bluuebunny/crossref_metadata_2025 huggingface dataset:
Thixotropy and Plasticity. III—The Effect of Thixotropy upon Plasticity Measurements
Authors: McMillen Elliott L.
Published: January 2006

The first two papers of this series have dealt entirely with thixotropy, while this paper deals with plasticity as it is affected by the presence of thixotropy. Several rather revolutionary conclusions will be arrived at for which the experimental proof cannot as yet be considered adequate. An attempt will be made to show the line of reasoning that leads to these conclusions.
Future Problems of Theoretical Rheology
Authors: Hersey Mayo D.
Published: January 2006

Theoretical Rheology deals with the definitions, physical concepts, and mathematical relations governing both the intrinsic flow-characteristics or rheological properties of materials, and the resultant flow-phenomena that may occur under stated conditions. The field of Theoretical Rheology need not be restricted to the study of problems for which a purely deductive solution can be found, but may be considered as including also the scientific planning and interpretation of experimental work.
Purification of Materials by Vacuum Distillation
Authors: Flosdorf Earl W. , Palmer Arthur E.
Published: January 2006

It is highly desirable in vacuum distillation for the purification of materials to be able to split the fractions of distillate without interrupting the distillation itself. Inasmuch as only the two fractions are required, the low boiling and the pure material fractions, the apparatus illustrated in the accompanying diagram serves the purpose exceedingly well: a distilling flask, F, with two side arms. Two additional arms could be provided rather easily, however, in order to increase the number of fractions which could be collected without interruption.
Elastic After-Effect in Metals
Authors: Sayre M. F.
Published: January 2006

Lying on the border line between plastic and elastic action in metals and in other solids, there is a group of phenomena which have received a good deal of attention in recent years. On rapidly loading and unloading a rod, a given strain first appears and then as rapidly disappears. This is clearly elastic action. On loading the same rod slightly beyond the yield point and maintaining the load, the elastic component of the strain first appears, very rapidly followed by large additional deformations which do not disappear on unloading. The latter, in a ductile material, clearly represent the result of plastic flow. More accurate observations show that in this second case, the recovery on removal of the load can be separated into two parts, the larger part of the recovery occurring virtually instantaneously on removal of the load, the balance being spread over a long period of time, hours or even days, the rate of recovery decreasing as the time increases.
The Engler Viscometer and the Theory of Laminar Flow at the Entrance of a Tube
Authors: Schiller L.
Published: January 2006

In his lecture at the last meeting of The Society of Rheology Dr. Erk considered the Engler viscometer and pointed out that the relationship between kinematic vicosity ν and Engler degrees E is adequately represented by Vogel's empirical equation ν = E100 {7.6(1−1/E3)}. In contrast, as Dr. Erk also indicated, the theoretical equations of Mises and of the author show appreciable departures from experimental values. With regard to the equation considered by the author as an approximate equation for high viscosities, I have since found that an error was made in its derivation, so that the failure of the equation is not to be ascribed to the theory of laminar entrance-flow. Meanwhile it has been demonstrated that the theory of laminar entrance-flow, as far as one can expect it, actually agrees with observations and with Vogel's equation, as I should like to show you briefly.
Approximate Calibration of Apparatus for Measuring Absolute Viscosity
Authors: Weiss C. H. , Louis M.
Published: January 2006

In calibrating any apparatus adapted to measuring directly the coefficient of absolute viscosity of liquids, the constant must be obtained within certain limits of error. Direct calculation would lead a priori to about 1 per cent for this error. The experiments made up to date show that it is more and that it may be 2 per cent. The authors attribute these additional errors to the great variation of viscosity with temperature of the standard liquids used, and to the uncertainty in maintaining uniformity of temperature in these liquids.

The custom of using only such viscometric apparatus that is capable of giving directly a correct measure of this physical constant is spreading more and more among technologists of the oil industry. More and more often the objection is raised that these instruments are rather delicate in manipulation. The one thing really necessary for transpiration instruments is to have a set of capillary tubes, which assures laminar streaming, the so-called Poiseuille régime, during every determination.

Since it is impossible to construct capillaries of predetermined dimensions, it is necessary to calibrate each tube before releasing it for service.

It is in a course of preliminary experiments toward the establishment of a center for the calibration of viscometrical tubes at the National School for Petroleum at Strasbourg, that we have been led to make the above remarks. We should like to have the opinions of others who have had occasion to do similar work.
Outline of a Systematic Survey of Rheological Theories
Authors: Reiner Markus
Published: January 2006

The theories which have been proposed in order to explain rheological phenomena have increased to such an extent that it is difficult to avoid confusion. Some of these theories appear to be conflicting, although they may be equally correct, each one in its own field. For this reason a systematic survey of rheological theories should be very useful. It should make understanding the different theories more easy and it should assist in assessing to each of them its value in its proper field.
The Flow of Solid Metal Aggregates
Authors: Jenkins C. H. M.
Published: January 2006

The paper discusses the extent and nature of the internal changes in a metal subjected at a suitable temperature to a steady stress sufficiently high to produce flow and rupture. The general strength of metals at high temperatures is compared with that of other metals at atmospheric temperatures. Flow occurs in metallic aggregates by three means which are not necessarily independent, namely, by slip within the crystals, by grain boundary movement, and by continuous recrystallization under stress. The method of ascertaining the rate of creep and estimating significance of the tests are briefly described in relation to the probable mode of flow. The connection between the flow and the previous condition of the metal, i. e., whether cast or worked, etc., is related to the microstructure and grain size. Further factors, such as the action of grain boundary and crystalline material, within the grains are discussed in relation to their effect on intercrystalline rupture and slip. Evidence is given of the importance of these factors by the consideration of a case of an alloy which age-hardens on exposure to service temperatures. Further factors, such as the effect of temperature, are referred to in the concluding portion of the paper.
High-Pressure Capillary Flow
Authors: Hersey Mayo D. , Snyder George H. S.
Published: January 2006

A further development is given in this paper of the theory of the flow of liquids in capillaries under inlet pressures that are high enough to cause an appreciable change in viscosity, such that the viscosity can no longer be treated as uniform. The results are put in the form of Poiseuille's law, with a correction factor. Starting from any given empirical relation between viscosity and pressure, an expression for the corresponding correction factor can be obtained by integration. Conversely, if the form of the function connecting viscosity with pressure is unknown, it can be determined by differentiation of the observed flow-pressure graph connecting rate of flow with inlet pressure. For the usual case it can be shown that the rate of flow approaches an asymptotic limiting value. If for any reason the logarithmic viscosity-pressure diagram takes an upward bend, the viscosity increasing more rapidly than before, the rate of flow must actually decrease with further increase of inlet pressure, and the flow-pressure graph will pass through a maximum. The foregoing analysis makes possible several different methods for computing the viscosity-pressure characteristics of a lubricating oil, or other liquid, from the simple experimental procedure of observing the efflux out of a long metal capillary into the free atmosphere. The paper includes a review of the calculations by S. Kiesskalt for flat capillaries; and indicates under what conditions the extrusion type of high-pressure gage proposed by C. Barus might be realized. The theory is illustrated by the experiments of C. Barus on marine glue to 30,000 pounds per square inch, and by more recent experiments of the authors on pressure-gun and cup grease, and on castor oil, to approximately 45,000 pounds per square inch. The long capillary method is less sensitive and less precise but much more rapid than the two methods previously used in the work of the A. S. M. E. Special Research Committee on Lubrication. From the data presented on castor oil it appears that all three methods are in reasonable agreement.
The Pachimeter as an Instrument for Testing Materials, with Special Reference to Clays, Soils, and Flours
Authors: Scott Blair G. W. , Schofield R. K.
Published: January 2006

In an earlier paper concerning the deforming of plastic materials the distinction has been emphasized between (a) the extent to which a material can be deformed without rupture, and (b) the stress required to cause this deformation to start to take place. The former (a) (which formed the main consideration of the earlier paper) is the plasticity, and the latter (b) is in the nature of a yield-value or shearing strength.
The Viscosity of Potassium Chlorate in Aqueous Solution
Authors: Hood G. Raymond
Published: January 2006

In another connection, the anomalous behavior of very dilute aqueous salt solutions, notably potassium chloride and potassium chlorate, made it of interest to learn the viscosities of these solutions at low concentrations. The viscosity of aqueous KCl has been precisely measured by Joy and Wolfenden, but so far as we have found them, the recorded data on KClO3 proved inadequate for our purpose. The viscosity has therefore been measured in the hope that a study of the variation of this property with the concentration might reveal a relationship enabling us to interpret our results in the prior study.
An Electro-Rheic Effect of a Thixotropic Gel
Authors: Karrer E.
Published: January 2006

Thixotropy (thixein, to smear; tropein, to change) has recently been applied to a phenomenon of gels and sols which really has been known for some time, but whose significance has merely begun to dawn. Some systems will decrease in viscosity when stirred. Such are certain gelatine gels, rubber cements, and certain others as Portland cement. In case of the glycerine and litharge mixtures whose thixotropic properties I am reporting elsewhere, a change from a solid to a very plastic state may be brought about by violent mechanical agitation. These changes in viscosity, hardness, plasticity, and solidity with mechanical agitation are connected with thixotropy. A liquid or a sol whose rate of flow through small tubes is not proportional to the pressure gradient may be said to be thixotropic also. There are many illustrations of this in albumins, celluloses, and suspensions, oils and greases. The phenomenon of thixotropy gives important clues to the nature of the structure of these colloid systems. Such changes immediately suggest analogies to the sensibility of living biological systems to mechanical stimulation. Also after a thixotropic system has been agitated the transformation from the less viscous to the more viscous state has analogy with recovery in living organic systems.
Some Physical Properties of Pure Ricinoleic Acid: The Refractive Index, Specific Gravity, and Viscosity
Authors: André Emile , Vernier Chas.
Published: January 2006

In modifying previous methods for obtaining pure ricinoleic acid, the authors were able to prepare the compound with a degree of purity which had not previously been reached and discovered that very pure sodium ricinoleate may be crystallized from its alcoholic solution.

The authors determined a series of physical properties of pure ricinoleic acid, the specific gravity, refractive index, and viscosity at various temperatures. These determinations make it possible to establish the degree of purity of this chemical species rapidly and certainly, or, on the other hand, to draw comparisons between them and the properties of other fatty acids which would give us more accurate and broader knowledge of their constitution.
An Ancient Problem in Rheology
Authors: Bingham Eugene C.
Published: January 2006

Some of the more leisurely sightseers in the National Capitol make the pilgrimage to the Rock Creek Cemetery not alone to see the Adams monument of Saint Gaudens but to examine the marble tombstone which has become bent during the course of years due to being supported on four posts under the ends but left without support in the middle. The stone is 180 cm long, 90 cm wide and 5 cm thick, and the sagging amounts to some 8 cm. The amount of sag makes any effect due to solution or weathering inadequate as an explanation. That the phenomenon cannot be due to a simple elastic deformation seems equally beyond question, for had the workmen who put the stone in place eighty years ago noted a three inch sag they would undoubtedly have supported the middle part.
Parallel Plate Plastometry
Authors: Peek R. L.
Published: January 2006

The methods employed to determine the deformation under stress of soft solids are largely empirical in character. To evaluate the working properties of materials that are molded or extruded, and the “creep,” “cold flow,” or “plasticity” of materials that yield slowly under load, recourse must be had to comparative tests simulating as closely as possible the conditions to which the material will be subject in service. As service conditions can seldom be exactly duplicated in any practical test, particularly with respect to the time element, these methods always involve some uncertainty as to the validity of the parallel between test and service behavior, and the results are in any case limited in their application. There is, therefore, a need for the development of methods of determining, from simple general tests, the character and amount of deformation under given conditions. While much of the theoretical background for this purpose is available, little progress has been made in applying it to the test methods adapted to materials of the type in question.
Contribution to the Study of Viscous Friction and the Application to the Theory of Lubrication
Authors: Mercier Pierre
Published: January 2006

The author shows briefly:

The origins and the relations of the idea of the dynamic film to the classic results concerning viscosity. How one can pass from one idea to the other, and in the expressions Δu and Δv make the forces tangent and normal to the elements of films appear in the case of movement parallel to a plane.

The introduction and the significance of the curvature φ of rectangular trajectory to the filaments, which comes into the new expressions for Δu and Δv, together with the curvature ψ of the filaments.

The condition of rectangularity between filaments and trajectories gives a relation between ψ and φ and their partial derivatives following these curves. A very simple and new form for the component of the viscous force due to the velocity, with its new notations.

Discussion of results. Experimental study of simple slip—arrangement employed—influence of the proximity of the walls—inadequacy of the classical expressions concerning the forces due to convergence or divergence—plane films with forced uniform motion—schematic picture of actual lubrication in the case of considerable speed of rotation—the zone of crushing (Leslie pressure)—the two zones of viscous acceleration—the surface of zero velocity.

Test of an intrinsic method of rectangular system of coordinates with application to the dynamics of incompressible fluids. Use of the new functions Φ′ = Φ∂s2/∂y; Ψ′ = Ψ∂s1/∂x to define a system of curvilinear coordinates by the curves carries to the axes.

The potential of curvature and the factor of torsion. Representation of the expressions γx and γy.
Contribution to the Study of the Flow of Viscous Liquids
Authors: Camichel C.
Published: January 2006

In the first part, the author recalls the principal phenomena concerning the flow of the viscous liquids about an immersed body when the Reynolds numbers are progressively increased. The following factors in order have been studied in the Laboratory of Hydraulics of Toulouse.

1. Curves (C. CAMICHEL AND P. DUPIN);

2. Pressures about a Submerged Body for Small Reynolds Numbers (E. CRAUSSE AND J. BAUBIAC);

3. Similitude of the Limiting Layer for Small Reynolds Numbers (L. ESCANDE AND M. TEISSIE SOLIER);

4. Anomalies Shown by Colloids for Small Reynolds Numbers (M. PICHOT AND P. DUPIN);

5. Alternating Vortices of Bénard-Karman (P. DUPIN);

6. Secondary Vortices (E. CRAUSSE AND J. BAUBIAC);

7. Surfaces of Discontinuity (L. ESCANDE AND M. TEISSIE SOLIER);

8. Varying Modes of Contraction of Jets at the Entrance of a Nozzle (C. CAMICHEL AND P. DUPIN);

9. Determination of the Vector Vortex at a Determined Work Value for Different Values of the Reynolds Number (C. CAMICHEL AND P. DUPIN);

10. Viscosity of a Liquid Containing Solid Particles in Suspension (J. LHOMME).
The Structural Properties of Anisotropic Solutions of Soap as Determined by a New Centrifugal Falling Ball Method
Authors: McBain James W. , Watts Otto O.
Published: January 2006

Soap solutions are unique in that over a wide range of higher concentrations at temperatures from room temperature up to one or two hundred degrees they are doubly refracting and constitute the only easily accessible examples of liquid crystals. Nevertheless, apart from a few photographs published by McBain and the original curious observations of Lehmann on the double conic shape assumed by free drops of ammonium oleate, no study of their liquid crystalline properties has yet appeared, and not even an approximate measurement of their mechanical properties has been recorded in the literature. It is, therefore, of immediate interest to characterize them as being clear, colorless, faintly opalescent, anisotropic liquids whose apparent viscosity is several hundred times greater than that of vaseline at room temperatures. For these reasons we have begun the systematic investigation of their properties.
Viscosity Problems in Igneous Rocks
Authors: Balk Robert
Published: January 2006

The earth's magma, a siliceous melt which is believed to underlie the entire solid crust of the earth, is, in all probability, a highly viscous liquid. Wherever molten lava is observed in motion, either in craters of volcanoes (Kilauea, Mauna Loa, Hawaii), or as disastrous flows which descend volcanic mountains (Vesuvius, Mount Aetna, etc.), or in the vicinity of volcanic fissures (Laki, Eldgja rift, Iceland) it behaves like a liquid of appreciable viscosity; the degree of viscosity, however, varies, depending on the proportion of admixed gases and water vapor, and the chemical composition of the lava. Lavas rich in silica are highly viscous (rhyolite, dacite), while those rich in iron and magnesium (basalt, andesite) are more fluid. The viscosity of every lava flow increases until the melt slowly freezes, because of the chilling effect of the surface temperatures on the earth.
A Further Study of Association by the Fluidity Method
Authors: Bingham Eugene C. , DeTurck Harold L.
Published: January 2006

The paper of Bingham and Fornwalt showed the need for fluidities of additional pure associated liquids. This paper is intended to supply that need particularly in the group of esters. The substances employed were obtained from the Eastman Kodak Company, but before use they were dehydrated with calcium chloride and distilled, the middle fraction being measured. Viscometer 1–23 and pyenometer 1–29 were used. The data on the fluidities and specific volumes are given in Tables I to XVII. The fluidity curves are nearly linear, and from the curves were read the temperatures required to give a certain desired fluidity, as, for example, 200 rhes. The atomic temperatures of Bingham and Spooner were used to calculate these temperatures, and the ratio of these two values gave the association n. These values are given in Table XVIII.
A Method for Determining Diffusion Constants of Colloids which Show Mechanical Birefringence
Authors: Boeder Paul
Published: January 2006

Experimental investigations of Freundlich, Zocher, and others have shown that birefringence induced by flow in colloids arises from the tendency of nonspherical particles to orientate under the mechanical stresses within the fluid.
The Mechanics of Plastic Deformation: The Flow of Duralumin through Orifices
Authors: Goubkin S. I.
Published: January 2006

At the present stage of the metal-working industry the treatment of metals by pressure is one of the most important technological processes. Further development of technique will, no doubt, only increase the significance of this process. It must be stated, however, that the working of metals by pressure has as yet no strictly scientific basis. The theory of the mechanics of the plastic deformation of bodies, on which the working of metals by pressure is based, finds itself in the initial phase of its development and is far from being in a state where we can guide ourselves by it directly in our industrial work.
Cosmological Magnetic Field: A Fossil of Density Perturbations in the Early Universe
Authors: Ichiki Kiyotomo , Takahashi Keitaro , Ohno Hiroshi , Hanayama Hidekazu , Sugiyama Naoshi
Published: January 2006

The origin of the substantial magnetic fields that are found in galaxies and on even larger scales, such as in clusters of galaxies, is yet unclear. If the second-order couplings between photons and electrons are considered, then cosmological density fluctuations, which explain the large-scale structure of the universe, can also produce magnetic fields on cosmological scales before the epoch of recombination. By evaluating the power spectrum of these cosmological magnetic fields on a range of scales, we show here that magnetic fields of 10
–18.1
gauss are generated at a 1-megaparsec scale and can be even stronger at smaller scales (10
–14.1
gauss at 10 kiloparsecs). These fields are large enough to seed magnetic fields in galaxies and may therefore have affected primordial star formation in the early universe.
The Orbital Period of the Ultraluminous X-ray Source in M82
Authors: Kaaret Philip , Simet Melanie G. , Lang Cornelia C.
Published: January 2006

The ultraluminous x-ray source (ULX) in the galaxy M82 has been identified as a possible intermediate-mass black hole formed in stellar collisions in the super star cluster MGG 11. The x-ray flux from M82 is modulated, with a peak-to-peak amplitude corresponding to an isotropic luminosity of 2.4 _ 1040 erg s‐1 in M82 and a period of 62.0 � 2.5 days, which we interpret as the orbital period of the ULX binary. This orbital period implies that the mass-donor star must be a giant or supergiant. Large mass-transfer rates, sufficient to fuel the ULX, are expected for a giant-phase mass donor in an x-ray binary. The giant phase has a short lifetime, indicating that we see the ULX in M82 in a brief and unusual period of its evolution.
Early Maya Writing at San Bartolo, Guatemala
Authors: Saturno William A. , Stuart David , Beltrán Boris
Published: January 2006

The ruins of San Bartolo, Guatemala, contain a sample of Maya hieroglyphic writing dating to the Late Preclassic period (400 B.C. to 200 A.D.). The writing appears on preserved painted walls and plaster fragments buried within the pyramidal structure known as “Las Pinturas,” which was constructed in discrete phases over several centuries. Samples of carbonized wood that are closely associated with the writing have calibrated radiocarbon dates of 200 to 300 B.C. This early Maya writing implies that a developed Maya writing system was in use centuries earlier than previously thought, approximating a time when we see the earliest scripts elsewhere in Mesoamerica.
Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk
Authors: Donato D. C. , Fontaine J. B. , Campbell J. L. , Robinson W. D. , Kauffman J. B. , Law B. E.
Published: January 2006

We present data from a study of early conifer regeneration and fuel loads after the 2002 Biscuit Fire, Oregon, USA, with and without postfire logging. Natural conifer regeneration was abundant after the high-severity fire. Postfire logging reduced median regeneration density by 71%, significantly increased downed woody fuels, and thus increased short-term fire risk. Additional reduction of fuels is necessary for effective mitigation of fire risk. Postfire logging can be counterproductive to the goals of forest regenration and fuel reduction.
Cholera Toxin Indirectly Activates Human Monocyte-Derived Dendritic Cells In Vitro through the Production of Soluble Factors, Including Prostaglandin E2and Nitric Oxide
Authors: Bagley Kenneth C. , Abdelwahab Sayed F. , Tuskan Robert G. , Lewis George K.
Published: January 2006

Cholera toxin (CT) is a potent adjuvant that activates dendritic cells (DC) by increasing intracellular cyclic AMP (cAMP) levels. In vivo and in vitro, very small amounts of CT induce potent adjuvant effects and activate DC. We hypothesized that DC intoxicated by CT may release factors that enhance their own maturation and induce the maturation of toxin-free bystander DC. Through the use of mixed cultures and transwell cultures, we found that human monocyte-derived DC (MDDC) pulsed with CT or other cAMP-elevating agonists induce the maturation of bystander DC. Many DC agonists including CT increase the production of prostaglandin E2(PGE2) and nitric oxide (NO). For this reason, we determined whether the actions of PGE2or NO are involved in the maturation of MDDC induced by CT or dibutyryl-cAMP (d-cAMP). We found that blocking the production of PGE2or blocking prostaglandin receptors inhibited MDDC maturation induced by CT and d-cAMP. Likewise, sequestering NO or blocking the downstream actions of NO resulted in the inhibition of MDDC maturation induced by CT and d-cAMP. These results indicate that endogenously produced factors including PGE2and NO contribute to the maturation of DC induced by CT and that these factors participate in bystander DC maturation. The results of this study may help explain why bacterial toxins that elevate cAMP are such potent adjuvants.
Mycoplasma suisAntigens Recognized during Humoral Immune Response in Experimentally Infected Pigs
Authors: Hoelzle L. E. , Hoelzle K. , Ritzmann M. , Heinritzi K. , Wittenbrink M. M.
Published: January 2006

Today, serodiagnostic tests forMycoplasma suisinfections in pigs have low accuracies. The development of novel serodiagnostic strategies requires a detailed analysis of the humoral immune response elicited byM. suisand, in particular, the identification of antigenic proteins of the agent. For this study, indirect enzyme-linked immunosorbent assay (ELISA) and immunoblot analyses were performed using pre- and sequential postinoculation sera fromM. suis-infected and mock-infected control pigs.M. suispurified from porcine blood served as the antigen. EightM. suis-specific antigens (p33, p40, p45, p57, p61, p70, p73, and p83) were identified as targets of the immunoglobulin G (IgG) antibody response during experimental infection, with p40, p45, and p70 being the preferentially recognizedM. suisantigens. Besides theM. suis-specific antigens, porcine immunoglobulins were identified in blood-derivedM. suispreparations. By immunoglobulin depletion, the specificity of theM. suisantigen for use in indirect ELISA was significantly improved.M. suis-specific Western blot and ELISA reactions were observed in all infected pigs by 14 days postinfection at the latest and until week 14, the end of the experiments. During acute clinical attacks of eperythrozoonosis, a derailment of the antibody response, determined by decreases in both theM. suisnet ELISA values and the numbers ofM. suis-specific immunoblot bands, was accompanied by peaking levels of autoreactive IgG antibodies. In conclusion, theM. suis-specific antigens found to stimulate specific IgG antibodies are potentially useful for the development of novel serodiagnostic tests.
Longitudinal Analysis of
Cryptosporidium
Species-Specific Immunoglobulin G Antibody Responses in Peruvian Children
Authors: Priest Jeffrey W. , Bern Caryn , Xiao Lihua , Roberts Jacquelin M. , Kwon James P. , Lescano Andres G. , Checkley William , Cabrera Lilia , Moss Delynn M. , Arrowood Michael J. , Sterling Charles R. , Gilman Robert H. , Lammie Patrick J.
Published: January 2006

Cryptosporidium
species are ubiquitous in the environment and are frequently detected in the stools of children who live where sanitation conditions are poor. To better characterize the immune response to these parasites, we monitored immunoglobulin G (IgG) antibody levels in a cohort of children from Lima, Peru. Two new enzyme-linked immunosorbent assays based on the
C. parvum
(bovine, subtype IIa) Iowa strain 17-kDa and 27-kDa antigens were used to measure IgG antibody levels in longitudinal serum samples. Antibody responses were detected during infections with
C. parvum
,
C. felis
, and
C. meleagridis
and with four different subtypes of
C. hominis
. We also noted that the magnitude of the antibody response was related to the number of previous infections and that older children generally had higher levels of antibodies to the two
C. parvum
antigens. Antibody responses were not associated with infections with either
Cyclospora
sp. or
Giardia
sp. We believe the antibody assays will be important tools for monitoring the success of future public health interventions.
Epithelial Toll-Like Receptor 5 Is Constitutively Localized in the Mouse Cecum and Exhibits Distinctive Down-Regulation during Experimental Colitis
Authors: Ortega-Cava Cesar F. , Ishihara Shunji , Rumi Mohammad A. K. , Aziz M. M. , Kazumori Hideaki , Yuki Takafumi , Mishima Yoshiyuki , Moriyama Ichiro , Kadota Chikara , Oshima Naoki , Amano Yuji , Kadowaki Yasunori , Ishimura Norihisa , Kinoshita Yoshikazu
Published: January 2006

We recently demonstrated that the pattern recognition receptors (PRRs) toll-like receptor 2 (TLR2), TLR4, and CD14 are expressed in mouse colonic epithelium in a compartmentalized manner. Here we report the localization of TLR5, the receptor for bacterial flagellin, and its distinctive down-regulation during experimental colitis. Guts from normal BALB/c mice and those with dextran sodium sulfate (DSS)-induced colitis were compared. Each gut was divided into seven segments (stomach, small intestine [three parts], and colon [three parts]), and epithelial cells and crypt units were collected by scraping and EDTA treatment, respectively. Northern blotting showed that TLR5 mRNA was preferentially expressed in the epithelium of the proximal colon in normal mice. Laser capture microdissection coupled to reverse transcriptase PCR confirmed this localization. TLR5 protein expression reflected mRNA expression, as evidenced by Western blotting. In mice with acute colitis, inflammation occurred mainly in the distal colon. Interestingly, while TLR2, TLR4, and CD14 were up-regulated in the inflamed colon, TLR5 was down-regulated at both the mRNA and protein levels. Decreased TLR5 expression was more evident during chronic colitis. Additional in vitro studies using a mouse cell line, Colon-26, showed that gamma interferon (IFN-γ) time- and dose-dependently down-regulates TLR5. In conclusion, epithelial cells, mainly in the proximal colon, constitutively express TLR5. TLR5 expression is down-regulated in vivo during acute and chronic DSS-induced colitis, in contrast to the expression of TLR2, TLR4, and CD14. The mechanism governing TLR5 regulation may therefore differ from that controlling other PRRs. Finally, IFN-γ may be involved in down-regulating TLR5 expression.
Multilocus Sequence Types, Serotypes, and Variants of the Surface Antigen PspA in
Streptococcus pneumoniae
Isolates from Meningitis Patients in Poland
Authors: Sadowy Ewa , Skoczyñska Anna , Fiett Janusz , Gniadkowski Marek , Hryniewicz Waleria
Published: January 2006

Meningitis caused by
Streptococcus pneumoniae
represents an important factor of morbidity and mortality in humans. In a significant number of cases, this disease is associated with specific clones of the organism, the so-called invasive pneumococcal clones. The aim of the study was to analyze 156
S. pneumoniae
isolates identified as etiological agents of meningitis in Poland in the years 1997 through 2002. The isolates were characterized by multilocus sequence typing (MLST), and the results were compared with those obtained by pulsed-field gel electrophoresis (PFGE) and with the MLST data on invasive pneumococci from other countries. Eighty-nine different sequence types were found in the group of isolates, 50 of which had been known before including 19 of the major invasive clones. However, a significant fraction of the isolates possessed novel combinations of known and new MLST alleles. The majority of penicillin-nonsusceptible isolates belonged to the group of international multiresistant clones (Spain
23F
-1, Spain
6B
-2, Spain
9V
-3, Poland
23F
-16, and Poland
6B
-20), which underlined the importance of these in the dissemination of antimicrobial resistance. The results of the MLST analysis correlated well with the PFGE data, thus again demonstrating good congruence between the two typing methods for
S. pneumoniae
. The majority of the isolates (95.5%) belonged to families 1 or 2 of the surface protein PspA, confirming its potential usefulness as the vaccine antigen candidate.
Reverse Line Blot Assay for Direct Identification of Seven
Streptococcus agalactiae
Major Surface Protein Antigen Genes
Authors: Zhao Zuotao , Kong Fanrong , Gilbert Gwendolyn L.
Published: January 2006

We developed a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB) to detect the genes encoding members of the family of variable surface-localized proteins of
Streptococcus agalactiae
(group B streptococcus [GBS]), namely, Bca (Cα), Rib, Epsilon (Epsilon/Alp1/Alp5), Alp2, Alp3, and Alp4, and the immunoglobulin A binding protein, Bac (Cβ). We used the assay to identify these genes in a collection of well-characterized GBS isolates and reference strains. The results showed that mPCR/RLB avoids the common problems of cross-reaction and nontypability associated with protein typing using antisera. It is as sensitive as, but more practical than, separate gene-specific PCRs and would be suitable for large molecular epidemiological studies of GBS.
Evaluation of the INOVA Diagnostics Enzyme-Linked Immunosorbent Assay Kits for Measuring Serum Immunoglobulin G (IgG) and IgA to Deamidated Gliadin Peptides
Authors: Prince Harry E.
Published: January 2006

New assays for antibodies to deamidated gliadin peptides (DGP) expressing celiac disease-specific epitopes were evaluated using 154 sera previously tested for endomysial immunoglobulin A (IgA) (EMA), transglutaminase IgA (TGA), and conventional gliadin antibodies. DGP antibody results showed 97% concordance with EMA and TGA results. Of 56 sera negative for EMA and TGA but positive for conventional gliadin antibodies, 54 (96%) were negative for DGP antibodies.
Human Endotoxemia Induces Down-Regulation of Monocyte CC Chemokine Receptor 2
Authors: Heesen Michael , Renckens Rosemarijn , de Vos Alex F. , Kunz Dagmar , van der Poll Tom
Published: January 2006

Upon injection ofEscherichia colilipopolysaccharide into human volunteers, the monocyte density of CC chemokine receptor 2 (CCR2) decreased. Minimal CCR2 density was observed 4 h after injection. Peak plasma concentrations of the CCR2 ligand monocyte chemotactic protein 1 and of tumor necrosis factor alpha were reached after 4 h and 2 h, respectively.
Neutralizing and Hemagglutination-Inhibiting Activities of Antibodies Elicited by the 2004-2005 Influenza Vaccine against Drifted Viruses
Authors: Ansaldi Filippo , Bacilieri Sabrina , Banfi Federica , Durando Paolo , Sticchi Laura , Icardi Giancarlo , Gasparini Roberto
Published: January 2006

Evaluation of the antibody responses induced by the 2004-2005 influenza vaccine strain against the homologous variant, the 2004-2005 field isolates, and a previous circulating strain showed that a correlation between neutralizing and hemagglutination-inhibiting activities exists only when the antigen is very close to the vaccine strain.
Interleukin-6 Promotes Anti-OspA Borreliacidal Antibody Production In Vitro
Authors: Munson Erik L. , Nardelli Dean T. , Luk K. H. Kevin , Remington Monica C. , Callister Steven M. , Schell Ronald F.
Published: January 2006

Determination of the immunological mediators responsible for promoting the production of borreliacidal antibody may facilitate the development of an improved borreliosis vaccine for human and veterinary use. Previously, we developed an in vitro assay to determine if borreliacidal antibody production could be augmented by treatment with different cytokines. In this study, in vitro treatment of lymph node cells producing borreliacidal antibody with recombinant interleukin-6 (rIL-6) resulted in a fourfold enhancement of anti-OspA borreliacidal antibody. Moreover, rIL-6 enhanced Western immunoblot titers and increased the number of B lymphocytes. In contrast, treatment of anti-OspA borreliacidal antibody-producing cells with anti-IL-6 resulted in a fourfold reduction in borreliacidal activity. Treatment with anti-IL-6 also inhibited enhanced borreliacidal antibody production induced by anti-gamma interferon. These data suggest that IL-6 plays a significant role in the production of anti-OspA borreliacidal antibodies.
Cellular Immune Responses in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1) Infection and Effects of Vaccination with Recombinant Envelope Glycoprotein ofHIV-1
Authors: Gorse Geoffrey J. , Simionescu Ramona E. , Patel Gira B.
Published: January 2006

Effects of human immunodeficiency virus type 1 (HIV-1) recombinant envelope glycoprotein vaccines on cell-mediated immune (CMI) responses were assessed in HIV-1-infected patients. Asymptomatic, antiretroviral-treatment-naïve, HIV-1-infected patients with CD4+T-cell counts greater than 400/μl received multiple intramuscular injections of HIV-1 IIIB recombinant envelope glycoprotein (rgp160) vaccine or HIV-1 MN recombinant envelope glycoprotein (rgp120) vaccine (eight patients, referred to as the HIV-1 vaccinees) or placebo or hepatitis B vaccine (three patients, referred to as the controls). Lymphocyte proliferation in response to HIV-1 envelope glycoproteins, both homologous and heterologous to the HIV-1 immunogens, was absent prior to study treatment in all patients but increased significantly during the vaccination series and after the final vaccination in HIV-1 vaccinees (P< 0.05) and remained absent in control patients. In flow cytometric analyses of intracellular cytokines, T-cell receptor stimulation with an anti-CD3 antibody induced gamma interferon (IFN-γ) expression by activated CD4+and CD8+lymphocytes at greater frequencies than did stimulation with recombinant envelope glycoprotein and p24 of HIV-1 (P< 0.05). Mean frequencies of HIV-1 envelope glycoprotein-stimulated, activated intracellularIFN-γ-producing CD4+and CD8+lymphocytes and of interleukin-2-producing CD4+lymphocytes did not increase after vaccination, but cytokine-producing cells were detectable in some patients. Comparing pre- to post-HIV-1 vaccination time points, changes in frequencies of activated, IFN-γ-producing CD4+cells correlated inversely with changes in lymphocyte proliferation in response to recombinant envelope glycoprotein in HIV-1 vaccinees (P< 0.05). Increased CMI responses to HIV-1 envelope glycoprotein measured by lymphocyte proliferation were associated with HIV-1 recombinant envelope glycoprotein vaccines.
Immunoglobulin G Avidity in Differentiation between Early and Late Antibody Responses to West Nile Virus
Authors: Fox Janet L. , Hazell Stuart L. , Tobler Leslie H. , Busch Michael P.
Published: January 2006

In 1999 West Nile virus (WNV) surfaced in the United States in the city of New York and spread over successive summers to most of the continental United States, Canada, and Mexico. Because WNV immunoglobulin M (IgM) antibodies have been shown to persist for up to 1 year, residents in areas of endemicity can have persistent WNV IgM antibodies that are unrelated to a current illness with which they present. We present data on the use of IgG avidity testing for the resolution of conflicting data arising from the testing of serum or plasma for antibodies to WNV. Thirteen seroconversion panels, each consisting of a minimum of four samples, were used. All samples were tested for the presence of WNV IgM and IgG antibodies, and the avidity index for the WNV IgG-positive samples was calculated. Panels that exhibited a rise in the WNV IgM level followed by a sequential rise in the WNV IgG level were designated “primary.” Panels that exhibited a marked rise in the WNV IgG level followed by a sequential weak WNV IgM response and that had serological evidence of a prior flavivirus infection were designated “secondary.” All samples from the “primary” panels exhibited low avidity indices (less than 40%) for the first 20 to 30 days after the recovery of the index sample (the sample found to be virus positive). All of the “secondary” samples had elevated WNV IgG levels with avidity indices of ≥55%, regardless of the number of days since the recovery of the index sample. These data demonstrate that it is possible to differentiate between recent and past exposure to WNV or another flavivirus through the measurement of WNV IgG avidity indices.
Simultaneous Detection of Antibodies to Six Nonhuman-Primate Viruses by Multiplex Microbead Immunoassay
Authors: Khan Imran H. , Mendoza Sara , Yee JoAnn , Deane Matthew , Venkateswaran Kodumudi , Zhou Shan S. , Barry Peter A. , Lerche Nicholas W. , Luciw Paul A.
Published: January 2006

To maintain healthy nonhuman primates for use in biomedical research, animals are routinely screened for several infectious agents at most facilities. Commonly, monkey serum samples are tested by conventional immunoassays, such as enzyme-linked immunosorbent assays (ELISAs) or Western blotting, for antibodies to specific infectious agents. For testing for antibodies against multiple agents in each sample, conventional immunoassays are laborious and time-consuming. More efficient immunoassays are needed. Accordingly, we have developed a novel multiplex serodiagnostic system based on individually identifiable, fluorescent microbead sets, where each bead set is coated with antigens from a purified preparation of a specific virus. The coated bead sets are mixed to enable the detection of antibodies to multiple viruses in one serum or plasma sample. These viruses include four agents that are routinely tested for maintenance of specific-pathogen-free monkeys, namely, simian immunodeficiency virus, simian type D retrovirus, simian T-cell lymphotropic virus, and herpes B virus, as well as simian foamy virus and rhesus cytomegalovirus, both of which are commonly found in nonhuman primates. This multiplex microbead immunoassay (MMIA) enabled the simultaneous detection of antibodies to all six viruses in single serum samples as small as 1 microliter. The results obtained by MMIA analysis correlated with results of conventional ELISAs, which detect antibodies to single agents. Thus, this multiplex microbead detection system is an efficient diagnostic modality for serosurveillance of nonhuman primates.
Comparison of a New ESAT-6/CFP-10 Peptide-Based Gamma Interferon Assay and a Tuberculin Skin Test for Tuberculosis Screening in a Moderate-Risk Population
Authors: Porsa Emaeil , Cheng Lee , Seale Michael M. , Delclos George L. , Ma Xin , Reich Robert , Musser James M. , Graviss Edward A.
Published: January 2006

Screening for latent tuberculosis infection (LTBI) with Mantoux tuberculin skin test (TST) has many limitations, including false-positive results due to exposure to
Mycobacterium
other than tuberculosis (TB) and BCG vaccination. A total of 474 adult inmates in a county jail were screened for LTBI using TST and a new ESAT-6/CFP-10 peptide-based whole-blood gamma interferon (IFN-γ) assay. LTBI prevalence was 9.0 and 5.4% as determined by TST and IFN-γ assay, respectively. Overall, agreement between test results was 90% (
κ =
0.25). Positive TST results were significantly associated with increased age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01 to 1.08), African-American ethnicity (OR, 4.97; 95% CI, 1.58 to 15.68), foreign birth (OR, 20.20; 95% CI, 4.21 to 97.02) and prior incarceration (OR, 6.19; 95% CI, 1.48 to 25.95). Positive IFN-γ assay results were significantly associated with African-American ethnicity (OR, 5.58; 95% CI, 1.16 to 26.74). Factors associated with statistically significant discordance between TST and IFN-γ assay results were African-American ethnicity (OR, 0.29; 95% CI, 0.11 to 0.77), foreign birth (OR, 0.23; 95% CI, 0.07-0.80), and prior incarceration (OR, 0.06; 95% CI, 0.01-0.50). Among subjects born in the United States, African-American ethnicity was the only variable significantly associated with positive test results for both TST (OR, 4.26; 95% CI, 1.38 to 13.16) and IFN-γ assay (OR, 5.74; 95% CI, 1.19 to 27.75) and remained associated with statistically significant discordance between TST and IFN-γ assay results. The reactivity of the new IFN-γ assay is unaffected by prior BCG vaccination or serial TSTs but may be diminished in African-Americans. Future longitudinal studies are needed to assess the sensitivity and specificity of this new assay in detecting LTBI.
Recombinant Multiepitope Protein for Early Detection of Dengue Infections
Authors: AnandaRao Ravulapalli , Swaminathan Sathyamangalam , Fernando Sirimali , Jana Asha M. , Khanna Navin
Published: January 2006

Dengue fever is a mosquito-borne viral disease prevalent mainly in tropical countries. As the clinical manifestations of dengue are not very unique, laboratory diagnosis is crucial in identifying cases of dengue infection. Detection of dengue infection based on the identification of antidengue antibodies has emerged as a practical and reliable means of diagnosing dengue fever. We recently developed a customized recombinant dengue multiepitope protein (r-DME-G) that can specifically detect the immunoglobulin G (IgG) class of antidengue antibodies in patient sera. Using this strategy, we have now created another dengue multiepitope protein, r-DME-M, with specificity for the IgM class of antidengue antibodies. A synthetic gene encoding the r-DME-M protein was expressed as a maltose-binding protein fusion in
Escherichia coli
. The recombinant protein was purified in a single affinity chromatographic step to obtain yields of ∼15 mg purified protein/liter of culture. The purified protein was used to develop an in-house IgM enzyme-linked immunosorbent assay (ELISA) and tested using a panel of 172 patient sera characterized using the commercially available Dengue Duo rapid strip test from PanBio, Australia. The IgM ELISA results showed that the r-DME-M protein not only recognized all IgM
+
samples identified by the PanBio test but also identified samples missed by the latter test. We also successfully adapted the r-DME-M protein to a rapid strip test format. This approach of creating customized antigens coupled to overexpression in
E. coli
and simple purification offers a promising alternative option to dengue diagnosis with the potential to circumvent the drawbacks of the whole virus antigen-based commercial kits.