bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoluminescence and resonant Raman scattering from ZnO-opal structures
Authors: Ursaki V. V. , Tiginyanu I. M. , Zalamai V. V. , Masalov V. M. , Samarov E. N. , Emelchenko G. A. , Briones F.
Published: June 2004

We study photoluminescence (PL) of ZnO-opal structures excited by a 351.1 nm laser line. The structures were fabricated by infiltration of ZnO from an aqueous solution of zinc nitrate into opal matrices. The emission spectrum of thick ZnO layers grown on the surface of bulk opals exhibits narrow PL bands associated with the recombination of bound and free-excitons. The free-exciton lines are discussed taking into account the polariton phenomena. The width of the excitonic lines (2–3 meV) along with their energy position is indicative of high quality and strain-free state of the layer. The emission from ZnO crystallites embedded into bulk opal is dominated by near band gap luminescence, a weak quantum confinement effect being observed for crystallites with sizes around 50 nm. Thin ZnO films grown on single-layer opals exhibit enhanced resonant Raman scattering, phonon confinement effects, and surface-related modes. Strong exciton-LO phonon and exciton-Fröhlich mode coupling in ZnO nanostructures is deduced from the analysis of multiphonon excitonic resonant Raman scattering.
The role of dimers in evaporation of small argon clusters
Authors: Napari Ismo , Vehkamäki Hanna
Published: June 2004

Evaporation of small Lennard-Jones argon clusters has been studied using molecular dynamic simulations. An extensive library of clusters with 4, 5, 6, 11, and 21 atoms has been obtained from an earlier study. Analysis of the evaporation properties of the clusters indicate, that the fraction of dimer evaporations of all evaporation events increases with the total energy of the cluster. The fraction of evaporated dimers from clusters with a constant lifetime is independent of the cluster size for short-lived clusters and increases with cluster size for long-lived clusters. Only a few percent of the clusters which are long lived enough to participate in vapor–liquid nucleation decay by emitting dimers. The mean cluster lifetime as a function of total energy shows the same exponentially decreasing trend for monomer and dimer evaporation channels. The fraction of trimer evaporations is found to be vanishingly small.
Overcritical state in superconducting round wires sheathed by iron
Authors: Pan Alexey V. , Dou Shixue
Published: June 2004

Magnetic measurements carried out on MgB2 superconducting round wires have shown that the critical current density Jc(Ba) in wires sheathed by iron can be significantly higher than that in the same bare (unsheathed) wires over a wide applied magnetic field Ba range. The magnetic behavior is, however, strongly dependent on the magnetic history of the sheathed wires, as well as on the wire orientation with respect to the direction of the applied field. The behavior observed can be explained by magnetic interaction between the soft magnetic sheath and superconducting core, which can result in a redistribution of supercurrents in the flux filled superconductor. A phenomenological model explaining the observed behavior is proposed.
Low frequency noise and long-term stability of noncoherent light sources
Authors: Rumyantsev S. L. , Shur M. S. , Bilenko Yu. , Kosterin P. V. , Salzberg B. M.
Published: June 2004

Low frequency fluctuations in light intensity were measured from five different types of commercially available light emitting diodes with wavelengths from 375 nm to 740 nm and from two different halogen lamps. At low frequencies below 10–100 Hz some light emitting diodes (LEDs) can provide lower levels of noise than halogen lamps. A noise quality factor β is proposed in order to characterize noise behavior of LEDs.
Temperature-dependent optical properties of B-doped nc-Si:H thin films in the interband region
Authors: Chen H. , Shen W. Z.
Published: June 2004

We report on the thermal effects on optical properties in a B-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin film grown by plasma enhanced chemical vapor deposition, using optical transmission measurements from 10 to 300 K. It is demonstrated that reliable band gaps and optical constants can be deduced by the employment of Forouhi and Bloomer’s dielectric function model [Phys. Rev. B 34, 7018 (1986)] in the interband region, which overcomes the underestimation of the optical band gaps. We have obtained temperature dependence of optical band gaps, absorption coefficient, and refractive index in B-doped nc-Si:H, and discussed the results within the framework of electron-phonon interactions. These optical properties provide an experimental basis for further device design of nc-Si:H.
Quantum state and screening effects on electron-hydrogen polarization bremsstrahlung in partially ionized plasmas
Authors: Jung Young-Dae
Published: June 2004

The polarization bremsstrahlung radiation due to electron-neutral atom scatterings in partially ionized hydrogen plasmas is investigated. A screened polarization potential model is applied to describe the polarization interaction between the projectile electron and the neutral target atom. The classical trajectory analysis is applied to represent the polarization bremsstrahlung radiation cross section as a function of the impact parameter, Debye length, radiation photon energy, and collision energy. The results show that the plasma screening effects on the bremsstrahlung cross section are found to be more significant for the soft photon radiation. It is also found that the bremsstrahlung radiation cross section is significantly increased with the increasing quantum state.
Rhenium, an in situ pressure calibrant for internally heated diamond anvil cells
Authors: Zha Chang-Sheng , Bassett William A. , Shim Sang-Heon
Published: June 2004

The rheologic, chemical, thermal, and electrical properties of rhenium make it an excellent choice for containing and heating samples to very high pressures and temperatures in diamond anvil cells (DACs). In many experimental configurations, e.g., the internally heated diamond anvil cell (IHDAC), the rhenium parts are at or close to the pressure and temperature conditions of the sample. Because the pressure and temperature of the rhenium container are close to those of the specimen, rhenium offers an attractive means for determining pressure at high temperatures in x-ray diffraction experiments without the requirement of adding an additional material to the intricate and cluttered sample assembly. For this reason, we set out to determine an equation of state (EOS) of rhenium. We combine the isothermal equation of state of rhenium at ambient temperature with volume data collected at randomly distributed, simultaneous high pressure-temperature conditions. A linear dependence of thermal pressure on temperature at constant volume has been assumed. Data were collected using synchrotron radiation x-ray diffraction in conjunction with an IHDAC equipped with a rhenium internal resistive heater developed recently at the Cornell High Energy Synchrotron Source. The consistency over a large P–T range between our EOS and shock EOS within the experimental uncertainty suggests that the thermal pressure is measurable using the method proposed in the article, and that the rhenium can be used as a convenient pressure calibrant although the accuracy of it depends on many factors including the reliability of the pressure scale at high temperature.
Complete genomes of two clinical
Staphylococcus aureus
strains: Evidence for the rapid evolution of virulence and drug resistance
Authors: Holden Matthew T. G. , Feil Edward J. , Lindsay Jodi A. , Peacock Sharon J. , Day Nicholas P. J. , Enright Mark C. , Foster Tim J. , Moore Catrin E. , Hurst Laurence , Atkin Rebecca , Barron Andrew , Bason Nathalie , Bentley Stephen D. , Chillingworth Carol , Chillingworth Tracey , Churcher Carol , Clark Louise , Corton Craig , Cronin Ann , Doggett Jon , Dowd Linda , Feltwell Theresa , Hance Zahra , Harris Barbara , Hauser Heidi , Holroyd Simon , Jagels Kay , James Keith D. , Lennard Nicola , Line Alexandra , Mayes Rebecca , Moule Sharon , Mungall Karen , Ormond Douglas , Quail Michael A. , Rabbinowitsch Ester , Rutherford Kim , Sanders Mandy , Sharp Sarah , Simmonds Mark , Stevens Kim , Whitehead Sally , Barrell Bart G. , Spratt Brian G. , Parkhill Julian
Published: June 2004

Staphylococcus aureus
is an important nosocomial and community-acquired pathogen. Its genetic plasticity has facilitated the evolution of many virulent and drug-resistant strains, presenting a major and constantly changing clinical challenge. We sequenced the ≈2.8-Mbp genomes of two disease-causing
S. aureus
strains isolated from distinct clinical settings: a recent hospital-acquired representative of the epidemic methicillin-resistant
S. aureus
EMRSA-16 clone (MRSA252), a clinically important and globally prevalent lineage; and a representative of an invasive community-acquired methicillin-susceptible
S. aureus
clone (MSSA476). A comparative-genomics approach was used to explore the mechanisms of evolution of clinically important
S. aureus
genomes and to identify regions affecting virulence and drug resistance. The genome sequences of MRSA252 and MSSA476 have a well conserved core region but differ markedly in their accessory genetic elements. MRSA252 is the most genetically diverse
S. aureus
strain sequenced to date: ≈6% of the genome is novel compared with other published genomes, and it contains several unique genetic elements. MSSA476 is methicillin-susceptible, but it contains a novel Staphylococcal chromosomal cassette (SCC)
mec
-like element (designated SCC
476
), which is integrated at the same site on the chromosome as SCC
mec
elements in MRSA strains but encodes a putative fusidic acid resistance protein. The crucial role that accessory elements play in the rapid evolution of
S. aureus
is clearly illustrated by comparing the MSSA476 genome with that of an extremely closely related MRSA community-acquired strain; the differential distribution of large mobile elements carrying virulence and drug-resistance determinants may be responsible for the clinically important phenotypic differences in these strains.
U.S.-Uzbek Partnership and Democratic Reforms
Authors: Akbarzadeh Shahram
Published: June 2004

In March 2002 the United States and Uzbekistan signed a Declaration of Strategic Partnership. This document marked a qualitative break in the international relations of Uzbekistan and, to some degree, the United States' relations with Central Asia. Uzbekistan had sought closer relations with the United States since its independence in September 1991. But the course of U.S.-Uzbek relations was not smooth. Various obstacles hindered Tashkent's progress in making a positive impression on successive U.S. administrations in the last decade of the twentieth century. Tashkent's abysmal human rights record and the snail's pace of democratic reforms made the notion of closer ties with Uzbekistan unsavoury for U.S. policy makers. At the same time, Washington was more concerned with developments in Russia. Other former Soviet republics, especially the five Central Asian states, were relegated to the periphery of the U.S. strategic outlook. But the dramatic events of September 11 and the subsequent U.S.-led “war on terror” changed the geopolitical landscape of Central Asia. The consequent development of ties between Tashkent and Washington was beyond the wildest dreams of Uzbek foreign policy makers. Virtually overnight, Uzbek leaders found themselves in a position to pursue an ambitious foreign policy without being slowed by domestic considerations.
The Political Significance of Cultural Nationalism: The Slavophiles and Their Notion of a Russian Enlightenment
Authors: Rabow-Edling Susanna
Published: June 2004

For nearly a century, the contrast between a cultural and a political form of nationalism has been upheld. In the early twentieth century, Fredrich Meinecke made a distinction between the political nation, orStaatsnation, based on a common political history and a shared constitution, and the cultural nation,Kulturnation, based on a shared cultural heritage. The most important distinction between the two is that while membership in the former is voluntary, membership in the cultural nation is a matter not of choice, but of common objective identity. Meinecke maintained that political nationalism derived from the spirit of 1789,i.e. from the idea of the self-determination and sovereignty of the nation. Cultural nationalism, in contrast, was a striving for national individuality, characteristic of anti-Enlightenment German thought.
Fetal alcohol syndrome through the eyes of parents
Authors: DeVries Jocie , Waller Ann
Published: June 2004

Although fetal alcohol syndrome (FAS) was first identified by research scientists in the USA in 1973, it was not until 1989 when an adoptive parent, Michael Dorris, wrote The Broken Cord, that a practical description of the disability came into public awareness. Within the next 2 years, parents of children diagnosed with this disability teemed up with interested professionals to organize the FAS Family Resource Institute (FAS*FRI). This educational non‐profit organization has now devoted over a decade to their mission to identify, understand and care for individuals with fetal alcohol syndrome/effects (FAS/E) and to prevent this disability from occurring in future generations. Their mission has necessitated the identification of a behavioral phenotype for FAS/E, the development of a professional training curriculum, and operation of a national family advocacy and mentoring network. By adding their own families' experiences to the information gathered from thousands of other families with diagnosed children, they have accumulated enough experiential, frontline reports which are similar enough to serve as their research science base.
Paternal contribution to fetal alcohol syndrome
Authors: Abel Ernest
Published: June 2004

Maternal alcohol use during pregnancy is associated with a wide range of adverse outcomes for the child. Many women who drink during pregnancy also have male partners who abuse alcohol. Existing data on paternal effects of alcohol abuse during the preconceptual period and at the time of conception are reviewed. Epidemiological data offer some support for a paternal influence on birth weight, congenital heart defects, and some evidence of mild cognitive impairments. Animal data have demonstrated decreased litter size, increased prevalence of low birth weight fetuses and mixed data on risk of malformations. Increased susceptibility to Pseudomonas bacterial infection has been reported. Cognitive and behavioral findings are the most robust effects. These include learning and memory deficits, hyperactivity, and poor stress tolerance. Multiple causal mechanisms for a paternal effect have been suggested, but none seems satisfactory to explain all findings. Further research is needed on paternal effects in animals and human populations. The results of this research may influence prevention activities.
The challenge of fetal alcohol syndrome in the criminal legal system
Authors: Fast Diane , Conry Julianne
Published: June 2004

People with fetal alcohol spectrum disorder (FASD) present challenges to those who work in the criminal legal system. Prenatal exposure to alcohol can cause physical, neurological, and psychological impairments. It is vital to understand the individual offender in order to address the underlying reasons for criminal behavior. Individuals with FASD often come from dysfunctional backgrounds, and may have mental illnesses and substance use disorders. A comprehensive medical ‐ legal report, prepared by a professional experienced with FASD, can help judges and lawyers understand how complex the interactions are among brain damage, genetics, and the environment. The person with FASD can be misunderstood in court, victimized in jails, and mismanaged in the transition back to the community, unless those working with the individual are aware of FASD and its implications.
THE RELEASE OF SPECIFIC BACTERICIDAL ANTIBODIES BY ENDOTOXIN
Authors: Michael J. Gabriel
Published: June 2004

Studies presented in this report are concerned with the effect of endotoxin upon the release of bactericidal antibodies as determined by the agar plaque technique. We found that shortly after the injection of mice with small amounts of endotoxin the number of plaque-forming cells in the spleen was substantially reduced and remained low for about 12 hr. At the same time the titer of specific bactericidal antibodies in the circulation was increased, 6-mercaptopurine was shown to be an effective suppressor of the immune response by inhibiting the multiplication of bactericidin-forming cells. However, administration of this drug did not modify the initial responses of antibodies and plaque-forming cells to endotoxin. Thus, we postulate that endotoxin does not induce destruction and subsequent reconstitution of bactericidin-forming cells, but that the observed changes represent a release of preformed antibodies from competent cells. For a limited time, thereafter, these cells become inactive, but soon resume their normal function of releasing bactericidal antibodies.
AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM FUNICULOSUM
Authors: Shope Richard E.
Published: June 2004

1. Helenine injected intraperitoneally 24 hr prior to a regularly fatal dose of Semliki Forest virus saves most of the mice to which it is administered.

2. Mice saved by helenine develop no viral immunity and regularly succumb when rechallenged 2 wk later with the same dose of virus from which they were originally saved.

3. The time during which helenine is optimally effective in protecting mice from death by Semliki Forest virus covers a period of approximately 36 hr beginning after about 12 hr and extending to 48 hr before virus infection. When periods of less than 12 hr, or more than 48 hr, elapse between the time of helenine administration and virus inoculation, its protective effectiveness diminishes progressively.

4. Repeated injections of helenine at 2- or 3-day intervals, if continued long enough, exhaust the capacity of a host to respond favorably to helenine administered 24 hr before virus inoculation.

5. Helenine injections at intervals of 4, 3, and 2 wk before its administration 24 hr prior to infection do not decrease the effectiveness of this final dose in protecting mice from fatal infection by the virus.

The experimental results here reported indicate that, as suggested by the findings of earlier work, helenine does not act directly as an antiviral substance, but instead exerts its effect through some substance that it induces the host to elaborate. The nature of this induced antiviral substance is as yet unknown though, to judge from the failure of spared mice to acquire viral immunity, it appears to act at a stage in viral replication prior to that at which antigenic viral protein is produced.

The findings with helenine and those thus far reported for interferon afford no factual basis for judging the relationship of the two, if any.
IMMUNOCHEMICAL STUDY OF ANTIGENIC SPECIFICITY IN DELAYED HYPERSENSITIVITY
Authors: Leskowitz Sidney , Jones Valerie E. , Zak Soloman J.
Published: June 2004

Hapten-specific delayed hypersensitivity was produced by immunization of guinea pigs with arsanilic acid conjugated to N-acetyltyrosine or other small aromatic molecules. Such hapten-specific delayed sensitivity could be passively transferred by peritoneal exudate cells. While a conjugate made from a polymer of D-amino acids was ineffective in producing sensitization, the conjugate made with D-tyrosine was effective, suggesting that the inability of D-amino acid polymers to be broken down by enzymes might be bypassed by use of the monomer. The effectiveness of such monomers in producing delayed sensitivity, but not antibody production, is consistent with a hypothesis that different types of antigenic determinants are involved in the production of each.
THE EFFECT OF HYDROCORTISONE AND X-IRRADIATION ON THE LYMPHOCYTOSIS INDUCED BY BORDETELLA PERTUSSIS
Authors: Morse Stephen I.
Published: June 2004

1. In mice rendered lymphocytopenic by X-irradiation or hydrocortisone acetate, pertussis vaccine evoked both lymphocytosis and polymorphonuclear leukocytosis.

2. When mice with lymphocytosis induced by pertussis vaccine were X-irradiated, prompt and extensive destruction of circulating as well as tissue small lymphocytes occurred. The devitalized circulating cells were cleared from the blood primarily by the Kupffer's cells of the hepatic sinusoids.

3. Hydrocortisone acetate administered to mice with lymphocytosis did not cause acute lymphopenia nor was there any evidence of destruction of circulating small lymphocytes. However, destruction of these cells within lymphoid tissues was apparent. These observations suggested that adrenal cortical hormones are not "lymphocytolytic" with respect to circulating lymphocytes.
THE INFLUENCE OF CORTISONE ON EXPERIMENTAL VIRAL INFECTION
Authors: Smart K. Marilyn , Kilbourne Edwin D.
Published: June 2004

A comparative study was undertaken of the pathogenesis of infection of the allantoic sac of the chick embryo with three influenza viruses of differing virulence, and of the influence of hydrocortisone on the course of infection.

Judged on the basis of earlier onset and greater degree of inflammatory response and diminished survival time of infected embryos, Mel. and Lee viruses were markedly more virulent than PR8, despite the earlier appearance of virus in PR8-infected embryos. Interferon appeared first and in greater quantity in the allantoic fluid of Lee-infected embryos and latest with PR8 infection. Thus, there was no correlation of avirulence and better interferon production with the viruses under study in the present system. Furthermore, evidence obtained suggested that Lee virus ("virulent") was most susceptible to interferon action, and also that viral synthesis in the chorioallantoic membrane with PR8 ("avirulent") persisted after the appearance of interferon.

The injection of hydrocortisone within 2 hr of the initiation of infection delayed the synthesis of all three viruses; had no significant effect upon the inflammatory response; and transiently inhibited the synthesis of interferon, while prolonging the survival of Lee- and Mel.-infected embryos. Late administration of hydrocortisone suppresses both the inflammatory response and the production of interferon.

Only in the case of Lee virus infection did hydrocortisone administration lead to augmentation of final yields of virus with the low infection multiplicity employed in the present experiments. It is postulated that Lee virus is a better inducer of interferon because its infectivity in vivo is more rapidly inactivated. As a consequence synthesis of Lee virus is more under the control of endogenous interferon than is the case with PR8 or Mel. virus. Therefore, inhibition of interferon synthesis with hydrocortisone has a greater influence on final yields of Lee virus.
FURTHER STUDIES OF INFECTIOUS DNA EXTRACTED FROM MYCOBACTERIOPHAGES
Authors: Sellers Margret I. , Tokunaga Tohru
Published: June 2004

Results of the previous investigation in which it was found that DNA extracted from D29 mycobacteriophage was infectious for Mycobacterium smegmatis 607, have been extended. DNA extracted from mycobacteriophage D4 and D32 produced plaques when plated on their respective hosts; D28 DNA, extracted in the same manner and tested under similar conditions, failed to show infectivity. Species barriers were not crossed by mycobacteriophage DNA; bacteria resistant to intact phage were not infected with the phage DNA. The efficiency of plating of the DNA is very much lower than that of intact phage; infection of a given host was not accomplished by DNA when titration for plaque formation by the intact phage was less than 109 PFU.

The base composition of DNA extracted from the four mycobacteriophages and the three propagating hosts was very similar. The bases were paired, adenine with thymine and guanine with cytosine. A relatively higher per cent of guanine-cytosine than of adenine-thymine, was found. The buoyant density of each DNA in CsCl was linearly related to its guanine-cytosine content whereas with the exception of D28 DNA, thermal denaturation temperatures failed to show this relationship. However, the thermal transition profiles were characteristic of double stranded DNA.

Additional evidence that D29 DNA forms complexes with basic proteins was obtained. Binding between calf thymus histone and between RNAase and D29 DNA readily occurs with a resultant loss in DNA infectivity. Trypsin and D29 DNA are only weakly reactive.
ELEVATED γ-GLOBULIN AND INCREASED ANTIBODY PRODUCTION IN MICE INFECTED WITH LACTIC DEHYDROGENASE VIRUS
Authors: Notkins Abner Louis , Mergenhagen Stephan E. , Rizzo Anthony A. , Scheele Christina , Waldmann Thomas A.
Published: June 2004

Infection of mice with the lactic dehydrogenase virus (LDV) resulted in an elevated level of γ-globulin. Histologic examination of the spleen and lymph nodes revealed that the number of germinal centers was greatly increased. Immunization with human γ-globulin showed that the capacity of the virus-infected animal to produce anti-human γ-globulin was greatly enhanced and that the virus acted as an adjuvant. From these experiments it is concluded that a virus infection (LDV) can affect the immunologic response of the host to a heterologous antigen.
THE LIVER AS THE SITE OF C-REACTIVE PROTEIN FORMATION
Authors: Hurlimann J. , Thorbecke G. J. , Hochwald G. M.
Published: June 2004

The site of formation of C-reactive protein (CxRP, CRP) has been studied with tissues from rabbits, monkeys, and human beings. Rabbits and monkeys were stimulated to produce the acute phase protein by injection of turpentine, croton oil, endotoxin, paratyphoid-typhoid vaccine, or pneumococci. C14-amino acid incorporation in vitro was demonstrated by means of autoradiography of immunoelectrophoretic patterns made with culture fluids.

It was found that among many different tissues tested liver was the only tissue which incorporated C14-lysine and isoleucine into CxRP or CRP. Only livers taken 16 to 24 hr after various stimuli were active; livers from normal animals or from animals killed 3 to 9 hr after stimulation did not produce detectable amounts of CxRP. Inflamed muscle from the injection site did not show C14-amino acid incorporation into CxRP. Several human tissues were also cultured, and a few liver cultures found to contain labeled CRP.

The formation of CxRP or CRP by the liver was always accompanied by enhanced C14-amino acid incorporation into other serum proteins, but the reverse was not always found.
ISOLATED FECAL MICROORGANISMS CAPABLE OF 7 α-DEHYDROXYLATING BILE ACIDS
Authors: Gustafsson Bengt E. , Midtvedt Tore , Norman Arne
Published: June 2004

Strains of microorganisms capable of 7α-dehydroxylation of chenodeoxycholate were isolated from rat and human feces. All the strains were strictly anaerobic, non-motile, moderately themioresistant Gram-positive rods. They showed some saccharolytic properties with the production of both acid and gas. They were H2S-positive but indole-, skatole-, citrate-, catalase-, and oxidase-negative.

The isolated strains capable of 7α-dehydroxylation of chenodeoxycholate were also able to oxidize the hydroxyl groups at C-3 and C-7 to keto groups. The following metabolites were isolated: 3-keto-7α-hydroxy-5ß-cholanoic acid, 3α-hydroxy-7-keto-5ß-cholanoic acid, 3α-hydroxy-5ß-cholanoic acid, and 3-keto-5ß-cholanoic acid. The isolated strains did not have the enzymes necessary for hydrolyzing conjugated bile acids.

In mixed anaerobic cultures of fecal microorganisms, extensive reduction of the 3-keto group to the 3ß-hydroxyl group occurred. The microorganism(s) responsible for this reaction have as yet not been isolated.
RELEASE OF KALLIKREIN FROM GUINEA PIG LUNG DURING ANAPHYLAXIS
Authors: Jonasson O. , Becker E. L.
Published: June 2004

An antigen-antibody reaction occurring in the perfused sensitized guinea pig lung, has been demonstrated to release kallikrein, a proteolytic enzyme related to the formation of kinins. This lung kallikrein is similar to plasma kallikrein in all properties studied, including susceptibility to the same inhibitors, electrophoretic mobility, and heterogeneity in molecular size.

The release of kallikrein during anaphylaxis in the guinea pig lung occurs in the presence of ethylenediaminetetraacetate. Perfusion of ellagic acid into nonsensitized lungs will also release kallikrein, presumably through activation of Hageman factor. On the basis of these findings the hypothesis is suggested that the kallikrein in perfused lung activated by the antigen-antibody reaction is, in fact, plasma kallikrein. It is further suggested that activation of such kallikrein by the antigen-antibody reaction proceeds through Hageman factor.
THE RENAL LESION ASSOCIATED WITH HEMOGLOBINEMIA
Authors: Jaenike John R.
Published: June 2004

A method is presented for the production of a reproducible and reversible renal lesion in the rat by the intravenous injection of a relatively small amount of homologous hemoglobin (40 mg/100 g body weight). Production of the lesion is dependent on prior water deprivation and its severity is related to the degree of dehydration. Ether anesthesia, at the time of hemoglobin injection, predisposes to a severe and reproducible functional defect in the dehydrated rat. In contrast, injection of hemoglobin during pentobarbital anesthesia results in a significant lesion only sporadically. The functional evolution of the lesion has been characterized by inulin clearance measurements. Functional impairment occurs abruptly, within 1 hr after hemoglobin injection, and persists unchanged over the ensuing several hours. Some increase in inulin clearance rate is usually observed at 24 hr after injection, but severe functional impairment persists. Between 24 and 72 hr, a considerable increase in inulin clearance rate occurs, so that only moderate restriction of excretory function is present at the latter time. A further moderate increase in inulin clearance rate is apparent at 7 days after hemoglobin injection, but some reduction in function. persisted in all rats studied at this time.

Hemoglobinuria is slight or inapparent in animals manifesting the most marked depression of excretory function, indicating that a severe renal lesion may exist in the absence of visible urinary pigment. Hemoglobinemia is evanescent at the dosage used in this study. These observations suggest that clinical acute renal failure secondary to hemoglobinemia may readily go unrecognized and that this may be a more frequent association than is now appreciated.
STUDIES ON THE EFFECT OF THE CARRIER MOLECULE ON ANTIHAPTEN ANTIBODY SYNTHESIS
Authors: Siskind Gregory W. , Paul William E. , Benacerraf Baruj
Published: June 2004

1. Fluorescence quenching has been calibrated, by comparison with equilibrium dialysis, for measurement of antibody-hapten association constants with guinea pig antibody to the 2,4-dinitrophenyl (DNP) determinant. The maximum quenching with all sites occupied which gave best agreement with equilibrium dialysis was found to be 100%.

2. The carrier to which the DNP-hapten is coupled influences significantly the amount, class (γ1 or γ2), and affinity of the antibody of DNP specificity made by individual guinea pigs.

3. The affinities of γ1- and γ2-antibodies from individual guinea pigs are generally very similar.

4. Precipitin curves with γ1-antibodies show more marked inhibition of precipitation in antigen excess than do precipitin curves with the less charged γ2-antibodies, indicating the importance of nonspecific forces in the precipitation reactions.
THE IN VITRO DIFFERENTIATION OF MONONUCLEAR PHAGOCYTES
Authors: Cohn Zanvil A. , Fedorko Martha E. , Hirsch James G.
Published: June 2004

A combined morphological, autoradiographic, and cytochemical study at the electron microscope level has been directed towards the formation of electron-opaque granules of cultured macrophages.

Labeling of the membrane-bound vesicular structures of pinocytic origin was accomplished with colloidal gold. The initial uptake of gold occurred within micropinocytic vesicles. These electron-lucent vesicles subsequently fused with and discharged their contents into larger pinocytic vacuoles. Colloidal gold was homogeneously distributed in the large pinosomes. In contrast, gold was initially deposited in the periphery of preformed dense granules indicating that these structures were also in constant interaction with the external environment.

Colloidal gold was not observed within the cisternae of the endoplasmic reticulum nor within the saccules or vesicles of the Golgi apparatus. There were, however, many small, gold-free vesicles, indistinguishable from Golgi vesicles, which were preferentially aligned about and appeared to fuse with the large pinosomes.

The intracellular flow of leucine-H3-labeled protein was followed by electron microscopic autoradiography. After a 15 min pulse of labeled amino acid there was initial labeling of the rough endoplasmic reticulum. Subsequently, much of the label appeared in the Golgi complex. At still later time periods the cytoplasmic dense granules contained the majority of the isotope.

Acid phosphatase activity was localized to the dense granules and in the majority of cells to the Golgi apparatus.

It is suggested that hydrolytic enzymes are initially synthesized in the endoplasmic reticulum and are then transferred to the Golgi apparatus. Here they are packaged into small Golgi vesicles which represent the primary lysosome of macrophages. The Golgi vesicles subsequently fuse with pinosomes, thereby discharging their hydrolases and forming digestive granules or secondary lysosomes.
REAGINIC ACTIVITY ASSOCIATED WITH IGG IMMUNOGLOBULIN
Authors: Reid Robert T. , Minden Percy , Farr Richard S.
Published: June 2004

Five human sera with reaginic activity to a number of allergens were fractionated using anion exchange chromatography. In each serum, fractions which contained detectable IgG and no detectable IgA had capacity to fix to skin and subsequently elicit a P-K reaction. Four of these sera had reaginic activity about equally distributed between fractions containing only IgG and fractions containing mixtures of IgG and IgA. A fifth serum contained reaginic activity to crystalline bovine serum albumin (BSA) and most of the activity was associated with the fraction which contained only IgG. This serum was extensively studied using a variety of techniques and it was confirmed that most of the reagin to BSA in this serum was in those fractions containing only IgG. Since reaginic activity can no longer be considered a unique property of IgA the implications of finding antibody with reaginic qualities in immunoglobulins other than IgA are discussed.
ANTIBODY PRODUCTION BY CELLS IN TISSUE CULTURE
Authors: Bussard Alain E. , Hannoun Claude
Published: June 2004

By combining a tissue culture method with the detection of antibody-producing cells by local hemolysis in gum it has been possible to follow the immunological activity of cells from tissue fragments for long period of time.

These fragments were obtained from lymph nodes or spleens of rabbits immunized by sheep erythrocytes.

It was found that, while the immunological activity of the free cells in suspensions decreased fast and disappeared in a few days, the cells attaching on glass could express their activity for at least 3 wk. It is assumed that these cells are the daughters of cells from the fragments which were not active antibody producers at the beginning, but differentiated, during the culture, into cells endowed with two capacities: glass adherence and antibody synthesis.

One can further admit that the type of culture employed exerts a selective pressure favoring formation of antibody-producing cells.
CHARACTERIZATION OF THE RENIN-ANTIRENIN SYSTEM
Authors: Warren Bert , Johnson Arthur G. , Hoobler S. W.
Published: June 2004

Rabbit antibody capable of neutralizing the pressor activity of the enzyme renin, derived from hog kidneys, was characterized with respect to type and capacity to react serologically. Three antirenin antibodies were detected, both a precipitating and nonprecipitating, neutralizing antibody as well as a neutralizing antibody capable of being absorbed by inactivated renin. The precipitating, neutralizing antibody was purified and used successfully in an assay for hog renin by means of a hemagglutination inhibition test. By immunofluorescent methods utilizing the purified antiserum, renin was found to be localized in the macula densa of the distal convoluted tubules and the juxtaglomerular cells of the afferent arteriole in both hog and dog kidneys.
IMMUNE LYSIS OF NORMAL HUMAN AND PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PNH) RED BLOOD CELLS
Authors: Rosse Wendell F. , Dourmashkin Robert , Humphrey John H.
Published: June 2004

1. The defects produced on the membrane of the human red blood cell by the action of complement and antibody have been studied by the use of the electron microscope. These are round to slightly ovoid holes and are surrounded by an irregular ring, about 20 A thick. The mean diameter of the holes is about 103 A if human complement is used (regardless of the antibody used for sensitization) and about 88 A if guinea pig complement is used.

2. The holes in normal and PNH red cells appear to be identical, under the same conditions. The membrane defects produced by lysis of PNH cells with acidified normal serum (the Ham's test) are identical to those produced by complement lysis with specific antibody, indicating that complement is undoubtedly the cause of such lysis.

3. Evidence is presented that when human complement acts on human red cells sensitized with anti-I antibody, each complete activation of complement leads to the production of a cluster of holes. This contrasts to the action of guinea pig complement, on sheep cells, each activation of which leads to a single hole.

4. The maximum number of anti-I antibody molecules which can attach to a human red cell (i.e. the minimum number of antigen sites) is about 500,000 for both normal and PNH cells.

5. The number of holes produced during lysis of the PNH cell is the same as that of the normal cell. When all cells are lysed by am excess of C', a mean of about 90,000 holes are present on each membrane. When complement is limited, a larger proportion of PNH cells are lysed due to their peculiar sensitivity to C' but the number of holes on each lysed cell is the same as for normal cells lysed by the same concentration of C'.
STUDIES ON THE IN VIVO AND IN VITRO MULTIPLICATION OF THE LDH VIRUS OF MICE
Authors: du Buy Herman G. , Johnson Martin L.
Published: June 2004

In vivo analysis of the virus titer in various loci, 24 hr after infection, showed that a titer similar to that in the blood plasma was found in the ascitic fluid of Erlich ascites cancer-bearing mice, and in lymph nodes, spleen, and thymus, i.e. loci which contain macrophages as a common cell type. However, only in the lymph nodes and in the ascitic fluid did the increase in virus titer precede or parallel the increase in the plasma.

The LDH virus titer in the plasma of X-irradiated mice was similar to that of control mice, eliminating radiation-sensitive cells but not macrophages as target cells of the virus.

Electron microscopic observation of infected lymph node cells revealed the presence of two types of particles: one consisting of small densely stained annuli, about 25 mµ in diameter and one of similar dense annuli with a halo extending the diameter to about 50 mµ. Such particles were repeatedly observed within single or double membraned vesicles.

In vitro, the LDH virus multiplied only in cultures of mouse peritoneal macrophages, maintained in medium 199 with 10% FBS. The virus titer could be maintained for at least 33 days, during eleven serial passages, involving an overall dilution factor of 1011. These results corroborate the findings of Evans and Salaman, who used peritoneal macrophages maintained in Eagle's medium and 5 to 10% lamb serum. However, in the serial passage experiments reported here, the virus titer could only be maintained following trypsinization of each successive inoculum. The role of macrophages as the target cell for LDH virus multiplication in vivo is discussed.
THE IN VIVO FORMATION AND FATE OF ANTIGEN-ANTIBODY COMPLEXES FORMED BY FRAGMENTS AND POLYPEPTIDE CHAINS OF RABBIT γG-ANTIBODIES
Authors: Spiegelberg Hans L. , Weigle William O.
Published: June 2004

The in vivo formation and subsequent fate of complexes formed between specific rabbit γG-antibody subunits and circulating protein antigens was studied in rabbits and guinea pigs. Subunits obtained from purified antibodies were injected immediately after an injection of antigen, and the elimination from the circulation of either I*-labeled γG-subunits or labeled antigen determined.

In the absence of antigen, all γG-subunits which lack the Fc fragment were rapidly eliminated. In the presence of excess antigen, F (ab')2, Fab and Fd fragments reacted with antigen and remained in the circulation as complexes which were eliminated at the same rate as the antigen. Fab hybrids containing a specific Fd fragment and a nonspecific L chain similarly reacted with antigen and remained in the circulation complexed to antigen. In contrast, L chains and Fab hybrids containing a specific L chain and a nonspecific Fd fragment did not react with antigen in vivo and were rapidly eliminated in both presence and absence of antigen. H chains remained in the circulation of rabbits in the absence of antigen, however, in the presence of antigen, more H chains which formed complexes with antigen remained in the intravascular space and were rapidly eliminated when the immune elimination of the antigen by the host occurred. Nonspecific H chains were rapidly eliminated from the circulaion of guinea pigs, whereas specific H chains remained in the circulation with the antigen.

F (ab')2 fragments formed complexes with antigen near antibody equivalence and in antibody excess which were rapidly eliminated, however, less effectively than complexes formed near antibody equivalence with intact γG. Complexes formed in antibody excess between Fab fragments and H chains remained in the circulation at all concentrations studied and were eliminated at the rate of antigen.

The role of the Fc fragment in the immune elimination of antigen-antibody complexes is discussed.
CONGENITAL INFECTIONS WITH REOVIRUS
Authors: Hashimi Ali , Carruthers Mary M. , Wolf Paul , Lerner A. Martin
Published: June 2004

Congenital reovirus, type 2 infections were produced after intraperitoneal inoculations of brood mothers on the 1st, 3rd, 6th, 10th, and 15th day of gestation. The offspring presented with a varied syndrome. About a quarter of a total of over 200 mice showed symptoms within the first 14 days of life; namely, lassitude, retarded growth, and roughening of fur. Some died, apparently of respiratory or renal failure. Post mortem examination showed marked interstitial pneumonia and subcortical renal tubular necrosis. Reovirus was isolated in high titer from the kidney and lungs as well as from blood, hearts, hind limbs, and brains in lesser titer.

At 3 wk of age over 50 apparently well mice were sacrificed, and virologic, serologic, and pathologic study was done. High titers of virus were again found in the kidney, lung, blood, brain, heart, and skeletal muscle, but all tissues appeared normal histologically. Type-specific serum antibody titers in these mice were approximately those of their mothers.

Another half of these mice showed decreased spontaneous activity and growth retardation which appeared between the 15th and 36th days of life. Three of these mice with late illnesses had marked proptosis and conjunctivitis. A subepidermal conjunctival and extraocular muscle lymphocytic infiltrate was observed on section, and reovirus was isolated from these eyes in tissue culture. Again blood, brain, kidney, liver, spleen, myocardium, and skeletal muscle were studied, and were found to be normal histologically and not to contain reovirus. Finally, the rest of the mice remain well to date.

At 3 months of age, 10 of them were sacrificed. All had lost their maternal antibody and contained no reovirus, type 2 hemagglutinating inhibiting antibodies.

No developmental abnormalities were observed.

These data suggest that prolonged reovirus infections may be established by means of congenital inoculation of the developing fetus. Tolerant infection with immune paralysis seems to have been established.
ROLE OF THE THYMUS IN TOLERANCE
Authors: Staples Parker J. , Gery Igal , Waksman Byron H.
Published: June 2004

Rats subjected to high doses of whole-body irradiation, with simultaneous shielding of the thymus or spleen, recovered at 3 wk the ability to develop delayed sensitization and to form hemagglutinating and precipitating antibody following foot-pad injection of BγG in complete adjuvant. Injection of BγG into the shielded thymus immediately after irradiation, in amounts between 20 γg and 40 mg, inhibited these response to later challenge partially or completely. A comparable effect on immune responses to BγG was not seen after injection of heterologous antigen (Ea) intrathymically, BγG intraperitoneally, or BγG into the shielded spleen. However high doses (20 or 40 mg) of antigen given by the latter routes resulted in some diminution of later response. Arthus reactivity recovered partially in the spleen-shielded group and was readily suppressed by intrasplenic administration of antigen.
AN EXAMINATION OF THE CYTOTOXIC EFFECTS OF SILICA ON MACROPHAGES
Authors: Allison A. C. , Harington J. S. , Birbeck M.
Published: June 2004

Effects of silica, diamond dust, and carrageenan on mouse macrophages were studied by phase-contrast cine-micrography, electron microscopy, histochemical techniques for lysosomal enzymes and measurements of the release of lysosomal enzymes into the culture medium.

All added materials were rapidly taken up into phagosomes, to which lysosomes became attached. In all cases lysosomal enzymes were discharged into the phagosomes to form secondary lysosomes. Within 24 hr most of the silica particles and enzyme had escaped from the secondary lysosomes and lysosomal enzymes were found in the culture media. Most macrophages were killed by this time. With nontoxic particles (diamond dust, aluminium-coated silica, or silica in the presence of the protective agent polyvinyl-pyridine-N-oxide, PVPNO) ingested particles and lysosomal enzymes were retained within the secondary lysosomes for a much longer time, and cytotoxic effects were considerably delayed or absent altogether.

It is concluded that silica particles are toxic because they are efficiently taken up by macrophages and can then react relatively rapidly with the membranes surrounding the secondary lysosomes. The particles and lytic enzymes can then escape into the cytoplasm, producing general damage, and thence into the culture medium. It is suggested that hydrogen bonding of silicic acid with lipid and protein constituents of the membrane accounts for the induced permeability. Protective agents such as PVPNO are retamed in lysosomes and preferentially form hydrogen bonds with silicic acid.

Carrageenan is demonstrable within macrophages by its metachromatic reaction. It brings about release of enzymes from secondary lysosomes, but much more slowly than does silica. Silica released from killed macrophages is as cytotoxic as the original preparation. It is suggested that repeated cycles of macrophage killing in vivo leads to the mobilization of fibroblasts and fibrogenesis characterizing the disease silicosis.