bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic manipulation of the gap in Bi
2
Sr
2
CaCu
2
O
8+x
Authors: Massee F. , Huang Y. K. , Aprili M.
Published: January 2020

Manipulating the gap

Cuprate superconductors typically have a large amount of spatial inhomogeneity, partly stemming from the inhomogeneity of the chemical doping process. In particular, the size of the spectroscopic gap can vary widely across a single sample. Massee
et al.
used the tip of a scanning tunneling microscope to manipulate atoms on the surface of a member of the Bi
2
Sr
2
CaCu
2
O
8+x
cuprate family. Moving bismuth atoms up or down caused adjacent atoms to shift laterally, leading to reversible local changes in the size of the gap. It is expected that the technique can be used to probe the influence of the local lattice on the electronic states of other correlated materials.

Science
, this issue p.
68
Protein-coding changes preceded cis-regulatory gains in a newly evolved transcription circuit
Authors: Britton Candace S. , Sorrells Trevor R. , Johnson Alexander D.
Published: January 2020

Generating a new transcriptional network

Organismal novelties result from changes in transcriptional circuits. But what comes first, changes in regulatory protein or changes in cis-regulatory sequences? Britton
et al.
examine the Matα2 protein in a Saccharomycotina clade of fungi. They show that a newly evolved transcription circuit involving repression of the a-specific genes by the ancient homeodomain protein Matα2 occurred in two stages separated by millions of years. In the first stage, Matα2 acquired several coding changes followed by changes in cis-regulatory sequences. This clade-specific requirement explains how the coding changes of Matα2 were in place long before the new a-specific gene repression circuit arose.

Science
, this issue p.
96
Absence of evidence for chiral Majorana modes in quantum anomalous Hall-superconductor devices
Authors: Kayyalha Morteza , Xiao Di , Zhang Ruoxi , Shin Jaeho , Jiang Jue , Wang Fei , Zhao Yi-Fan , Xiao Run , Zhang Ling , Fijalkowski Kajetan M. , Mandal Pankaj , Winnerlein Martin , Gould Charles , Li Qi , Molenkamp Laurens W. , Chan Moses H. W. , Samarth Nitin , Chang Cui-Zu
Published: January 2020

Looking for chiral Majoranas

Chiral Majorana modes have been predicted to exist in heterostructures consisting of a quantum anomalous Hall insulator and a superconductor. Kayyalha
et al.
fabricated more than 30 such samples and used transport measurements to look for signatures of the Majorana modes. The data indicated that the transport signatures previously thought to be associated with Majorana physics could, in their samples, be explained using a more mundane mechanism.

Science
, this issue p.
64
An RNA vaccine drives expansion and efficacy of claudin-CAR-T cells against solid tumors
Authors: Reinhard Katharina , Rengstl Benjamin , Oehm Petra , Michel Kristina , Billmeier Arne , Hayduk Nina , Klein Oliver , Kuna Kathrin , Ouchan Yasmina , Wöll Stefan , Christ Elmar , Weber David , Suchan Martin , Bukur Thomas , Birtel Matthias , Jahndel Veronika , Mroz Karolina , Hobohm Kathleen , Kranz Lena , Diken Mustafa , Kühlcke Klaus , Türeci Özlem , Sahin Ugur
Published: January 2020

A one-two, CAR-T cell punch

Chimeric antigen receptor (CAR)–T cells have been clinically effective in killing certain hematological malignancies, but achieving long-term patient responses for solid tumors remains a challenge. Reinhard
et al.
describe a two-part “CARVac” strategy to overcome poor CAR-T cell stimulation and responses in vivo. They introduce the tight junction protein claudin 6 (CLDN6) as a new CAR-T cell target and designed a nanoparticulate RNA vaccine encoding a chimeric receptor directed toward CLDN6. This lipoplex RNA vaccine promotes CLDN6 expression on the surface of dendritic cells, which in turn stimulates and enhances the efficacy of CLDN6-CAR-T cells for improved tumor therapy.

Science
, this issue p.
446
Uncovering the ART of antimalarial resistance
Authors: Marapana Danushka , Cowman Alan F.
Published: January 2020

A key mechanism of resistance to the antimalarial drug artemisinin is identified
Difference in Strain Pathogenicity of Septicemic Yersinia pestis Infection in a TLR2
−/−
Mouse Model
Authors: O’Donnell Kyle L. , Knopick Peter L. , Larsen Riley , Sarkar Sanghita , Nilles Matthew L. , Bradley David S.
Published: January 2020

Yersinia pestis
is the causative agent of bubonic, pneumonic, and septicemic plague. We demonstrate that Toll-like receptor 2-deficient (TLR2
−/−
) mice are resistant to septicemic infection by the KIM5 strain of
Y. pestis
but not to infection by the CO92
Δpgm
strain. This resistance is dependent on TLR2, the route of infection, and the isoform of YopJ.
Function of H
2
O
2
, Myeloperoxidase, and Hexose Monophosphate Shunt Enzymes in Phagocytizing Cells from Different Species
Authors: Paul B. B. , Strauss R. R. , Jacobs A. A. , Sbarra A. J.
Published: January 2020

The effect of phagocytosis on the H
2
O
2
production and myeloperoxidase (MPO) activities of leukocytes from various species was investigated. The intracellular distribution of MPO, reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase (6PGDH) of resting and phagocytizing guinea pig polymorphonuclear leukocytes has also been studied. Phagocytizing cells produce more H
2
O
2
than the corresponding resting cells. This has been found to be true for human peripheral polymorphonuclear leukocytes, mouse peritoneal macrophage, and guinea pig and rat peritoneal polymorphonuclear leukocytes. All of these cells, except rabbit alveolar macrophages, have significant MPO activity. Generally an increased activity is noted with phagocytizing cells. Homogenization and differential centrifugation of guinea pig peritoneal polymorphonuclear leukocytes indicate that the whole homogenate and its fractions from phagocytizing cells have significantly higher MPO and NADPH oxidase activities, when compared to the corresponding fractions from the resting cells. The 27,000 ×
g
supernatant fluid from phagocytizing cells has 6-fold more MPO and 2.5-fold more NADPH oxidase activity than similar supernatant fractions from resting cells. The enzyme 6PGDH was unaffected by phagocytosis. The relationship of these stimulated activities to the intracellular bactericidal function of the phagocytes has been discussed.
Effects of
Listeria monocytogenes
Hemolysin on Phagocytic Cells and Lysosomes
Authors: Kingdon G. Charles , Sword C. P.
Published: January 2020

The effects of
Listeria monocytogenes
hemolysin on lysosomes and phagocytic cells were investigated. Hemolysin caused release of β-glucuronidase and acid phosphatase from suspensions of rabbit and rat lysosomes prepared from liver homogenates. The degree of lysis was proportional to the concentration of hemolysin added. There appeared to be no significant difference between the sensitivities of rat and rabbit lysosomes to disruption. Studies on the effect of
p
H and temperature on lytic activity suggested that hemolysin could function under conditions which might exist within phagocytic cells. Peritoneal exudates from rabbits and mice were exposed to hemolysin and observed by phase microscopy. Hemolysin possessed leucocidal activity and caused degranulation of both rabbit and mouse cells. Optimal activity against lysosomes and peritoneal exudate cells required activation of hemolysin with a reducing agent and could be prevented if hemolysin was previously incubated with cholesterol.
Protective Effect of Vaccines in Experimental
Mycoplasma pneumoniae
Disease
Authors: Fernald Gerald W. , Clyde Wallace A.
Published: January 2020

The mechanisms of immunity to
Mycoplasma pneumoniae
were investigated by evaluating different vaccination procedures in an experimental animal model. Hamsters were immunized by intranasal inoculation of broth cultures or by parenteral injections of saline-suspended organisms. All vaccinees received a standardized intranasal challenge which produced pneumonia in 94% of controls. Intranasal immunization with virulent organisms produced a 71% reduction in pneumonia. Subcutaneous and intraperitoneal inoculation of the same organisms yielded 56 and 61% reductions, respectively. Animals similarly immunized with an attenuated strain developed resistance to pneumonia only after intranasal infection. Serum antibody levels did not correlate with protection. Growth-inhibiting activity was demonstrated in bronchial washings of challenged animals, suggesting the development of local antibody in response to infection with
M. pneumoniae
. Crosschallenge studies were performed in animals vaccinated intranasally with virulent and avirulent variants of the same strain. The avirulent vaccine prevented pneumonia in animals challenged with homologous virulent organisms but not in those receiving an unrelated strain; the virulent vaccine provided protection to both homologous and heterologous challenge. These studies indicate that organism strain variation as well as vaccination technique are important determinants of the immune response to
M. pneumoniae
.
Protective Effect of a Synthetic Polynucleotide Complex (Poly I: C) on Ocular Lesions Produced by Trachoma Agent in Rabbits
Authors: Oh J. O. , Ostler H. B. , Schachter J.
Published: January 2020

Live trachoma agent (TE55) injected into the anterior chamber of the rabbit eye produced the following agent-specific ocular lesions: corneal opacity, corneal neovascularization, and iritis. Three intravenous injections of 1 mg of a potent interferon (IF) inducer, polyriboinosinic acid-polyribocytidylic acid complex (poly I:C), markedly suppressed the ocular lesions produced by the trachoma agent but failed to inhibit the growth of the agent in the ocular tissues. Furthermore, a single intravenous injection of 1 mg of polyriboinosinic acid or of polyribocytidylic acid was also protective, although each failed to induce any detectable circulating IF. These results indicate that a factor or factors other than IF may play a role in the suppression of the ocular lesions produced by trachoma agent in poly I:C-injected rabbits.
Macrophage Migration Inhibition Studies with Cells from Mice Vaccinated with Cell Walls of
Mycobacterium bovis
BCG: Characterization of the Experimental System
Authors: Yamamoto K. , Anacker R. L.
Published: January 2020

The macrophage migration inhibition test was applied to the study of delayed hypersensitivity in mice vaccinated intravenously with oil-treated cell walls of
Mycobacterium bovis
BCG. Migration inhibition of peritoneal exudate cells from sensitized mice was demonstrated directly upon incubation of the cells with purified protein derivative, but indicator cells such as normal peritoneal cells had to be included to demonstrate migration and migration inhibition with sensitized lung cells. Inhibition of migration induced by mouse cells was greatest 3 to 4 weeks after sensitization but was still considerable after 11 weeks. The migration inhibitory factor (MIF) was not detected in cells freshly isolated from sensitized mice but was released into the supernatant fluid when cells were incubated with purified protein derivative for 24 hr at 37 C in a tissue culture system. Production of MIF was inhibited by actinomycin D and puromycin. MIF was nondialyzable, resistant to heating at 56 C for 1 hr, and of a lower molecular weight than mouse gamma globulin. All data indicated that migration inhibition induced by cells from cell wall-vaccinated mice was very similar to that caused by guinea pig lymphocytes.
Reversibility of Heparin Inhibition of the Antibacterial Activity of Polymorphonuclear Leukocyte Lysosomal Proteins
Authors: Clark J. M. , Higginbotham R. D.
Published: January 2020

Inhibition of antibacterial activity of polymorphonuclear leukocytic lysosomal cationic proteins by a polyanion, heparin, can be reversed by addition of the basic nuclear protein, clupeine.
Experimental murine leprosy: growth of Mycobacterium lepraemurium in C3H and C57/BL mice after footpad inoculation
Authors: Closs O
Published: January 2020

Forty-three female C57/BL and C3H mice were inoculated with 2.7 X 10(6) Mycobacterium lepraemurium into each hind footpad. The foot thickness and the number of acid-fast bacilli in the footpad and popliteal and inquinal lymph nodes were recorded. In addition the morphological index and the mean bacillary length were determined in the footpad and in the popliteal lymph node. The bacilli multiplied in both strains during the first 4 weeks after inoculation. After that time no further increase in acid-fast bacilli was observed in the C57/BL strain; the bacilli became elongated and the morphological index decreased. These changes were preceded by a local swelling of the footpad due to the onset of an immune reaction. Thus, under the present conditions, C57/BL mice were able to resist experimental infection with M. lepraemurium by developing an immune response. In C3H mice no indication of an immune reaction was detected, and the bacilli continued to multiply throughout the observation period. The mouse footpad model seems to provide an excellent basis for the use of experimental murine leprosy to study immunity to mycobacterial infections. Certain aspects of the present model are discussed in relation to the mouse footpad model as used in the study of M. leprae infection in mice.
Characterization of a dextranase produced by an oral strain of Actinomyces israelii
Authors: Staat R H , Schachtele C F
Published: January 2020

A dextranase-producing, gram-positive, anaerobic, rod-shaped bacterium isolated from human dental plaque was identified as Actinomyces israeli. Although the extracellular dextranase (EC 3.2.1.11) formed by this microbe appeared to be constitutively produced, the bacterium did not utilize the reaction products as a carbon source during growth. A striking feature of the dextranase was the formation of two distinct groups of oligosaccharide end products. The two groups presumably correspond to the limit dextran and the released reaction product which appeared to be cleaved from the end(s) of larger dextran molecules. Low levels of dextranase activity were measured by [3H]NaBH4 reduction and alcohol fixation of the large, tritiated end products on filter paper disks. Of the carbohydrate substrates tested, only alpha-1,6-linked glucans were cleaved. The enzyme did not exhibit any metal ion requirements, and its pH optimum was 6.3. It is suggested that the A. israelii dextranase may function as a regulatory factor during extracellular in vivo glucan synthesis from sucrose by various plaque microbes.
Neutralizing antibody responses to varicella-zoster virus
Authors: Schmidt N J , Lennette E H
Published: January 2020

Neutralization of varicella-zoster (V-Z) virus by human sera and immune rhesus monkey sera was enhanced by fresh guinea pig complement. There was no marked difference in the degree to which complement enhanced neutralization by sera from current V-Z virus infections and sera from long-past varicella infections. Immunoglobulin G neutralizing antibody in sera from varicella cases was enhanced by complement to a slightly higher degree than was immunoglobulin M (IgM) antibody, and immunoglobulin G neutralizing antibody in immune monkey sera was enhanced to a much greater degree than was IgM antibody. There was a rapid decline in the complement requirement of IgM neutralizing antibodies over the course of immunization of the rhesus monkeys. V-Z neutralizing antibody titers in the presence of complement were higher than complement-fixing titers of the same sera in all groups of individuals studied. IgM neutralizing antibody for V-Z virus was demonstrable in all cases of varicella but in only 1 of 22 zoster cases, and V-Z IgM neutralizing antibody was not detectable in primary herpes simplex virus infections in which heterotypic antibody titer rises occurred to V-Z virus. Complement-fixing antibody for V-Z virus was absent in 19S serum fractions which contained IgM neutralizing antibody for the virus.
Effect of thymectomy and antilymphocyte serum on Mycobacterium leprae infection in mice
Authors: Fieldsteel A H , Gartner S
Published: January 2020

BALB/c mice thymectomized at 3 to 5 days of age were studied to determine if this procedure would result in enhanced susceptibility to infection with Mycobacterium leprae and, if so, whether or not administration of antilymphocyte serum would further increase this susceptibility. The plateau for growth in the footpads of intact mice occurred 4 months after inoculation, whereas in the thymectomized and thymetocomized plus antilymphocyte serum-treated groups the plateau occurred between months 11 and 12 after inoculation. Thymectomy resulted in at least a 10-fold increase in the number of M. leprae found in the footpads. Antilymphocyte serum did not appear to further enhance the M. leprae infection in the thymectomized mice. Although growth of M. leprae in the testes of both intact and thymectomized mice was erratic, the number of organisms reached a higher ceiling in the thymectomized groups. M. leprae harvested from all groups was passaged into intact mice at various intervals after inoculation to test for viability. Viable M. leprae were found at all intervals tested including 22 months after infection in the intact mice, suggesting that a chronic infection occurred that probably lasted during the entire life of the animals.
Characterization of extracellular glucosyltransferase activity of Steptococcus mutans
Authors: Kuramitsu H K
Published: January 2020

The extracellular glycosyltransferase activity of Sterptococcus mutans GS-5 has been resolved into two non-overlapping fractions after gel filtration chromatography on Bio Gel A-15 columns. The activity eluting in the void volume, fraction A, was highly aggregated and synthesized both soluble and insoluble glucans. The activity retarded by the resin, fraction B, synthesized only soluble glucan. Almost all of the extracellular glucosyltransferase activity was eluted in the void volume when the cells were grown in Todd-Hewitt medium. However, most of the activity migrated as the lower-molecular-weight species when cells were grown under conditions which inhibit insoluble glucan formation. The activities in both fractions had identical temperature and pH optima as well as similar Km values for sucrose. Fraction A synthesized both alpha-1,3- and alpha-1,6- linked glucans, whereas fraction B catalyzed alpha-1,6-glucan formation. Fraction B has been purified to near homogeneity and is also aggregated with a subunit molecular weight of 45,000. The properties of the glucosyltransferases in both fractions are discussed in terms of the role of the enzymes in both soluble and insoluble glucan formation.
Cellular location of streptolysin O
Authors: Calandra G B , Theodore T S
Published: January 2020

Streptolysin O was measured in subcellular fractions of group A streptococci obtained after preparation of protoplasts in a hypertonic buffer containing raffinose. Most of the activity was located in the periplasm (the region between cell wall and membrane) and did not differ in several characteristics from that of extracellular streptolysin O. Of the enzymes used as subcellular markers, aldolase and maltase (cytoplasmic) and acid phosphatase (membrane associated) were in the same fractions as found in other bacteria. However, the location of alkaline phosphatase differed from that of other bacteria in the most of the activity was in cytoplasm rather than in the periplasm.
Conditions for production, and some characteristics, of mycobacterial growth inhibitory factor produced by spleen cells from mice immunized with viable cells of the attenuated H37Ra strain of Mycobacterium tuberculosis
Authors: Cahall D L , Youmans G P
Published: January 2020

Mycobacterial growth inhibitory factor (MycoIF), found in supernatant fluids of mouse spleen cell cultures that have been stimulated in vitro with homologous antigen, inhibited the intracellular multiplication of virulent tubercle bacilli within normal mouse peritoneal macrophages in vitro. Antigenically stimulated H37Ra-immunized mouse spleen cells required 72 h of incubation to produce supernatant fluids that would cause intracellular inhibition. Supernatant fluids from 48-h mouse spleen cell cultures were not able to produce intracellular inhibition. Investigation of the culture conditions showed that at lease 1.0% human serum was required in the tissue culture medium for the production of MycoIF by spleen cells from immunized mice. MycoIF activity was noted only in supernatant fluids from spleen cell cultures incubated with antigen for 72 h. MycoIF was nondialyzable and unaffected by freezing, lyophilization, or incubation at 60 C for 30 min. However, MycoIF was inactivated after incubation at 80 C for 30 min. MycoIF was unaffected by low hydrogen ion concentrations (pH 7 to 12), but exposure to higher hydrogen ion concentrations (pH 6, pH 5) significantly decrease MycoIF activity, and exposure to pH 4 to 2 abolished all activity. Supernatant fluids diluted 1:32 were still able to produce significant intracellular inhibition of growth of virulent tubercle bacilli.
Characterization of group A streptococcal R-28 antigen purified by hydroxyapatite column chromatography
Authors: Johnson R H
Published: January 2020

Purified R-28 antigen from an M-protein-poor, R-antigen-rich strain of group A Streptococcus was prepared by sequential treatment of an acid extract of whole cells with ammonium sulfate fractionation and hydroxylapatite (HA) column chromatography. Purified R-28 antigen was eluted only with 0.10 M sodium phosphate, pH 6.7. Findings on quantitative amino acid composition, polyacrylamide gel electrophoresis pattern, and HA column elution pattern were similar but not identical to those previously reported for streptococcal M-proteins. Rabbits immunized with either HA-purified R-28 antigen or heat-killed cells developed two pepsin-sensitive, trypsin-resistant immunodiffusion lines of identity against HA-purified R-28 antigen but failed to form bactericidal antibody. One of these two lines formed a line of identity with R-28 antigen prepared by trypsinization of whole cells. The other line remained undefined, although it appeared not to be either streptococcal group A carbohydrate, M-protein, T-antigen, polyglycerophosphate, E4 antigen, or M-associated protein; by enzymatic criteria it is an R-antigen. Polyacrylamide gel electrophoresis of HA-purified R-28 antigen revealed multiple serologically active charge and size isomers. These findings suggest possible structural similarities between group A streptococcal M-proteins and R-antigens and also indicate that the same purification techniques may be utilized to study these protein antigens if the proper strain of Streptococcus is chosen.
Inhibition of hemolytic activity of the thermostable direct hemolysin of Vibrio parahaemolyticus by ganglioside
Authors: Takeda R , Honda T , Sakural J , Otomo N
Published: January 2020

The hemolytic activity of the thermostable direct hemolysin produced by Vibrio parahaemolyticus was inhibited by a ganglioside mixture. The ganglioside component which inhibited the hemolysin was not FM1 ganglioside.
Production of elevated levels of dextransucrase by a mutant of Streptococcus mutans
Authors: Schachtele C F , Germaine G R , Harlander S K
Published: January 2020

A mutant (S19) of Sreptococcus mutans strain 6715 which produces elevated levels of dextransucrase (EC 2.4.1.5) was isolated. Soluble enzyme in culture supernatant solutions from S19 polymerized the glucosyl moiety of sucrose into alcohol-insoluble and water-insoluble glucans at a rate three to six times greater than that of the parent strain. Washed-cell suspensions of S19 also contained increased amounts of cell-associated enzyme. Adherence of S19 to glass in the presence of sucrose occurred at twice the rate of strain 6715. The Km values for sucrose and primer dextran were similar for the mutant and parent enzymes. Mutant S19 should facilitate studies on the mechanism of adherence of S. Mutans and the control of dextransucrase production by this bacterium.
Dichotomy between macrophage activation and degree of protection against Listeria monocytogenes and Toxoplasma gondii in mice stimulated with Corynebacterium parvum
Authors: Swartzberg J E , Krahenbuhl J L , Remington J S
Published: January 2020

In vivo and in vitro experiments were conducted to determine the effect of Corynebacterium parvum treatment of mice on resistance of Listeria monocytogenes and Toxoplasma gondii. Intravenous immunization with C. parvum conferred transient protection against intravenous challenge with Listeria or an avirulent strain of Toxoplasma but did not protect against a virulent strain of Toxoplasma. Compared with the level of protection conferred by C. parvum, a higher degree of resistance was noted when mice infected with Listeria or Toxoplasma were challenged with the homologous infecting organism. Peritoneal macrophages from mice immunized intravenously with C. parvum were activated to kill Toxoplasma in vitro. Whereas resistance to challenge in vivo was transient, this population of activated macrophages persisted. Peritoneal macrophages from C. parvum mice also markedly inhibited [3H]thymidine uptake by L cells.
Immunologically specific production of interferon in cultures of rabbit blood lymphocytes: association with in vitro tests for cell-mediated immunity
Authors: Bartfeld H , Vilcek J
Published: January 2020

Lymphocytes of animals with delayed hypersensitivity produce mediators of cellular immunity when challenged in vitro with specific antigen. Among these are macrophage migration inhibitory factor (MIF) and interferon (IF). Nonspecific mitogens also induce the production of these lymphokines. In the following study leukocytes and column-purified lymphocytes of the same peripheral blood sample from tuberculin (purified protein derivatives [PPD])-sensitive rabbits were concurrently cultured in medium alone or with PPD. Supernatants of 1- and 4-day lymphocyte cultures were assayed for MIF. Supernatants of 1-, 2- to 4- and 5- to 7-day leukocyte cultures were assayed for IF by inhibition of cytopathic effect of vesicular stomatitis virus on rabbit kidney cultures. In the presence of PPD, normal lymphocytes did not produce MIF, but lymphocytes from sensitized animals did (8/8 animals), after 1 and 4 days of culture. Leukocytes from normal animals produced little or no IF when cultured with or without PPD. Leukocytes from sensitized animals cultured in medium alone produced little IF. However, when cultured with PPD they produced significant amounts of IF on day-1 (6/8 animals) and day-2 to day-4 (4/8) animals. There was no correlation between relative amounts of MIF and IF produced by cultures of respective cells from individual animals. Rabbit IF produced or released in vitro appeared in significant and maximum amounts by 24 h coincident with the time release of significant amounts of another mediator of cellular immunity, MIF.
Defense mechanisms against bovine herpesvirus: relationship of virus-host cell events to susceptibility to antibody-complement cell lysis
Authors: Babiuk L A , Wardley R C , Rouse B T
Published: January 2020

The interaction of infectious bovine rhinotracheitis virus and susceptible host cells was examined to determine whether an infected cell could be destroyed by humoral immune mechanisms before or after the transmission of virus to susceptible adjacent cells. Viral antigens were detectable on cell membranes at 6 h postinfection, but cells were not susceptible to antibody-complement lysis until 10 h postinfection. Intracellular infectious virus was also detectable at 10 h postinfection, and transmission to adjacent cells by the intracellular route began at this time. Extracellular virus was not detectable until 12 to 13 h postinfection. By the continual addition of antibody and complement, virus dissemination could be reduced more than 50-fold. These results support the hypothesis that the humoral immune mechanism may be involved in the recovery from herpesvirus infections.
Endotoxin-binding substances from human leukocytes and platelets
Authors: Springer G F , Adye J C
Published: January 2020

We have found whole human platelets, granulocytes, and mononuclear leukocytes to possess high affinity for the toxic lipopolysaccharide from all gram-negative bacteria tested. We have extracted these cells and platelets with n-butanol-water; all endotoxin-binding activity resided in the organic phase. These endotoxin-binding extracts did not block serologically active groupings on endotoxins or receptors on the erythrocytes. The specificity of these still crude materials was less that that of the highly purified erythrocyte lipopolysaccharide receptor previously described by us, since they bound some bacterial antigens not related to endotoxins. Depending on source, the n-butanol extracts contained 40 to 52% glycerophosphatides (most active), 15 to 22% sphingomyelin, 17% cholesterol, less than 2 to 5% triglycerides, and 7 to 13% inactive peptide. The most active substances in the n-butanol extract were soluble in petroleum ether, whereas the peptide and sphingomyelin were not. Thus, no constituent protein, carbohydrate, or nucleic acid was present in the most highly active material. Polyacrylamide gel electrophoresis of the petroleum ether-soluble material showed for each extract one lipid band only, which was well defined and migrated similarly to phosphatidyllipids. Because of the lipidic nature of the inhibitory substances from leukocytes and platelets we also tested the lipid A component of bacterial endotoxins and some of its derivatives. Lipid A inhibited endotoxin coating of erythrocytes. De-O-acylation of lipid A left amide-linked 3-D-hydroxymyristic acid intact and increased the inhibitory activity of lipid A 20-fold. Complete de-O- and de-N-acylation destroyed its inhibitory effect.
Vi antigen from Salmonella typhosa and immunity against typhoid fever. 11. Safety and antigenicity in humans
Authors: Levin D M , Wong K H , Reynolds H Y , Sutton A , Northrup R S
Published: January 2020

Safety and antigenicity of a purified preparation of Salmonella typhosa Vi antigen was evaluated in human volunteers. Dosages of Vi antigen at 25, 50, and 100 mug were less toxic than U.S. standard typhoid vaccine (lot 6A) containing 5 X 10(8) bacteria per dosage. Vi antigen in comparison with the standard typhoid vaccine induced higher hemagglutinating antibody but lower bactericidal antibody responses.
Antitoxic immunity in experimental cholera: protection, and serum and local antibody responses in rabbits after enteral and parenteral immunization
Authors: Holmgren J , Svennerholm A M , Ouchterlony O , Anderson A , Walletström G , Westerberg-Berndtsson U
Published: January 2020

The protective effect of enternal and parenteral immunization with cholera toxin antigen against experimental cholera in rabbits was studied by using the small-bowel loop technique. Subcutaneous injection of crude toxin as well as purified toxin or toxoids gave rise to significant protection against toxin challenge. The enhanced resistance to toxin was found to correspond to a many-fold higher magnitude of protection against challenge with live vibrios. In the primary response the protection increased during the first month. Booster immunization gave rise to a further increased immunity which, however, declined rapidly. Multiple oral or repeated intraintestinal antigen administrations also induced protective antitoxic immunity although of less magnitude than that obtained by parenteral immunization. Enteral and, to a lesser extent, parenteral immunization gave rise to increased antitoxic antibody titers and immunoglobulin levels in intestinal washings and mucosa scraping. Immunoglobulin G (IgG) and IgG antitoxins predominated, but after enteral immunization total IgA and specific IgA antibodies occasionally reached levels similar to those for IgG. In serum, significantly increased antibody levels (IgG) were only recorded after parenteral immunization. Both the primary binding and the neutralizing antitoxin titers showed a stayistically significant correlation with the degree of protection against toxin challenge; however, for the neutralizing antibodies this correlation was not without exceptions. No relation to protection was found for intestinal antibodies. The results of the present study indicate that enternal as well as parenteral immunization with toxin antigen can give rise to effective cholera immunity. After enternal immunization, the protection appears to be medicated by locally synthesized antibodies. After parenteral vaccination both serum-derived and locally produced antibodies seem to be effective.
Antigens of Streptococcus mutans: characterization of a polysaccharide antigen from walls of strain GS-5
Authors: Wetherell J R , Bleiweis A S
Published: January 2020

A cell wall-associated polysaccharide antigen was isolated from Streptococcus mutans GS-5 and appeared to determine serotype c specificity. Ouchterlony double-diffusion analysis of crude formamide extracts derived from purified cell walls of two serotype c strains (GS-5 and JC-2) showed complete identify when reacted with anti-GS-5 sera. Immunoelectrophoresis of this extract demonstrated the typical mobility for this serotype as described by others. Column chromatography on BioGel P-100 of the crude formamide extracts derived from GS-5 walls resulted in a single antigenic peak being resolved. This material, when loaded onto a diethylaminoethylcellulose column and eluted with a linear gradient of ammonium carbonate (0.0 to 0.2 M), was resolved further into two serologically reactive peaks (I and II). Only two consituents, rhamnose and glucose, were detected in the purified column fractions. Peak 1 had a rhamnoseto-glucose molar ratio of 0.9:1.0, and peak II, the major resolvable fraction, had a molar ratio of 1.7:1.0, The peak II ratio was very similar to that found in the formamide extract residue pellet (1.6:1.0)9 Ouchterlony analysis of the crude formamide extract and the purified fractions revealed only partial identify between peaks I and II but complete identify between peak II and the crude extract. Likewise, immunoelectrophoresis showed no differences in mobility of peak II and the crude extract, whereas peak I moved towards the cathode. Possible structural relationships between the two antigenic fractions are discussed below. Hapten inhibition studies suggested that an alpha-glucosyl group is at the immunodeterminant site of the antigen.
Multiple sclerosis-associated agent: transmission to animals and some properties of the agent
Authors: Koldovsky U , Koldovsky P , Henle G , Henle W , Ackermann R , Haase G
Published: January 2020

In confirmation and extension of observations by Carp and his associates, brain tissue and sera from patients with multiple sclerosis (MS) were found to harbor an agent which induces a transitory depression in polymorphonuclear leukocytes (PMN) in mice as well as in rats, hamsters, and guinea pigs. All of eight MD brains contained this agent at titers as high as 10(-9)/g of brain tissue. The agent was found in MS sera at titers up to 10(-3)/ml of serum, but its presence depended to some extent on the clinical status of the patients; it was observed more frequently in sera of patients with active disease (73%) thatn in sera of patients with quiescent disease (31%). Control brain tissues or sera failed to induce PMN depression. The apparently MS-associated agent (MSAA) passed through 50-nm but not 25-nm membrane filters (Millipore Corp.) and was largely sedimented at 105,000 X g but not at 50,000 X g for 1 h. It multiplied to high titers in the central nervous tissue of the inoculated animals and could be serially transmitted from animal to animal by passage of brain homeganates. Various observations and considerations appear to preclude that MS-associated agent represents an indigenous animal virus. Although its role in MS remains to be determined, it should be considered a candidate for the etiology of this disease.
Insect immunity. 11. Simultaneous induction of antibacterial activity and selection synthesis of some hemolymph proteins in diapausing pupae of Hyalophora cecropia and Samia cynthia
Authors: Faye I , Pye A , Rasmuson T , Boman H G , Boman I A
Published: January 2020

We have previously shown that pupae of the giant silkmoth Samia cynthia have a humoral antibacterial activity, which was induced by viable, nonpathogenic gram-negative bacteria (H.G. Boman et al., 1974). We show here that this activity was formed simultaneously with a selective incorporation of amino acids into eight polypeptide chains characterized by their electrophoretic behavior. If actinomycin D or cycloheximide were given at an early time, no antibacterial activity was found. If the inhibitors were given at the time of maximum activity, there was no effect with actinomycin D but a rapid decrease of the activity in the case of cycloheximide. The results imply that the messenger ribonucleic acid was stable, but that at least one protein component was turning over. Hemolymph from immunized pupae of another giant silkmoth, Hyalophora cecropia, was fractionated by ammonium sulfate precipitation. This procedure, together with the isotope distribution after co-electrophoresis in polyarylamide gels, was used for comparing the response to injury and to different infections. Almost identical polypeptide patterns were obtained as a response to an infection with either viable Enterobacter cloacae or Bacillus subtilis. These patterns differed both qualitatively and quantitatively from the injury effect created by an injection as such. There was only a low antibacterial activity in each of the four fractions obtained by ammonium sulfate precipitation. However, a combination of three fractions restored a high killing activity. Fractionation of hemolymph from untreated pupae provided evidence for at least one preexisting factor which stimulated the killing of Escherichia coli. The osmotic pressure of the bacteria contributed to the antibacterial activity towards E. coli, but not towards B. subtitlis. The killing of E. coli was inhibited by liped A and, to a lesser extent, by an inhibitor of proteolytic enzymes. The similarities and differences with the mammalian complement system are discussed.
Role of Ca2+ and Mg2+ in some human neutrophil functions as indicated by ionophore A23187
Authors: Estensen R D , Reusch M E , Epstein M L , Hill H R
Published: January 2020

Studies with the divalent cation ionophore A23187 suggest that both Ca2+ and Mg2+ ion influx play a role in human peripheral blood neutrophil function. Degranulation of neutrophils occurred at ionophore concentrations of 10(-5) M and was Ca2+ but not Mg2+ dependent. Modulation of neutrophil chemotaxis was enhanced optimally by 10(-7) M ionophore and was both Ca2+ and Mg2+ dependent. Concentrations of ionophore as low as 10(-12) M seemed to sensitize the cells to a concentration of phorbol myristate acetate which by itself was not chemotactic. These findings also indicate that factors other than Ca2+ or increases in cyclic nucleotides are important to initiation and modulation of neutrophil function.
Demonstration of the cardiotoxicity of the thermostable direct hemolysin (lethal toxin) produced by Vibrio parahaemolyticus
Authors: Honda T , Goshima K , Takeda Y , Sugino Y , Miwatani T
Published: January 2020

Intravenous injection of the thermostable direct hemolysin (lethal toxin) produced by Vibrio parahaemolyticus caused rapid death of rats. Studies by electroencephalography and electrocardiography showed that after intravenous injection of the toxin the electroencephalogram remained normal for quite a long time after the heart of the animals had stopped beating. Depression of intraatrial and intraventricular conduction of electrical activation, including atrioventricular block, was observed in electrocardiograms of animals injected with the toxin. The toxin was also found to be toxic to cultured mouse heart cells. When it was added to the medium, the beating rhythm of the cultured heart cells increased temporarily and then soon stopped abruptly. The effect of the toxin on cultured mouse heart cells was blocked by preincubation of the toxin with a ganglioside mixture. From these results it is concluded that the thermostable direct hemolysin (lethal toxin) had cardiotoxic activity, and thus administration of the toxin causes rapid death of animals.
Microcapsule of type III strains of group B Streptococcus: production and morphology
Authors: Baker C J , Kasper D L
Published: January 2020

The yield of purified type III polysaccharide of group B Streptococcus was significantly improved by modification of the growth medium. Culture of organisms in standard Todd-Hewitt broth resulted in acid accumulation during the exponential phase of growth and poor yield of type III polysaccharide when extracted from cells by washing with neutral buffer solution. By increasing the buffering capacity of the broth medium, acid accumulation was prevented, and the number of viable cells was increased at the stationary phase of growth. Further, by increasing the concentration of glucose in the buffered medium, the yield of type III polysaccharide was increased two to three times. Electron microscopic investigations of cells grown in the modified broth medium demonstrated a thicker microcapsule than was found in organisms grown in standard broth.
Variability in the structural polypeptides of herpes simplex virus 1 strains: potential application in molecular epidemiology
Authors: Pereira L , Cassai E , Honess R W , Roizman B , Terni M , Nahmias A
Published: January 2020

This paper reports on the variability of structural polypeptides of 53 strains of herpes simplex virus 1 isolated from Italy, Uganda, South Africa, and various locations in the United States. Most strains were passaged a limited number of times at low multiplicity outside the human host; a few strains were characterized by numberous passages at variable multiplicities in cell culture and experimental animals. The acrylamide gel electrophoresis of polypeptides from purified virions revealed seven variable polypeptides. Virion polypeptides (VP) 7, 11, 13, 14, 15.2 and 23 were present in at least two isotypic forms characterized by fast and slow electrophoretic mobilities. VP8 could not be detected in three strains. In addition, VP13, 15.2, and 23 in some strains were either absent or comigrated with other polypeptides. A variety of tests showed that the variability in electrophoretic mobility of polypeptides was reproducible and could not be attributed to artifacts of purification, solubilization, or electrophoresis. Attempts to classify the strains on the basis of electrophoretic mobility of five or all seven variable polypeptides yielded 14 and 19 groups, respectively. The bulk of the strains (41 to 53) fell into six groups. Not all possible permutations of variable polypeptides were observed. Comparison of early and late passages of laboratory strains showed that in the few instances tested the variability could not be attributed to the propagation of the virus outside the human host. Clustering of strains on the basis of country of origin was not observed. Some clustering of isolates on the basis of site of isolation was observed, and the data do suggest that further analyses of isolates for evidence of a correlation between the site of localization on the human body and the structural polypeptides might be useful. Electrophoretic characterization of structural polypeptides has the potential of becoming a powerful tool for epidemiological studies of herpes simplex virus infections.
Mycoplasma pneumoniae in hamster tracheal organ culture studied by scanning electron microscopy
Authors: Muse K E , Powell D A , Collier A M
Published: January 2020

Hamster tracheal rings in organ culture were inoculated with a virulent strain of Mycoplasma pneumoniae and examined by scanning electron microscopy. A progressive increase in epithelial cell injury was detected from 48 to 96 h post-inoculation and was characterized by apparent loss of the apical portion of ciliated cells. M. pneumoniae attaching to the epithelial cell surfaces could be identified by comparison with the surface morphology of mycoplasmas grown on glass cover slips.
Characteristics of cells present in peritoneal fluids of mice injected intraperitoneally with Bordetella pertussis
Authors: Fishel C W , Halkias D G , Klein T W , Szentivanyi A
Published: January 2020

Peritoneal fluids obtained from mice after the intraperitoneal administration of Bordetella pertussis vaccine, heated vaccine, an extract of the organisms, killed Escherichia coli, or thioglycolate medium were examined in terms of total cells and percentage that adhered to glass cover slips during 2-h incubation period. All these substances were found to increase the number of leukocytes in peritoneal fluid within 1 to 2 days after the injection. This increase appeared to be due to an influx of macrophages and polymorphonuclear leukocytes with relative proportions at a given time dependent upon the material involved in the induction of the response. The initial increases after pertussis vaccine seemed to be due mainly to an influx of monomuclear cells, whereas with E. coli neutrophils constituted the major portion of the cell population. The percentage of peritoneal cells that attached to glass was also found to be markedly reduced in preparations obtained from mice after the injection of B. pertussis or E. coli. There appeared to be differences in persistence of this phenomenon, with preparations containing the histamine-sensitizing factor being the most active in affecting adherence properties. Thus these data would suggest that the action of B. pertussis on macrophages (or precursors) and neutrophils is not expressed in terms of suppression of emigration properties, as has been reported by others for lymphocytes, but is manifested in the alteration of glass-adherence characteristics. Within experimental limitations, it is believed that macrophages are possibly more involved in terms of altered function than are the polymorphonuclear cells.
Identification of sialic acid in polysaccharide antigens in group B Streptococcus
Authors: Baker C J , Kasper D L
Published: January 2020

By means of paper chromatographic techniques with purified, sialic acid-containing, bacterial antigen standards, sialic acid, as well as galactose and glucosamine, have been identified as components of each type-specific antigen of group B Streptococcus. Rhamnose was not detected in the group B antigen isolated by the classical HCl and heat extraction method.