Posttraumatic Growth in Individuals With Chronic Illness: The Role of Social Support and Meaning Making
Authors: Zeligman Melissa , Varney Melanie , Grad Ramona I. , Huffstead Mary
Published: January 2018

This study aimed to assess the predictive nature of social support, meaning making (presence of meaning and search for meaning), and demographic factors on perceived posttraumatic growth (PTG) in a sample of adults living with chronic illness (N = 110). Regression analyses indicated that presence of meaning and gender served as the strongest predictors, together accounting for 22% of the variance in PTG. Presence of meaning also moderated the relationship between social support and PTG, supporting the unique contribution of meaning making on PTG.
Inhibition of Yeast Phagocytosis in Macrophage Cultures Treated With Slime Polysaccharide Purified From Pseudomonas aeruginosa
Authors: Grasso Robert J , Ganguly Rama , Breen John F
Published: January 2018

This study was initiated to determine whether purified slime polysacchar- ide(PSP) from P aeruginosa inhibits the ingestion of heat killed Saccharomyces cerevisiae particles in macrophage cultures. Relative to controls, direct phagocytosis assays revealed that the percentages of phagocytes and the numbers of ingested yeast particles per phagocyte decreased in a dose-dependent manner in PSP-treated cultures. Thus, PSP may act as a virulence factor in vivo by impairing the phagocytic capacity of macrophages.
The Effects of Hypothermia on Neutrophil Function In Vitro
Authors: Akriotis V , Biggar W D
Published: January 2018

Hypothermia may be associated with compromised host defenses and serious bacterial infections in man. We have examined the effects of moderate hypothermia (29°C) on neutrophil function in vitro. At 29°C, neutrophil phagocytosis of Staphylococcus aureus was impaired. In contrast, neutrophil killing of Streptococcus faecalis was most affected by hypothermia. Phagocytosis, as measured by neutrophil ingestion of opsonized oil-red-O-particles, was reduced at 29°C over the 15 min of observation. Neutrophil metabolism linked to bactericidal pathways dependent on oxidative metabolism was reduced at 29°C. Hexose monophosphate pathway (HMP) activity in neutrophils early after stimulation with latex particles was reduced. After 2 hr HMP activity was similar at 29°C and 37°C. Neotetrazolium dye reduction was reduced early after latex stimulation of neutrophils and after 30 min it was similar to cells at 37°C. Leukocyte migration under agarose to bacterial-derived and formyl-methionyl- phenylalanine chemotactic factors was reduced by 50% and 70%, respectively. Migration to serum-derived chemotactic factor was reduced by only 20%. When cells were cooled to 29°C for 30 to 90 min and rewarmed, neutrophil function was normal. These effects of hypothermia on neutrophil function may explain, in part, the increased incidence of serious and frequently fatal bacterial infections in man.
Expression of 5′Nucleotidase Activity and Wheat-Germ Agglutinin Binding Sites in Mononuclear Phagocytes From Bone Marrow Cultures
Authors: de Water R , van der Meer J W M , van't Noordende J M , Onderwater J J M , van de Gevel J S , Ginsel L A
Published: January 2018

The question as to whether the various types of mononuclear phagocyte found in bone marrow cultures and recognized by specific peroxidatic (PO) activity patterns differ in the expression of binding sites for the lectin wheat-germ agglutinin (WGA) and the activity of the ectoenzyme 5′nucleotidase (5′N) was investigated. Monoblasts, promonocytes, monocytes, and/or exudate macrophages, and exudate-resident macrophages generally showed a high level of WGA binding, and a considerably lower level was found in the PO-negative cells and in resident macrophages. 5′N activity was absent in monoblasts, promonocytes, and in the great majority of the monocytes and/or exudate macrophages, but was demonstrable in exudate-resident macrophages and resident macrophages, as well as in PO-negative macrophages after 4 days of culture. On the basis of the successive occurrence of the above-mentioned phenotypes in cultures, the possibility that this diversity in WGA binding and 5′N activity is related to modulation during cell differentiation is discussed. The present findings led to the conclusion that the PO-negative macrophages, whose origin was previously not entirely certain, are precursors of resident macrophages.
Interferon Production in Murine Macrophage-Like Cell Lines
Authors: Salo Richard J , Bleam Diana K , Greer Veronica L , Ortega Andrew P
Published: January 2018

Five murine macrophage (MΦ)-like cell lines were examined to determine their suitability for the characterization of MΦ interferons (IFNs). The J774A.1, RAW 309 Cr.1, and RAW 264.7 cell lines produced 30–800 international units (IU)/ 106 cells when treated with 5–200 μg of bacterial lipopolysaccharide (LPS). No IFN was detected in LPS-treated P388D1 or PU5-1.8 cell cultures. All cell lines produced IFN when inoculated with Newcastle disease virus (NDV); however, only 15 IU/106 cells of acid stable IFN were produced in PU5-1.8 cell cultures in comparison to 4.2 × 103-1.7 × 104 IU/106 cells in the other cell lines. Most of the IFN was produced within 4 h in LPS-treated cell cultures and within 12 h in NDV-infected cell cultures. All IFNs were stable at pH 2.0 and were neutralized with antiserum against mouse L cell IFN. These cell lines appear competent for use in studying the synthesis, molecular weights, and regulatory functions of MΦ IFNs.
Human Leukemic Models of Myelomonocytic Development: A Review of the HL-60 and U937 Cell Lines
Authors: Harris Paul , Ralph Peter
Published: January 2018

The human leukemic myeloblast HL-60 and monoblast U937 cell lines have made important contributions to the disciplines of cancer, hematology, and immunology. As sources of leukemic cells, they have been used for the study of neoplasia and therapeutics. As sources of hemic cells, they have been used for biochemical and biological analysis of regulation and differentiation in myelopoiesis. When stimulated with immunomodulatory factors, the cell lines develop properties of host-defense effector cells. They are also a source of cytokines that affect other cell types.
Induction of Macrophage Growth by the Lipid Moiety of Lipoprotein and Its Augmentation by Denaturation of the Lipoproteins
Authors: Yui Satoru , Mizuno Den'ichi , Yamazaki Masatoshi
Published: January 2018

Lipoprotein (d < 1.21) isolated from mouse tumor ascitic fluid or mouse-serum induced growth of peritoneal macrophages in vitro. Lipoprotein fractions that stimulated macrophage growth were the chylomicron, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL), whereas the high-density lipoprotein (HDL) fraction did not. Lipids extracted from total lipoprotein also showed significant macrophage-growth-stimulating activity and lost this activity when hydrolyzed. The macrophage-growth-stimulating activity of the lipoprotein (d < 1.21) was increased about ten times by heat treatment of the lipoprotein (100 °, 30 min). The HDL fraction that had no activity in the native form also showed activity after heat treatment. Lipoprotein-depleted ascitic fluid and simple proteins such as bovine serum albumin (BSA) had no activity even after heat treatment. These results show that the lipid moiety of lipoproteins caused proliferation of macrophages and that denatured lipoproteins were more effective than native ones.
Enhanced Interleukin-1 Production by Human Monocyte Cell Lines Following Treatment With 5-Azacytidine
Authors: Kovacs Elizabeth J , Oppenheim Joost J , Carter Donald B , Young Howard A
Published: January 2018

Recent studies suggest that DNA modification, such as methylation of specific bases or substitution of altered bases, can play an important role in the control of eukaryotic gene expression. We chose to examine the effects of two DNA modifying agents, 5-azacytidine (AZA) and 5-bromodeoxyuridine (BUdR), on interleukin-1 (IL-1) gene expression in the human monocyte cell lines THP-1 and U937.1. THP-1 produced IL-1 upon stimulation with lipopolysaccharide (LPS), whereas U937.1 did not. Following treatment with AZA, U937.1 cells could be induced to produce IL-1 β mRNA and release IL-1, but only if a stimulus such as LPS was present. In addition, the level of IL-1 β mRNA produced and IL-1 released by THP-1 cells after induction could be doubled by treatment with AZA. In contrast, we were unable to alter IL-1 production by treatment of cells with BUdR in the absence or presence of inducers. These results suggest that the production of IL-1 may be, in part, regulated by methylation of DNA.
Partial Purification and Characterization of Formylpeptide Receptor From Rabbit Peritoneal Neutrophils
Authors: Huang Chi-Kuang
Published: January 2018

The formylpeptide receptors from 40 × 109 cells of rabbit peritoneal neutrophils have been solubilized with digitonin and partially purified by sequential fMet-Leu-Phe-Sepharose affinity and wheat-germ agglutinin agarose affinity chromatography. The binding activity of the receptor toward [3H]fNle-Leu-Phe is difficult to restore fully after elution of the receptor from the fMet-Leu-Phe-Sepharose affinity column. A 2,000-fold purification of the receptor from the particulate fraction is achieved with a yield of about 23%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Coomasie blue or silver staining of purified receptor preparations reveal a major polypeptide with an apparent Mr (50,000-70,000) and isoelectric points (pi 6.0 - 6.5) that coincides with the polypeptide labeled by the specific affinity cross-linking probe for formylpeptide receptor (125I-hexapeptide). The receptor has an apparent Stokes radius of 47 å when analyzed by gel filtration chromatography. Using synthetic peptides poly(Glu-Tyr) (4:1) as the substrates, a membrane-associated tyrosine protein kinase activity is detected and can be solubilized by digitonin. Subsequent analysis indicates that the tyrosine kinase activity is not derived from the receptor.
Complement Component C3 Secretion by Mouse Macrophage-Like Cell Lines
Authors: Goodrum Kenneth J
Published: January 2018

Secretion of complement component C3 by the mouse macrophage-like cell lines PU5-1.8, J774A.1, RAW264.7, and P388D1 was measured using an enzyme-linked immunosorbent assay for mouse C3. All cell lines secreted antigenically detectable C3 with the relative secreted C3/106 cells/24 h ranked as J774A.1 > P388D1 PU5-1.8 > > RAW264.7.

C3 secretion was enhanced two- to fourfold in cultures of all cell lines when treated with lipopolysaccharide, streptococcal cell walls, or lymphokine-containing supernatant fluids of mitogen-stimulated spleen cells. A differential induction of C3 synthesis and secretion was indicated since secreted lysozyme and total cellular protein were not elevated in a manner comparable to C3. The relative inducibility of cell lines for C3 secretion in either lipopolysaccharide- or cell wall-treated cells could be ranked as PU5-1.8 > P388D1 > J774A.1 > RAW264.7. C3 secretion was inhibited by cycloheximide or hydrocortisone. Mouse macrophage-like cell lines retain baseline and inducible C3 synthetic activities as do normal macrophages and can serve as homogeneous cultures in which to study regulation of complement biosynthesis.
Rat Leukocyte Interferons: Production of an Acid-Labile Interferon After Induction With Newcastle Disease Virus
Authors: Wiedbrauk Danny L , Burleson Gary R
Published: January 2018

Rat leukocytes produce three interferon species after infection with Newcastle disease virus. Two of the three interferon species (22-24,000 and 30,000 daltons) were acid and heat stable, protected rat and mouse cells from virus-mediated cytopathic effect (CPE), and were neutralized by antisera to mouse L-cell (α/β) interferon. The third, 30,000-dalton interferon species was heat and acid labile; protected rat, mouse, human, and bovine cells from virus-mediated CPE; and was neutralized by antisera to mouse L-cell interferon and human leukocyte interferon. Thus, the rat leukocyte interferon system is similar to the human system in the kinetics of interferon production, the production of multiple interferons, heterologous antiviral activity, molecular weight, and in the production of an acid-labile species. The rat leukocyte interferon system therefore represents an important model for examining the normal production and action of acid-labile interferons and their possible role in the regulation of leukocyte function and cellular differentiation.
Characterization of Two Distinct Transglutaminases of Murine Bone Marrow-Derived Macrophages: Effects of Exposure of Viable Cells to Cigarette Smoke on Enzyme Activity
Authors: Roth William J , Fleit Howard B , Chung Soo , Janoff Aaron
Published: January 2018

The present study examines the effects of water soluble extracts of gas-phase cigarette smoke on intracellular transglutaminase activities of intact, murine, bone marrow-derived macrophages maintained in culture. Western blotting of cell lysates utilizing non-cross-reactive antisera indicate that mouse bone marrow-derived macrophages contain both tissue-type transglutaminase and factor Xlll-associated transglutaminase. This finding is also supported by data indicating that the intracellular transglutaminase activity of these cells contains thrombin-dependent and -independent components. Macrophages incubated with cigarette smoke solutions for 15 minutes at 37° display a dose-dependent decrease (maximum inhibition = 55%, p < .001) in tissue-type (thrombin-independent) transglutaminase activity, as compared to control cells incubated with phosphate-buffered saline. Factor XIII (zymogen) is not inactivated following incubation of macrophages with smoke extracts. Smoke exposure under the conditions employed has no effect on either cell viability or adherence. Incubation with 2 μM retinoic acid for 24 hours leads to a modest (2-fold) induction of tissue transglutaminase, but does not induce factor XIII; in contrast, incubation with 10% homologous serum for 24 hours results in a decrease in factor XIII, but does not affect tissue transglutaminase. These data indicate that: 1) bone marrow-derived macrophages contain factor XIII as well as tissue-type transglutaminase; and 2) gas-phase cigarette smoke can inactivate tissue transglutaminase within viable murine bone marrow-derived macrophages, but cannot inactivate zymogenic factor XIII.
Heterogeneity of Human Natural Killer (NK) Cells: Enrichment of NK by Negative-Selection With the Lectin From Erythrina cristagalli
Authors: Harris David T , Iglesias Jose L , Argov Shmuel , Toomey John , Koren Hillel S
Published: January 2018

A novel technique for the isolation and enrichment of human natural killer (NK) cells from peripheral blood mononuclear cells (MNC) is described. Negative selection of MNC with the lectin from Erythrina cristagalli (ECA), whether by panning or agglutination in solution, resulted in a population of lymphocytes (5-20% of original MNC) highly enriched in cells exhibiting NK function. This enrichment was evident by a significant increase (range of 3-50-fold) in cells with large granular lymphocyte (LGL) morphology, K562 tumor-binding cells, cytotoxic activity, and cells expressing NK phenotypic markers (Leu 11+, OKM1+). Analysis of the cytolytic specificity of the cells demonstrated that the lytic spectrum was typical of endogenous NK. The effector cells were responsive to augmentation of cytotoxic potential by lymphokines (IL-2, IFNα, and IFNγ) and capable of antibody-dependent cell-mediated cytotoxicity (ADCC). ECA-negative [ECA(-)] cells were equivalent to NK isolated by Percoll gradient fractionation. NK heterogeneity was demonstrated by the observation of a small percentage (1-5% of MNC) of NK in the ECA(+) population. This technique was found to be advantageous for the study of NK heterogeneity and NK biology.
Role of Epidermal Cell Thymocyte-Activating Factor in the Proliferation and Differentiation of Murine B Cells
Authors: Pillai P S , Reynolds S D , Scott D W , Gauldie J , Sauder D N
Published: January 2018

The role of antigen nonspecific cytokines in T- and B-lymphocyte responses is now well established, interleukin-1 (IL-1) has been shown to augment B-cell maturation and proliferation. While the major source of IL-1 is from monocytes or macrophages, other cell types have been shown to produce IL-1-like cytokines. Epidermal cells produce a cytokine termed “epidermal cell-derived thymocyte-activating factor” (ETAF) which is similar if not identical with monocyte-derived IL-1. In this report we show that ETAF induces polyclonal stimulation of murine B cells. We show that ETAF augments B cell proliferation and differentiation in the absence of any added antigens or mitogens. This activity can be partially inhibited by anti-IL-1 antibodies. ETAF appears to activate B cells directly, although its activity is increased in the presence of T cells. Thus, ETAF may be involved in local polyclonal antibody responses occurring in the skin.
Harvesting the Noncirculating Pool of Polymorphonuclear Leukocytes in Rats by Hetastarch Exchange Transfusion (HET): Yield and Functional Assessment
Authors: Williams James H , Moser Kenneth M , Ulich Thomas , Cairo Mitchell S
Published: January 2018

Isolation of polymorphonuclear leukocytes (PMN) provides an opportunity to study PMN activity in vitro and to label PMN for study of in vivo kinetics. However, simple phlebotomy (SP) of a small animal frequently yields too few PMN for in vitro handling, while PMN harvested from an induced-peritonitis may not accurately reflect PMN in a less stimulated state. We report a novel method of harverting PMN from the circulation of rats, using hetastarch exchange transfusion (HET), which is both time and animal sparing. HET harvested 8-fold more PMN than SP. In vitro cell function was examined with assays of adherence, chemotaxis, bacterial killing, and superoxide generation. No significant (p < 0.05) difference was found between PMN obtained by HET and pooled-PMN obtained by SP. In vivo function was examined following labeling with indium111-oxine. The kinetics pattern described suggested normal migratory activity when compared to previous reports. The data demonstrate that rats possess a relatively large, noncirculating pool of PMN which is readily accessible by HET.
Potentiation of Neutrophil Function by Recombinant DNA-Produced Interleukin 1a
Authors: Ozaki Yukio , Ohashi Tatsuya , Kume Shoji
Published: January 2018

The effect of interleukin 1a (IL-1a) produced by E. coli-derived recombinant DNA was evaluated on various parameters of human neutrophil function. IL-1a alone stimulated neutrophil hydrogen peroxide production in a dose-dependent manner, but the rate was much lower than that of opsonized zymosan. IL-1a induced release of specific granule contents, but not azurophilic granule contents. Cytochalasin B did not augment the rate of release. IL-1a was chemotactic for neutrophils at the optimal concentrations of 0.1-10 ng/ml. Pretreatment of the neutrophils with IL-1a augmented neutrophil oxygen radical production induced by opsonized zymosan, and this synergistic effect was evident as early as 10 min after IL-1a was added to the neutrophil culture. Phagocytosis of opsonized particles by neutrophils, and degranulation induced by opsonized zymosan were also enhanced by IL-1a in a dose-dependent manner. The present results suggest that IL-1a is weak as a direct activator of neutrophil function and that IL-1a in vivo may augment the response of neutrophils to other stimulators such as foreign bodies.
Collection of Leukocytes, Fibroblasts, and Collagen Within an Implantable Reservoir Tube During Tissue Repair
Authors: Diegelmann R F , Kim J C , Lindblad W J , Smith T C , Harris T M , Cohen I K
Published: January 2018

An implantable chamber consisting of a small reservoir and a perforated segment of silicone tubing has been developed for the collection of leukocytes, fibroblasts, and collagen to analyze inflammatory components and fibroplasia during tissue repair. Using aseptic techniques, these sterile chambers were placed into subcutaneous pockets on the backs of Sprague-Dawley rats with cells obtained in daily aspirates for 14 d. Differential cell counts were made by using aliquots from the wound fluid. The aspirated cells represented the characteristic, sequential influx of neutrophils, inflammatory macrophages, lymphocytes, activated macrophages, and fibroblasts documented in other models of tissue repair. On d 14, the connective tissue within the lumen of the silicone tube was removed and analyzed for collagen synthesis by measuring 3H-proline incorporation into collagenase-sensitive protein. This new device for studying wound healing provides a convenient means to harvest cells, fluid, and tissue for cellular, humoral, and biochemical analyses of tissue repair.
Defective Activation of Granuloma Macrophages From Mycobacterium leprae-Infected Nude Mice
Authors: Sibley L David , Krahenbuhl James L
Published: January 2018

We have previously demonstrated that granuloma macrophages from the foot pads of Mycobacterium leprae-infected nude mice are functionally normal despite heavy intracellular burdens of bacilli. However, unlike peritoneal macrophages, these macrophages fail to restrict the intracellular growth of Toxoplasma gondii when stimulated with recombinant murine gamma interferon (Mu IFN-γ) and thus appear defective in their response to macrophage-activating factor(s). In further characterizing this defect we have examined tumoristatic capacity, superoxide radical formation, and expression of Ia antigens on granuloma macrophages before and after treatment with Mu IFN-γ. By all three criteria, M. leprae-burdened granuloma macrophages failed to become activated by doses of Mu IFN-γ that readily activate peritoneal macrophages from M. leprae-infected nude mice or normal Balb/c mice. M. leprae-infected granuloma macrophages produced elevated levels of prostaglandin E2 (PGE2) in vitro, which was suppressed by indomethacin. However, the inhibition of PGE2 production for 48 hr in vitro did not restore normal responses to Mu IFN-γ.
Substratum-Dependent Proliferation and Survival of Bone Marrow-Derived Mononuclear Phagocytes
Authors: Gregory Stephen H
Published: January 2018

Adherence to the culture substratum exerted a significant influence on the growth and survival of murine bone marrow cells incubated under conditions that favored the development of mononuclear phagocytes. Bone marrow cells cultured two weeks in unprocessed polystyrene dishes, refractory to cell attachment, reached a maximum or near maximum cell density by day 11. This density was stable throughout the duration of the incubation period. Characterization of the cells on day 11 revealed an essentially pure population of mononuclear phagocytes composed of round, nonadherent cells, and slightly elongated, loosely attached cells. Bone marrow cells incubated in polystyrene tissue culture dishes processed to promote cell attachment also reached a maximum cell density by day 11. However, this maximum density was only half that attained by cells incubated in unprocessed polystyrene dishes. Furthermore, continued incubation resulted in a sharp decline in cell viability and number. The cells in tissue culture dishes on day 11 represented a pure mononuclear phagocyte population composed principally of cells adherent to the surface of the dish. The subsequent analysis of cells subcultured in processed and unprocessed polystyrene dishes indicated that adherence to the substratum modulated the growth factor requirements of bone marrow-derived mononuclear phagocytes. Specifically, mononuclear phagocytes in tissue culture dishes expressed an elevated requirement for colony stimulating factor-1 in order to proliferate and survive in long-term culture.