bluuebunny/crossref_metadata_2025 huggingface dataset:
Iterative Learning Control for a Type of Modified Smith Predictor
Authors: Tian Dongzuo , Song Xingyong
Published: December 2019

This article proposes a novel iterative learning control (ILC) design for a type of modified Smith predictor, in particular, to control a single-input single-output unstable plant or integral process with a time delay. Frequency domain techniques are applied to synthesize the learning control law, and a sufficient condition is given to ensure robust convergence of the tracking error. Robustness of the system is studied, considering a multiplicative uncertainty. Moreover, the impact of the load disturbance over successive iterations is investigated as well. To this end, a numerical example is given to demonstrate the efficacy of the proposed approach.
Theoretical Analyses of the Number of Backflow Vortices on an Axial Pump or Compressor
Authors: Ito Yu , Sato Yuhei , Nagasaki Takao
Published: December 2019

Backflow vortices occasionally occur in the annular mixing zone between the main and axially reverse whirling flows from the impeller tip clearance on an axial pump or compressor. A number (N) of tornado-like backflow vortices rotate around themselves and revolve around the casing axis with a diameter (d) and a revolving angular velocity (ω). To investigate the factors determining N and the movement of the backflow vortices, theoretical analyses are performed. Each backflow vortex is generated in the mixing zone; the core region of each backflow vortex is considered to be a forced vortex, while the outer region is considered to be a free vortex. The ratio (f) of the forced vortex to the distance between the backflow-vortex center and the casing is defined. Each backflow vortex has a circulation and induces movements of all the other backflow vortices depending on the distance between the vortices. The casing restricts the movements of all the backflow vortices, and imaginary image vortices are considered on the other side of the casing. Consequently, for d, ω, N, and f, any parameter can be determined if the other three parameters are specified. As an application of the present theory to an inducer representing an axial pump or compressor, the number (Ncav) of “backflow-vortex cavitations,” which occur around the backflow-vortex center, is predicted. Cavitation is visible; therefore, Ncav is quantitatively measurable. In the parameter ranges studied for the tested inducer, the predicted value of N accurately agrees with the experimentally measured value of Ncav.
Effect of Eccentric Mass Distribution on the Motion of Spherical Particles in Shear Flows
Authors: Tanaka Mitsuru , Tajiri Kyohei , Nishida Hidetoshi , Yamakawa Masashi
Published: December 2019

A particle-resolved direct numerical simulation is performed on the motion of spherical particles with an eccentric internal mass distribution in lateral linear shear flow, which is oriented in the vertical direction and sheared in a horizontal direction. We examine the effect of mass eccentricity on the two-way interactions of particles with both laminar and turbulent shear flows. A spherical shell/hollow particle with an inner spherical core is focused on as a typical example of mass eccentric particles. The Navier–Stokes equations and the Newton–Euler equations are solved for the fluid phase and the particles, respectively. An immersed boundary method is adopted to represent the shell particle. The Newton–Euler equations are solved using the body-fixed coordinate system and four quaternion parameters, considering the deviation of the center of mass from the center of the spherical shell particle. Simulations are performed at a relatively low particle volume fraction of 0.4%. In turbulent flows, the Taylor-microscale Reynolds number reached about 49 at the end of the simulations. Numerical results show that shear-induced particle rotation is suppressed by the torque due to gravity. It is found that the lateral migration of mass eccentric particles becomes less vigorous in both laminar and turbulent flows since the effect of the Magnus lift force is also weakened for mass eccentric particles. It is also found that the evolution of fluid kinetic energy is significantly affected by the mass eccentricity of particles in laminar flows.
Deep, vertical etching for GaAs using inductively coupled plasma/reactive ion etching
Authors: Booker Katherine , Mayon Yahuitl Osorio , Jones Christopher , Stocks Matthew , Blakers Andrew
Published: December 2019

Deep etched structures in GaAs have many applications in optoelectronics and MEMS devices. These applications often require an anisotropic etch profile with smooth sidewalls as well as a high etch rate and high aspect ratio. Developing an etch process that demonstrates high selectivity for the etch mask is critical as etch times for deep grooves can be protracted due to the effect of RIE lag. In this work, the authors describe etching deep, vertical grooves in GaAs using Inductively Coupled Plasma/Reactive Ion Etching. The effects of RF power, pressure, and gas composition on mask selectivity, etch rate, and anisotropy are discussed. Using a SiO2 etch mask and Cl2 as the main etchant gas, grooves with a vertical sidewall and depths of >120 μm (aspect ratio of 9) have been achieved.
Real-time active suppression of directional acoustic wave components in tubular acoustic systems
Authors: Groves K. H. , Aldughayem O. , Lennox B.
Published: December 2019

Acoustic pulse reflectometry is a method of non-destructive testing used for locating and characterising features and defects in gas-filled objects such as tubes, pipes, and ducts. A sound wave is emitted into the waveguide and travels in the axial direction until it is partially or fully reflected at changes in cross-section. The recorded reflection sequence is analysed to reveal time-of-flight, amplitude, and reflection shape. Analysis of reflection sequences is problematic due to the presence of multiple repeated echoes. The principal contribution is the introduction and demonstration of a method of actively suppressing unwanted echoes by modifying the signal emitted by the speaker in real-time. Unlike previous work, the proposed system accounts for inter-transducer attenuation and does not require re-calibration for each test object. The proposed real-time active absorbing termination is implemented using a programmable embedded controller and shown to function effectively. A quantitative evaluation of available wave separation techniques is provided using a known metric for quantifying the performance of absorbing terminations is introduced.
Localization of sound-producing fish in a water-filled tank
Authors: Novak Antonin , Cisar Petr , Bruneau Michel , Lotton Pierrick , Simon Laurent
Published: December 2019

In this paper, the authors introduce an algorithm for locating sound-producing fish in a small rectangular tank that can be used, e.g., in behavioral bioacoustical studies to determine which fish in a group is sound-producing. The technique consists of locating a single sound source in the tank using signals gathered by four hydrophones placed in the tank together with a group of fish under study. The localization algorithm used in this paper is based on a ratio of two spectra ratios: the spectra ratio between the sound pressure measured by hydrophones at two locations and the spectra ratio between the theoretical Green's functions at the same locations. The results are compared to a localization based on image processing technique and with video recordings acquired synchronously with the acoustic recordings.
Sports Dietitians Australia Position Statement: Nutrition for Exercise in Hot Environments
Authors: McCubbin Alan J. , Allanson Bethanie A. , Caldwell Odgers Joanne N. , Cort Michelle M. , Costa Ricardo J.S. , Cox Gregory R. , Crawshay Siobhan T. , Desbrow Ben , Freney Eliza G. , Gaskell Stephanie K. , Hughes David , Irwin Chris , Jay Ollie , Lalor Benita J. , Ross Megan L.R. , Shaw Gregory , Périard Julien D. , Burke Louise M.
Published: December 2019

It is the position of Sports Dietitians Australia (SDA) that exercise in hot and/or humid environments, or with significant clothing and/or equipment that prevents body heat loss (i.e., exertional heat stress), provides significant challenges to an athlete’s nutritional status, health, and performance. Exertional heat stress, especially when prolonged, can perturb thermoregulatory, cardiovascular, and gastrointestinal systems. Heat acclimation or acclimatization provides beneficial adaptations and should be undertaken where possible. Athletes should aim to begin exercise euhydrated. Furthermore, preexercise hyperhydration may be desirable in some scenarios and can be achieved through acute sodium or glycerol loading protocols. The assessment of fluid balance during exercise, together with gastrointestinal tolerance to fluid intake, and the appropriateness of thirst responses provide valuable information to inform fluid replacement strategies that should be integrated with event fuel requirements. Such strategies should also consider fluid availability and opportunities to drink, to prevent significant under- or overconsumption during exercise. Postexercise beverage choices can be influenced by the required timeframe for return to euhydration and co-ingestion of meals and snacks. Ingested beverage temperature can influence core temperature, with cold/icy beverages of potential use before and during exertional heat stress, while use of menthol can alter thermal sensation. Practical challenges in supporting athletes in teams and traveling for competition require careful planning. Finally, specific athletic population groups have unique nutritional needs in the context of exertional heat stress (i.e., youth, endurance/ultra-endurance athletes, and para-sport athletes), and specific adjustments to nutrition strategies should be made for these population groups.
Effect of Protozoa on Bacterial Degradation of an Aromatic Compound
Authors: Huang Tan-Chi , Chang Miau-Chan , Alexander Martin
Published: December 2019

Prototrophic and growth factor-requiring strains of
Alcaligenes
spp. were used to study the effect of a protozoan,
Tetrahymena pyriformis,
on the degradation of
p
-aminobenzoate. The protozoan inhibited activity of the prototrophic bacterium by reducing its population size. For the growth factor-requiring strain of
Alcaligenes, T. pyriformis
provided the required growth factors so that the predator permitted the bacteria to grow and to continue
p
-aminobenzoate degradation.
T. pyriformis
inhibited bacterial activity when the amino acid supply was in excess, but activity of the auxotrophic strain of
Alcaligenes
was stimulated by the protozoan when the amino acid supply was limiting, although the bacterial population size was reduced by the protozoan.
Induction of Interleukin-4 and Interleukin-5 Expression in Mast Cells Is Inhibited by Glucocorticoids
Authors: Sewell William A. , Scurr Lyndee L. , Orphanides Helen , Kinder Simon , Ludowyke Russell I.
Published: December 2019

Inflammation in asthma and other allergic diseases is characterized by excessive production of immunoglobulin E (IgE) and the influx of leukocytes, especially eosinophils. Interleukin 4 (IL-4) and IL-5 are essential for IgE production and eosinophilia, respectively, and are produced by mast cells in allergic conditions, for which glucocorticoids are widely used therapeutically. We assessed the effect of glucocorticoids on IL-4 and IL-5 mRNA production by the RBL-2H3 cell line, an analog of mucosal mast cells. IL-4 and IL-5 mRNAs were induced by an antigen that is used to cross-link receptor bound IgE, by calcium ionophore, or by ionophore with phorbol ester and were markedly inhibited by dexamethasone. In cells activated with ionophore and phorbol ester, 10−6M dexamethasone reduced the IL-4 and IL-5 mRNA levels to only 12.8 and 5.7%, respectively, of those in cells without dexamethasone, and 10−9M dexamethasone caused reductions to 27 and 56%, respectively. Hydrocortisone at 10−6and 10−7M almost completely inhibited IL-4 and IL-5 mRNA production. Dexamethasone was markedly inhibitory even if it was added after the cells were activated, provided that it was present in the cultures for at least 1.5 h. These studies indicate that the expression of IL-4 and IL-5 mRNAs by mast cells is highly sensitive to glucocorticoids. The data suggest that these inhibitory effects may contribute to the clinical efficacy of glucocorticoids in the therapy of allergic diseases.
Antibody to
Pneumocystis carinii
Protects Rats and Mice from Developing Pneumonia
Authors: Bartlett Marilyn S. , Angus William C. , Shaw Margaret M. , Durant Pamela J. , Lee Chao-Hung , Pascale Juan M. , Smith James W.
Published: December 2019

Well-proven mouse and rat models were used to show that polyclonal antisera to
Pneumocystis carinii
protect against
P. carinii
pneumonia. Antibodies were obtained from animals that were allowed to recover from severe
P. carinii
pneumonia after immunosuppression had been stopped and which then were given a booster injection of
P. carinii
from the same animal species. Mice immunosuppressed with corticosteroids or antibodies to L3T4
+
lymphocytes (which are comparable to CD4 cells of humans) and transtracheally inoculated with mouse
P. carinii
did not develop
P. carinii
pneumonia if they were passively immunized with antiserum, while mice immunosuppressed and inoculated by identical procedures but not given antibodies developed severe infections. Rats immunosuppressed with corticosteroids and inoculated with rat
P. carinii
had less severe infections if they were given rat anti-
P. carinii
antisera. The polyclonal antisera developed in mice provided greater protection for the mice than the polyclonal rat antisera did for the rats; however, the potencies and compositions of the antisera were not quantitated and probably differed. Since both rats and mice can be protected from
P. carinii
infections with polyclonal antisera, it may be possible to develop vaccines that will elicit protective antibodies in humans.
Immunofluorescence Microscopy and Flow Cytometry Characterization of Chemical Induction of Latent Epstein-Barr Virus
Authors: Jenson Hal B. , Grant George M. , Ench Yasmin , Heard Patty , Thomas Charles A. , Hilsenbeck Susan G. , Moyer Mary Pat
Published: December 2019

The effects of chemical induction of latent Epstein-Barr virus (EBV) with 12-
O
-tetradecanoyl phorbol-13-acetate (TPA) and
n
-butyrate on cell viability and induction of latent EBV in Raji and X50-7 B lymphocytes, indicated by expression of the diffuse component of the EBV early antigen (EA-D), were measured by visual immunofluorescence microscopy (of both viable and nonviable cells) and fluorescence-activated cell sorter (FACS) flow cytometry (of viable cells only). Cell viability at 4 days decreased moderately for treated Raji cells (9 to 37%, compared to 55 to 69% for untreated cells) and markedly for X50-7 cells (1-32% compared to 35-44% in untreated cells). The highest EA-D levels in viable cells occurred in Raji cells treated with both TPA and
n
-butyrate and untreated X50-7 cells. TPA and
n
-butyrate acted synergistically to induce latent EBV, resulting in increased levels of EA-D production in Raji cells and cell death in X50-7 cells. Methodological differences including the ability to detect antigen in only viable cells by FACS flow cytometry accounted for the higher levels of EA-D observed by FACS analysis compared to the levels observed by immunofluorescence microscopy. FACS analysis may be more objective and reproducible than immunofluorescence microscopy for the detection of EBV induction and also permits viral protein expression to be distinguished in the subpopulation of viable cells.
The Different Binding Patterns of Two Immunoglobulin M Monoclonal Antibodies toCryptococcus neoformansSerotype A and D Strains Correlate with Serotype Classification and Differences in Functional Assays
Authors: Cleare Wendy , Casadevall Arturo
Published: December 2019

Cryptococcus neoformansvar.neoformansstrains have historically been divided into serotypes A and D on the basis of reactivity with rabbit sera. Previously, we noted that two murine immunoglobulin M monoclonal antibodies (MAbs) to the capsular glucuronoxylomannan produced different indirect immunofluorescence (IF) patterns, described as annular and punctate, when bound toC. neoformanscells from different strains. In this study, we examined the reactivity of these two MAbs, known as 12A1 and 13F1, with 20C. neoformansvar.neoformansstrains, of which 13 were serotype A and 7 were serotype D. For all strains, MAb binding was studied by IF and agglutination assays. In addition, we blindly tested the IF patterns of 22C. neoformansvar.neoformansstrains. For selected strains, MAb binding was studied by flow cytometry (FACScan) and phagocytosis assays. The epitopes recognized by MAbs 12A1 and 13F1 were found in all of the strains. MAb 12A1 binding produced an annular IF pattern with all of the strains, irrespective of the serotype classification. MAb 13F1 binding produced annular binding with all of the serotype A strains and punctate binding with 19 of 20 serotype D strains. In general, the punctate IF pattern was associated with lower fluorescence intensity, a requirement for higher antibody concentrations to produce yeast cell agglutination, and lower opsonic efficacy. Our results provide strong support for the existing classification of two serological types for strains assigned to varietyneoformansand indicate qualitative and quantitative antigenic differences among serotype A and D strains.
Evaluation of an Immunoglobulin G Enzyme-Linked Immunosorbent Assay for Pertussis Toxin and Filamentous Hemagglutinin in Diagnosis of Pertussis in Senegal
Authors: Simondon François , Iteman Isabelle , Preziosi Marie Pierre , Yam Abdoulaye , Guiso Nicole
Published: December 2019

The enzyme-linked immunosorbent assay is widely employed for the serological diagnosis of pertussis. It is generally concluded that a significant increase in specific immunoglobulin G (IgG) or IgA against the pertussis toxin (PT) or against filamentous hemagglutinin (FHA) in paired sera correlates withBordetella pertussisinfection. However, this type of diagnosis of pertussis has mainly been applied to unvaccinated children, with timely sampling of acute- and convalescent-phase sera. In current practice and in epidemiological studies, such criteria are not always fulfilled. The aim of this study was to analyze the significance of decreases in IgG antibody titers against PT and FHA between paired sera observed in suspected cases of pertussis infection. Serological results from paired sera were available for 460 children experiencing at least 8 days of cough. An anti-PT IgG decrease was observed in 25% of the children, more frequently than the anti-FHA IgG decrease. Fourteen percent of the serologic decreases were observed in children with culture-confirmed infection, and 59% of the decreases were observed in children with confirmation criteria according to World Health Organization recommendations. Most of the decreases were observed when serum samples were collected according to a standard recommended schedule. Serologic decreases were observed more frequently among vaccinated children than among unvaccinated children. This difference, which was highly significant (P< 0.00001), was explained by the different kinetics of the antibody responses between vaccinated and unvaccinated children. The importance of the antibody response for the evaluation of vaccine efficacy, namely a bias toward higher absolute vaccine efficacy when this response is not taken into account, is discussed. This study supports an earlier recommendation that a significant decrease in PT or FHA should be added to the diagnostic criteria for pertussis.
vacA
Genotypes and Genetic Diversity in Clinical Isolates of
Helicobacter pylori
Authors: Han Shan-Rui , Schreiber Hans-Joachim , Bhakdi Sucharit , Loos Michael , Maeurer Markus J.
Published: December 2019

Genetic diversity in
Helicobacter pylori
strains may affect the function and antigenicity of virulence factors associated with bacterial infection and, ultimately, disease outcome. In this study, DNA diversity of
H. pylori
isolates was examined by analysis of
vacA
genotypes and by restriction fragment length polymorphism (RFLP) analysis of
H. pylori
-associated genes (
vacA
,
cagA
,
flaA
,
ureAB
, and
ureCD
). Thirty-seven
H. pylori
isolates from 26 patients were successfully classified into distinct
vacA
allelic genotypes. The signal sequence allele s1 (31 of 37) predominated over the s2 allele (6 of 37) and was significantly associated with the occurrence (past or present) of gastric ulcers. A novel midregion allele, designated as m3, has been identified in two
H. pylori
isolates which could not be typed with midregion allele m1- or m2-specific primers. Additionally, significant nucleotide diversity yielding different amino acid sequences was demonstrated by DNA sequencing of
vacA
fragments from clinical isolates of
H. pylori
. Furthermore, RFLP analysis of 45
H. pylori
isolates (including 15 paired isolates) obtained from antrum and corpus biopsy specimens from 30 individual patients showed remarkably high interhost diversity (one patient, one
H. pylori
strain) and intrahost identity in gene sequences coding for VacA, CagA, flagellin, and urease. Only in a single patient was a minor genotypic variation at different anatomic sites within the stomach identified. These data warrant the detailed analysis of the effect of genetic diversity on the function and antigenicity of
H. pylori
-associated virulence factors.
Rapid Detection of Antigenic Diversity of Akabane Virus Isolates by Dot Immunobinding Assay Using Neutralizing Monoclonal Antibodies
Authors: Yoshida Kazuo , Tsuda Tomoyuki
Published: December 2019

Akabane (AKA) virus is an arthropod-borne virus belonging to the Simbu group of the genus
Bunyavirus
. Neutralizing monoclonal antibodies (MAbs) against AKA virus were prepared, and the neutralizing epitopes of the virus were defined by competitive binding assay. Five distinct antigenic domains were identified and were designated A, B, C, D, and E. Domains A and C consisted of two epitopes each. It was demonstrated that seven neutralizing epitopes exist on the G1 glycoprotein of AKA virus. Dot immunobinding assays (DIAs) were performed with MAbs which recognize these seven neutralizing epitopes. The results were similar to those obtained by enzyme-linked immunosorbent assay. DIAs were performed using two Australian strains, one isolate from Taiwan, and isolates from Japan collected between the years 1959 and 1994, for a total of 63 isolates. The MAb response patterns were divided into five groups: the OBE-1 strain, the JaGAr39 strain, the Iriki strain, a group which consisted of features between those of the JaGAr39 strain and Iriki strain groups, and a group which did not belong to any of these patterns. The isolates which showed patterns similar to that of the JaGAr39 strain were found mostly among the isolates collected in 1974 and 1990, and isolates with patterns of MAb responses similar to the pattern of the Iriki strain were found mostly in the 1985 isolates. Those showing patterns in between were found mostly around 1977, 1987, and 1994. The results show that DIA can be used to effectively compare the antigenicities of AKA virus isolates within a few hours, even with lesser amounts of virus culture than is required for other assays.
Involvement of Antilipoarabinomannan Antibodies in Classical Complement Activation in Tuberculosis
Authors: Hetland Geir , Wiker Harald G. , Høgåsen Kolbjørn , Hamasur Beston , Svenson Stefan B. , Harboe Morten
Published: December 2019

We examined alternative and classical complement activation induced by whole bacilli ofMycobacterium bovisBCG andMycobacterium tuberculosisproducts. After exposure to BCG, there were higher levels of the terminal complement complex in sera from Indian tuberculosis patients than in sera from healthy controls. The addition of BCG with or without EGTA to these sera indicated that approximately 70 to 85% of the total levels of the terminal complement complex was formed by classical activation. Sera from Indian tuberculosis patients contained more antibody to lipoarabinomannan (LAM) than sera from healthy Indians. Levels of anti-LAM immunoglobulin G2 (IgG2), but not anti-LAM IgM, correlated positively with classical activation induced by BCG in the sera. By flow cytometry, deposition of C3 and terminal complement complex on bacilli incubated with normal human serum was demonstrated. The anticomplement staining was significantly reduced in the presence of EGTA and EDTA. Flow cytometry also revealed the binding of complement to BCG incubated with rabbit anti-LAM and then with factor B-depleted serum. This indicates that classical activation plays a major role in complement activation induced by mycobacteria and that anti-LAM IgG on the bacilli can mediate this response. Classical complement activation may be important for the extent of phagocytosis ofM. tuberculosisby mononuclear phagocytes, which may influence the course after infection.
A Simple Whole-Blood Test for Detecting Antibodies to Human Immunodeficiency Virus
Authors: Schramm Willfried , Wade Stephen E. , Angulo Gustavo Barriga , Torres Patricia Castillo , Burgess-Cassler Anthony
Published: December 2019

We developed an immunochromatographic whole-blood test (WBT) which detects antibodies to human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) from fingerstick blood. The sensitivity and specificity of the WBT were 99.41% (1,018 confirmed positive patients) and 99.89% (941 uninfected patients), respectively (enzyme immunoassay [EIA] on serum or plasma as a reference). WBT performance was comparable to those of licensed EIAs and Western blotting, using 18 HIV-2 sera, 23 HIV-1 seroconversion panels, and a low-titer performance panel (in lieu of whole blood).
Serotype Specificity of the Neutralizing-Antibody Response Induced by the Individual Surface Proteins of Rotavirus in Natural Infections of Young Children
Authors: Menchaca Griselda , Padilla-Noriega Luis , Méndez-Toss Martha , Contreras Juan F. , Puerto Fernando I. , Guiscafré Hector , Mota Felipe , Herrera Ismael , Cedillo Roberto , Muñoz Onofre , Ward Richard , Hoshino Yasutaka , López Susana , Arias Carlos F.
Published: December 2019

The relative contribution of the rotavirus surface proteins, VP4 and VP7, to the induction of homotypic as well as heterotypic neutralizing antibodies (NtAbs) in natural infections was studied. The NtAb titers of paired sera from 70 infants with serologically defined primary rotavirus infections were determined with a panel of rotavirus reassortants having one surface protein from a human rotavirus (serotypes G1 to G4 for VP7 and P1A and P1B for VP4) and the other surface protein from a heterologous animal rotavirus strain. A subset of 37 children were evaluated for epitope-specific antibodies to the two proteins by an epitope-blocking assay. The infants were found to seroconvert more frequently to VP4 than to VP7 by both methods, although the titers of the seroconverters were higher to VP7 than to VP4. Both proteins induced homotypic as well as heterotypic NtAbs. G1 VP7 frequently induced a response to both G1 and G3 VP7s, while G3 VP7 and P1A VP4 induced mostly homotypic responses.
The Tumor Necrosis Factor-Inducing Potency of Lipopolysaccharide and Uronic Acid Polymers Is Increased when They Are Covalently Linked to Particles
Authors: Berntzen Gøril , Flo Trude H. , Medvedev Andrei , Kilaas Lars , Skjåk-Bræk Gudmund , Sundan Anders , Espevik Terje
Published: December 2019

Lipopolysaccharide (LPS) and polymers of the uronic acid family stimulate monocytes to produce tumor necrosis factor (TNF). The TNF-inducing potency of these polysaccharides may depend on their supramolecular configuration. In this study detoxified LPS and uronic acid polymers have been covalently linked to particles which have been added to monocytes under serum-free conditions. Reducing the size of mannuronan from 350,000 to 5,500 Da (M-blocks) led to a 10- to 100-fold reduction in TNF-inducing potency. However, covalently linking the M-blocks to monodisperse suspensions of magnetic particles increased the TNF-inducing potency by up to 60,000-fold. Also, the TNF-inducing potency of glucuronic acid polymers was increased when they were linked to particles, but no potentiation was observed with guluronic acid blocks covalently attached to particles. Furthermore, O chains of LPS (detoxified LPS) became potent TNF inducers when they were presented to monocytes on a particle surface. No activation of the LPS-responsive SW480 adenocarcinoma cells was found with detoxified LPS or M-block particles, suggesting a preference for cells expressing CD14 and/or other membrane molecules. The potentiating effects were not restricted to polymers attached to aminated magnetic particles. Of particular interest, we found that short blocks of mannuronan induced TNF production also when covalently linked to biodegradable, bovine serum albumin particles.
Immunohistochemical Detection of Porcine Epidemic Diarrhea Virus Compared to Other Methods
Authors: Guscetti Franco , Bernasconi Curzio , Tobler Kurt , Van Reeth Kristien , Pospischil Andreas , Ackermann Mathias
Published: December 2019

An immunohistochemistry method using formalin-fixed tissues, a direct immunofluorescence method using cryostat sections, an enzyme-linked immunosorbent assay (ELISA), and a PCR method were compared for diagnosis in a litter of weaned pigs that had been experimentally inoculated with wild-type porcine epidemic diarrhea virus (PEDV) and killed between 6 and 60 h after onset of diarrhea. The immunohistochemistry method proved to be as reliable as direct immunofluorescence for diagnosis of PEDV in tissues collected postmortem. The good reliability of ELISA for investigating clinical samples was confirmed, whereas the PCR method used was ineffective.
T Cells and T-Cell Cytokine Transcripts in the Synovial Membrane in Patients with Osteoarthritis
Authors: Sakkas Lazaros I. , Scanzello Carla , Johanson Norman , Burkholder Janet , Mitra Amitabha , Salgame Padmini , Katsetos Christos D. , Platsoucas Chris D.
Published: December 2019

The synovial membrane in osteoarthritis (OA) often exhibits inflammatory infiltrates, but the role of T cells in these infiltrates is not known. T-cell activation antigens were analyzed by immunohistochemistry, and T-cell cytokine transcripts were measured by competitive PCR in synovial membranes from patients with OA and rheumatoid arthritis (RA). Lymphoid cell aggregates, containing primarily CD3+T lymphocytes, were found in 65% of patients with OA. Mononuclear cells expressing the activation antigens CD69, CD25, CD38, CD43, CD45RO, and HLA class II were present in both patient groups, although in higher numbers in patients with RA. Interleukin 2 (IL-2) transcripts were found in 10 of 18 patients with OA versus 12 of 13 patients with RA (P= 0.03). Gamma interferon (IFN-γ) transcripts were detected in 9 of 18 patients with OA versus 10 of 13 patients with RA (not significant), whereas IL-10 transcripts were found in nearly all patients. IL-4 and IL-5 were not detected in any patients. The levels of IFN-γ and IL-2 transcripts, normalized for T-cell number equivalents, were not statistically different between OA and RA, but the levels of IFN-γ, normalized for total cell number equivalents, were lower in OA than in RA (P= 0.01). Synovial membranes that expressed IL-2 and IFN-γ transcripts were more likely to have heavier infiltrations of T cells and cells bearing activation markers than synovial membranes that did not express these cytokines. The presence of activated T cells and TH1 cytokine transcripts in chronic joint lesions of patients with OA suggests that T cells contribute to chronic inflammation in a large proportion of these patients.
Intrathecal Synthesis of Immunoglobulins in Eosinophilic Meningoencephalitis Due to
Angiostrongylus cantonensis
Authors: Dorta-Contreras Alberto Juan , Reiber Hansotto
Published: December 2019

Eosinophilic meningoencephalitis due to the nematode
Angiostrongylus cantonensis
, which is endemic to Cuba, occurs in children and is due to accidental contact with soil snails. The course is less often fatal than in adult patients in southeastern Asia. Cerebrospinal fluid (CSF) and serum samples from 24 pediatric patients were analyzed and evaluated in CSF/serum quotient diagrams (Reiber graphs) to characterize the neuroimmunological response and the blood-CSF barrier dysfunction that occur in the course of the disease. At the time of the first diagnostic lumbar puncture, together with eosinophilic pleocytosis (1,920 ± 400 cells/μl), intermediate blood-CSF barrier dysfunction (i.e., an increased CSF/serum albumin quotient) with no intrathecal immunoglobulin G (IgG), IgA, and IgM class response was observed in all cases. Seven days later, at the time of early clinical recovery, the blood-CSF barrier dysfunction was normalized in 75% of the patients, but meanwhile, intrathecal immunoglobulin synthesis emerged in all cases, as either a two-class response (IgG and IgA in 85% of the patients) or a three-class response (IgG, IgA, and IgM; 30%). The fraction of eosinophilic cells (40%) remained large despite a decreasing total cell count. The neuroimmunological pattern of this inflammatory response to the parasite and its toxins is discussed with regard to the CSF patterns of other infectious diseases caused by bacteria or viruses.
Human Immunodeficiency Virus Type 1 Disease Progression, CCR5 Genotype, and Specific Immune Responses
Authors: Visco-Comandini Ubaldo , Hultgren Catharina , Broström Christina , Birk Markus , Kim Soo , Sällberg Matti
Published: December 2019

The correlation among the presence of a 32-bp deletion in the CC-chemokine receptor 5 (
CCR5
) gene, disease progression, and human immunodeficiency virus type 1 (HIV-1)-specific immune responses was analyzed for a cohort of 79 Caucasian HIV-1-infected patients. The
CCR5
genotype (
CCR5/CCR5
= wild type/wild type or Δ
32CCR5/CCR5
= 32-bp deletion/wild type) in peripheral blood mononuclear cells was determined by PCR, followed by sequencing of both wild-type and Δ
32CCR5
gene fragments. HIV-1-specific humoral responses to gp41 and V3
MN
peptides were determined by enzyme immunoassays. The prevalence of the Δ
32CCR5
allele was lower among 37 patients with rapid progression (progression to AIDS or to a CD4 cell count of <200 × 10
6
/liter in less than 9 years;
P
< 0.01) compared to that for 42 patients with slow progression (no AIDS and CD4 cell count of >200 × 10
6
/liter after at least 9 years from infection) or to that for 25 non-HIV-1-infected Swedish blood donors (
P
< 0.05). No differences were observed in the wild-type
CCR5
sequences between the different groups of patients. For three analyzed patients, the 32-bp Δ
32CCR5
gene deletions were identical. The antibody titers against gp41 and a V3
MN
peptide in patients with the Δ
32CCR5/CCR5
genotype were not significantly different from those in pair-matched
CCR5/CCR5
controls. However, in 13 analyzed patients, a stronger serum neutralizing activity was associated with the Δ
32CCR5/CCR5
genotype. Thus, a
CCR5/CCR5
genotype correlates with a shortened AIDS-free HIV-1 infection period and possibly with a worse neutralizing activity, without an evident influence on the antibody response to two major antigenic regions of HIV-1 envelope.
A Modified Enzyme-Linked Immunosorbent Assay for Measurement of Antibody Responses to Meningococcal C Polysaccharide That Correlate with Bactericidal Responses
Authors: Granoff Dan M. , Maslanka Susan E. , Carlone George M. , Plikaytis Brian D. , Santos George F. , Mokatrin Ahmad , Raff Howard V.
Published: December 2019

The standardized enzyme-linked immunosorbent assay (ELISA) for measurement of serum immunoglobulin G (IgG) antibody responses to meningococcal C polysaccharide has been modified to employ assay conditions that ensure specificity and favor detection primarily of high-avidity antibodies. The modified and standard assays were used to measure IgG antibody concentrations in sera of toddlers vaccinated with meningococcal polysaccharide vaccine or a meningococcal C conjugate vaccine. The results were compared to the respective complement-mediated bactericidal antibody titers. In sera obtained after one or two doses of vaccine, the correlation coefficients,r, for the results of the standard assay and bactericidal antibody titers were 0.45 and 0.29, compared to 0.85 and 0.87, respectively, for the modified assay. With the standard assay, there were no significant differences between the geometric mean antibody responses of the two vaccine groups. In contrast, with the modified assay, 5- to 20-fold higher postvaccination antibody concentrations were measured in the conjugate than in the polysaccharide group. Importantly, the results of the modified assay, but not the standard ELISA, paralleled the respective geometric mean bactericidal antibody titers. Thus, by employing conditions that favor detection of higher-avidity IgG antibody, the modified ELISA provides results that correlate closely with measurements of antibody functional activity that are thought to be important in protection against meningococcal disease.
Concentrations of Circulating β-Chemokines Do Not Correlate with Viral Load in Human Immunodeficiency Virus-Infected Individuals
Authors: Kakkanaiah Vellalore N. , Ojo-Amaize Emmanuel A. , Peter James B.
Published: December 2019

The CC or β-chemokines MIP-1α, MIP-1β, and RANTES are the primary components of human immunodeficiency virus type 1 (HIV-1)-suppressive soluble factors in vitro. We studied the relationship between the concentrations of MIP-1α, MIP-1β, and RANTES in plasma and HIV viral load in HIV-infected subjects. The HIV-positive patient group (n= 140) had significantly lower concentrations of all three β-chemokines (MIP-1α,P< 0.0005; MIP-1β,P< 0.005; RANTES,P< 0.0005) than the control group (n= 58 for MIP-1α,n= 27 for MIP-1β, andn= 59 for RANTES). In addition, we divided the patient group into three subgroups (high, moderate, and low) based on the number of HIV-1 RNA copies in the plasma (as measured by quantitative HIV RNA PCR). Again, all three subgroups had significantly lower concentrations of the β-chemokines than the HIV-negative control group. However, there was no significant difference in plasma β-chemokine concentrations among the three subgroups within the patient group (P< 0.3). Although our results demonstrate that HIV-infected individuals had significantly lower concentrations of circulating β-chemokines than healthy uninfected control subjects, we found no correlation between the concentrations of β-chemokines in plasma and HIV-1 viral load in HIV-infected individuals.
Oral Fluids as an Alternative to Serum for Measurement of Markers of Immune Activation
Authors: Nishanian Parunag , Aziz Najib , Chung Joanie , Detels Roger , Fahey John L.
Published: December 2019

Oral fluids are convenient alternatives to blood sampling for evaluating significant metabolic components. Two forms of oral fluids, oral mucosal transudates (OMT) and saliva, were collected and compared for content of soluble products of immune activation. The data confirm that OMT and saliva represent distinct body fluids. The concentrations, outputs, and analyte/protein ratios of β-2-microglobulin (β2M), soluble tumor necrosis factor alpha receptor II (sTNFαRII), and neopterin were measured. Both the OMT and the saliva of most of the individuals in the control healthy populations had measurable levels of all three activation markers. When the immune system is activated, as in human immunodeficiency virus (HIV) infection, the levels of β2M and sTNFαRII are increased in both OMT and saliva compared to those in a healthy control population. OMT levels correlated better with levels in serum than did saliva and appear to reflect systemic immune activation in HIV infection. Because acquisition of oral fluids is noninvasive and easily repeatable, measurement of β2M and/or sTNFαRII content in OMT could be useful in the assessment of disease activity in patients with HIV infection or chronic inflammatory diseases.
Interpretations of Antibody Responses toSalmonella entericaSerotype Enteritidis gm Flagellin in Poultry Flocks Are Enhanced by a Kinetics-Based Enzyme-Linked Immunosorbent Assay
Authors: McDonough Patrick L. , Jacobson Richard H. , Timoney John F. , Mutalib Ahmed , Kradel David C. , Chang Yung-fu , Shin Sang J. , Lein Donald H. , Trock Susan , Wheeler Kaye
Published: December 2019

Many regulatory and diagnostic programs for the detection ofSalmonella entericaserotype Enteritidis infection in commercial poultry flocks have relied on rapid Pullorum agglutination tests to screen birds because of the shared antigens ofS. entericaEnteritidis andS. entericaPullorum and Gallinarum; however, the use of the enzyme-linked immunosorbent assay (ELISA) format affords better analytical sensitivity than crude agglutination tests. In this study, we adapted our earlier conventional indirect ELISA, using gm flagellin as the antigen, to a kinetics-based, computer-controlled ELISA (KELA). The KELA was used to screen for flagellin antibody from three commercial flocks: (i) a large flock involved in a U.S. Department of Agriculture trace back from a humanS. entericaEnteritidis foodborne outbreak (n= 3,209), (ii) a flock infected with the endemicS. entericaEnteritidis serotype but which also had multiple other salmonella serotypes (n= 65), and (iii) anS. entericaPullorum-infected flock (n= 12). The first flock (S. entericaEnteritidis prevalence of 2.45% based on culture) provided a field test of the KELA and allowed the calculation of diagnostic sensitivity (D-Sn) and diagnostic specificity (D-Sp). With a cutoff of 10 (used for screening flocks [i.e., high sensitivity]), the KELA has a D-Sn of 95.2% and a D-Sp of 18.5%; with a cutoff of 140 (used in confirmatory flock testing [i.e., high specificity]), the KELA has a D-Sn of 28.0% and a D-Sp of 99.1%. We found that with a cutoff of 60 (D-Sn = 63.1%; D-Sp = 91.6%), we could eliminate reactions in the KELA caused by other non-S. entericaEnteritidis salmonellae. The KELA was also compared to two commercial rapid Pullorum tests, the Solvay (D-Sn = 94.9%; D-Sp = 55.5%) and the Vineland (D-Sn = 62.0%; D-Sp = 75.3%).
Quantifying Serum Antiplague Antibody with a Fiber-Optic Biosensor
Authors: Anderson George P. , King Keeley D. , Cao Lynn K. , Jacoby Meagan , Ligler Frances S. , Ezzell John
Published: December 2019

The fiber-optic biosensor, originally developed to detect hazardous biological agents such as protein toxins or bacterial cells, has been utilized to quantify the concentration of serum antiplague antibodies. This biosensor has been used to detect and quantify the plague fraction 1 antigen in serum, plasma, and whole-blood samples, but its ability to quantify serum antibodies has not been demonstrated. By using a competitive assay, the concentration of serum antiplague antibodies was ascertained in the range of 2 to 15 μg/ml. By making simple dilutions, concentrations for 11 serum samples whose antiplague antibody concentrations were unknown were determined and were found to be in good agreement with enzyme-linked immunosorbent assay results. The competitive assay method could be used to effectively determine the exposure to plague of animals or humans or could be applied to other diseases, such as hepatitis or AIDS, where the presence of antibodies is used to diagnose infection.
Analysis of Specific Immunoglobulin G Subclass Antibodies for Serological Diagnosis of Echinococcosis by a Standard Enzyme-Linked Immunosorbent Assay
Authors: Grimm Felix , Maly Friedrich E. , Lü Jian , Llano Roberto
Published: December 2019

The potential roles of specific antibodies of the different immunoglobulin G (IgG) subclasses in the serological diagnosis of cystic echinococcosis (CE) and alveolar echinococcosis (AE) were investigated by an enzyme-linked immunosorbent assay based on hydatid fluid as antigen. Specific antibodies of subclass 1 were found to be of major importance. In sera collected at the time of diagnosis (i.e., before any therapeutic intervention was initiated) they could be demonstrated in 14 of 15 sera from patients with CE and in all 12 sera from patients with AE. The most discriminatory and the most specific antibodies found in this study belonged to IgG subclass 4. Only one false-positive reaction was observed with 253 sera from healthy volunteers, and no cross-reactions occurred in 80 sera from patients with different parasitic infections. Specific IgG4 antibodies could be demonstrated in 61.0 to 66.7% (CE) or 47.6 to 66.7% (AE) of the cases. Antibody levels of IgG subclass 2 were elevated only moderately, and subclass 3 antibodies were detected in a few cases only. In addition, nonspecific reactions in sera of healthy volunteers or patients with other parasitic infections could partially be attributed to antibodies of subclasses 2 and 3.
Enzyme Immunoassays for Serological Diagnosis of Bovine Brucellosis: A Trial in Latin America
Authors: Gall D. , Colling A. , Marino O. , Moreno E. , Nielsen K. , Perez B. , Samartino L.
Published: December 2019

The results of a field trial conducted in Latin America with two indirect enzyme-linked immunosorbent assays (ELISAs) and two competitive ELISAs (CELISAs) for the detection of bovine antibody to
Brucella abortus
are reported. One of the CELISA formats performed most accurately. The percentage of positive reactions in the CELISA relative to the selected positive rose bengal agglutination test (RBT) and complement fixation test (CFT) results was 97.47%, the percentage of negatives relative to the selected negative RBT and CFT results for unexposed cattle was 98.32%, and the percentage of negatives in cattle vaccinated with
B. abortus
19 was 96.51%. The same assay format under Canadian conditions had an actual sensitivity of 100%, a specificity of 99.90% in nonvaccinates, and a specificity of 97.7% in a strain 19-vaccinated population. Overall, the CELISA performed as expected and the results were not dissimilar from the results obtained in the Canadian study. This provided further evidence that this CELISA can in many instances differentiate infected cattle from those that are vaccinated or infected with a cross-reacting organism while still giving very few false-positive or false-negative results.
Endothelial Cells Expressing an Inflammatory Phenotype Are Lysed by Superantigen-Targeted Cytotoxic T Cells
Authors: Riesbeck Kristian , Billström Anita , Tordsson Jesper , Brodin Thomas , Kristensson Karin , Dohlsten Mikael
Published: December 2019

The objective of this study was to investigate whether the superantigen staphylococcal enterotoxin A (SEA), which binds to HLA class II and T-cell receptor Vβ chains, can direct cytotoxic T cells to lyse cytokine-stimulated endothelial cells (EC). In addition, we wanted to determine whether SEA-primed cytotoxic T cells could be targeted to EC surface molecules as a means of a novel cancer immunotherapy. Human umbilical vein EC (HUVEC), dermal microvascular EC (HMVEC), or the EC line EA.hy926 stimulated with gamma interferon (IFN-γ) or tumor necrosis factor alpha (TNF-α) displayed upregulated HLA class II and adhesion molecule (CD54 and CD106) expression, respectively. SEA-primed T cells induced a strong cytotoxicity against IFN-γ- and TNF-α-activated EA.hy926 which had been preincubated with SEA. Blocking of CD54 completely abrogated the T-cell attack. SEA-D227A, which has a mutated class II binding site, did not promote any cytotoxicity. A strong lysis was observed when a fusion protein consisting of protein A and SEA-D227A was added together with T cells to TNF-α-induced EA.hy926 and HUVEC precoated with monoclonal antibodies (MAb) directed against HLA class I, CD54, or CD106 molecules. Finally, an scFv antibody fragment reactive with an unknown EC antigen was fused with SEA-D227A. Both EA.hy926 and HMVEC were efficiently lysed by scFv-SEA-D227A-triggered cytotoxic T cells. Taken together, superantigen-activated T-cell-dependent EC killing was induced when EC expressed an inflammatory phenotype. Moreover, specific MAb targeting of the superantigen to surface antigens induced EC lysis. Our data suggest that directed T-cell-mediated lysis of unwanted proliferating EC, such as those in the tumor microvasculature, can be clinically useful.