bluuebunny/crossref_metadata_2025 huggingface dataset:
Side effects of immunization with liver attenuated Trypanosoma cruzi in mice and rabbits
Authors: Basombrío M A , Besuschio S , Cossio P M
Published: January 2020

Immunity against lethal, bloodstream forms of Trypanosoma cruzi was achieved in mice by preinoculation of approximately equal to 10(5) culture epimastigotes of an attenuated T. cruzi strain (TCC). The risks of TCC inoculation in terms of pathogenicity or eventual increase in virulence of TCC progeny were evaluated. No pathogenic parasites could be selected from TCC progeny by either mouse, triatome, or culture passages. Immunizing doses of live TCC did not induce in adult mice alterations resembling chronic Chagas' disease, as judged by patterns of mortality, tissue damage, autoantibodies, or parasite recovery. On the basis of the same criteria, However, a remarkable similarity could be established between the disease caused in mice by inoculation of low numbers (10(2)) of pathogenic trypomastigotes and human chronic Chagas' disease. Although patent parasitemias were never revealed in fresh blood mounts obtained from TCC-inoculated mice, a few hemocultures and xenodiagnoses gave positive results, particularly soon after inoculations at birth. The parasites recovered by either method remained in the attenuated, epimastigote stage. In rabbits, no local lesions, fever, weight loss, or histopathological alterations were detected after subcutaneous inoculation of 10(7) TCC organisms, although one fifth of the animals yielded positive hemocultures of epimastigotes. The contrasting host response to cultured epimastigotes as compared with blood trypomastigotes indicates that, in experimental Chagas' disease, immunoprotection is not necessarily associated with immunopathology.
Inhibitors of coaggregation between Actinomyces viscosus T14V and Streptococcus sanguis 34: beta-galactosides, related sugars, and anionic amphipathic compounds
Authors: McIntire F C , Crosby L K , Vatter A E
Published: January 2020

Coaggregation between Actinomyces viscosus T14V (T14V) and Streptococcus sanguis 34 (Ss34) depends upon specific reaction between lectin on T14V and carbohydrate on Ss34. Studies on coaggregation inhibition by sugars related to D-galactose, beta-galactosides, and amphipathic molecules revealed: (i) D-fucose, D-talose approximately equal to D-galactose, which was 0.2 potency of lactose. No other hexoses or pentoses inhibited at 0.1 M. (ii) Gal beta (1 leads to 3)GalNAc alpha OCH2C6H5 was the most potent beta-galactoside inhibitor; it had 20 times the potency of lactose. (iii) Anionic nonaromatic amphipathic compounds were good inhibitors; sodium deoxycholate (I) was equal to lactose; sodium dodecyl sulfate (II) had 15 times the potency of lactose; there was 90 to 100% irreversible inhibition when T14V was treated with 0.005 M (II). Treatment of Ss34 with II had no effect. (iv) Synergism of inhibition was observed between lactose and I or lactose and II, e.g., inhibition by 0.01 M lactose = 5%; inhibition by 0.01 M I = 9%; inhibition by 0.01 M lactose + 0.01 M I = 87%. (v) The irreversible inhibition by II was prevented when 0.25 M lactose or 0.25 M I was present during treatment of T14V with 0.005 M II. (vi) Synergism and prevention by lactose or by I of irreversible inhibition by II suggest that all three react at the same site on T14V lectin. We hypothesize that the T14V lectin combining site for Ss34 carbohydrate has specific affinity for beta-galactosides and for anionic nonaromatic amphipathic molecules. This site can be saturated by either kind of reagent to exclude the other reagent or to inhibit coaggregation.
Antigenic stimulation of T lymphocytes in chronic nononcogenic retrovirus infection: equine infectious anemia
Authors: Shively M A , Banks K L , Greenlee A , Klevjer-Anderson P
Published: January 2020

Equine infectious anemia is a chronic disease of horses caused by a nononcogenic retrovirus. Studies were undertaken to determine the types of cells involved in the in vitro lymphoproliferative response to viral antigens and the dynamics of this reaction. It was observed that reactive lymphocytes were present at unpredictable times in the peripheral blood of infected horses. This reaction was shown to be specific for the interaction of equine infectious anemia virus and T lymphocytes. Enriched B-lymphocyte populations did not divide when exposed to equine infectious anemia virus. Macrophages were depleted from the reaction by two methods: adherence to Sephadex and a combination of binding to Sephadex and adherence to complement-coated erythrocytes. Both methods reduced the number of monocytes, but only the combination of Sephadex and complement-coated cells removed the accessory cells needed for lymphocyte proliferation. We conclude that during the chronic stages of equine infectious anemia the number of antigen-reactive T lymphocytes fluctuates within the peripheral blood and that these cells require a complement-binding cell for reaction. The relationship of these cells to the lymphoproliferative stages of this disease is discussed.
Specificity of a mycoplasma mitogen for lymphocytes from human and various animal hosts
Authors: Cole B C , Washburn L R , Sullivan G J , Ward J R
Published: January 2020

Spleen lymphocytes from Lewis and Buffalo rats and peripheral blood lymphocytes from 10 human donors exhibited high levels of transformation when exposed to Mycoplasma arthritidis supernatants. In contrast, spleen lymphocytes from rabbits and guinea pigs and peripheral blood lymphocytes from sheep and calves failed to transform when exposed to M. arthritidis supernatants. The lymphocytes from all hosts were transformed in the presence of phytohemagglutinin or concanavalin A or both Serological studies failed to provide evidence that the responding hosts were presensitized against M. arthritidis antigens.
Cross-reactive, cell-associated antigen on L929 cells infected with temperature-sensitive mutants of sindbis virus
Authors: Wolcott J A , Gates D W , Wust C J , Brown A
Published: January 2020

Temperature-sensitive (ts) mutants of Sindbis virus (SIN) were used to aid in the identification of alphavirus cross-reactive proteins on the surface of infected cells by antibody-dependent, complement-mediated cytolysis. Antisera prepared in rabbits against purified SIN or Semliki Forest viruses were highly cytotoxic for cells infected with wild-type SIN and for cells infected at the permissive temperature with maturation-defective, ts mutants of SIN belonging to several distinct complementation groups. When these SIN mutants were analyzed by antibody-dependent, complement-mediated cytolysis at the restrictive temperature only cells infected with the SIN mutant of complementation group E, ts20, participated in both homologous (with anti-SIN serum) and heterologous (with anti-Semliki Forest virus serum) antibody-dependent, complement-mediated cytolysis reactions. These data and the known defect of ts20 suggested that the cell-associated viral E1 glycoprotein was a functional target antigen for homologous and cross-immunoreactivity in alphavirus-infected cells. At the restrictive temperature there were quantitative differences in antibody-dependent, complement-mediated cytolysis reactivity of ts20- versus wild type-infected cells consistent with the suggestion that ts20-infected cells do not fully express all of the homologous or the cross-reactive antigenic determinants found in wild-type infection. Additional potential sites for antigenic determinants involved in alphavirus-immune cross-reactivity are discussed in relation to events in virus maturation.
Ocular Albumin Fluorophotometric Quantitation of Endotoxin-Induced Vascular Permeability
Authors: Cousins Scott W. , Rosenbaum James T. , Guss Robert B. , Egbert Peter R.
Published: January 2020

Bacterial endotoxin (lipopolysaccharide; LPS) is known to alter systemic vascular permeability, but this effect is difficult to monitor and quantitate in vivo. The ocular vessels of the rabbit are particularly sensitive to LPS. Using a slit lamp equipped with a fluorophotometer, we have adapted a method to quantitate endotoxin-induced ocular vascular permeability by measuring the accumulation of fluorescein isothiocyanate-conjugated albumin into the anterior chamber of the eye. After intravenous administration of
Salmonella typhimurim
LPS, the anterior chamber fluorescence and blood fluorescence were measured at intervals of 15 min and 1 h, respectively, over 4 h. In controls, maximal fluorescence in the anterior chamber was 3.1 ± 0.8% of blood fluorescence. Doses of LPS as low as 0.25 μg/kg produced an ocular/serum fluorescence ratio of 17.6 ± 4.9. A dose of 2.5 μg of LPS per kg tended to produce a higher ratio (68.0 ± 7.1) than a larger dose of 50 μg/kg (30.5 ± 16.6). Permeability changes began within 30 min after LPS, and the rate of dye accumulation varied over time, with maximal leakage usually occurring 90 min after LPS, but occasionally occurring much later. Repeated doses produced tolerance. By conjugating albumin to rhodamine and utilizing a second filter with the slit lamp to measure accumulation of this dye, we demonstrated the persistence of marked permeability during a period when intraocular fluorescein isothiocyanate and albumin levels were relatively constant. This methodology indicates that extremely low doses of LPS induce ocular permeability changes and that neither the time course nor the dose response of this effect is linear. Ocular fluorophotometry is a sensitive, noninvasive technique to study the dynamics and pharmacology of LPS-induced permeability changes.
Phage influence on the synthesis of extracellular toxins in group A streptococci
Authors: Nida S K , Ferretti J J
Published: January 2020

Phage conversion of group A streptococci to produce streptococcal exotoxins was shown to occur more widely than has been previously reported. Toxigenic conversion was found in 19 newly constructed lysogenic and pseudolysogenic strains resulting in synthesis of exotoxin types A and B. Conversion was accomplished by a positive conversion effector, which was a phage characteristic expressed by the prophage and vegetatively reproducing phage. Exotoxin production was determined by the rabbit skin test and by countercurrent immunoelectrophoresis with type-specific antisera. New lysogens and pseudolysogens were constructed with strains which failed to produce at least one exotoxin type. Phages were obtained from toxigenic strains isolated from cases of scarlet fever. Conversions were consistent and repeatable; loss of the recently introduced phage was accompanied by loss of the newly acquired toxin productivity. Conversion resulted in production of additional exotoxin type or types and never affected existing toxin synthesis. Converting phages were characterized by electron microscopy and negatively stained preparations and were all found to be of morphological class B1. All phage nucleic acid was double-stranded DNA. Though similar in structure, each converting phage had a different host range, and the nine new converting phages identified here did not react with antiserum prepared against the originally reported converting phage.
Monoclonal antibodies of four different specificities for neutralization of type 1 polioviruses
Authors: Humphrey D D , Kew O M , Feorino P M
Published: January 2020

Four independent hybridoma clones have been established that produce neutralizing antibodies specific to type 1 poliovirus. Each clone produced antibody which neutralized a distinct set of type 1 test strains: (i) all 15 strains tested; (ii) the inducer strain only; (iii) predominantly wild strains; or (iv) all vaccine-related and some wild strains.
Antiviral effects of interferon on a somatic cell hybrid between two Burkitt's lymphoma cell lines of different interferon sensitivities
Authors: Lidin B , Lamon E W
Published: January 2020

A somatic cell hybrid between two human Burkitt's lymphoma cell lines, Raji and Daudi, was infected with either Epstein-Barr virus or vesicular stomatitis virus after interferon treatment. Raji cells are resistant to the antiviral effects of exogenously added interferon, whereas Daudi cells are interferon sensitive. The Raji-Daudi hybrid showed an interferon sensitivity that was intermediary to that of the parental cells against both viruses.
Mannose-inhibitable adhesins and T3-T7 receptors of Klebsiella pneumoniae inhibit phagocytosis and intracellular killing by human polymorphonuclear leukocytes
Authors: Pruzzo C , Debbia E , Satta G
Published: January 2020

It has recently been shown that Klebsiella pneumoniae strains adhere to human epithelial cells and that adherence is mediated by mannose-inhibitable adhesins which are also receptors for coliphages T3 and T7. We have now found that Klebsiella strain K59, which adheres to human epithelial cells and carries the receptors for coliphages T3 and T7, adheres to human polymorphonuclear leukocytes (PMN) at 4 degrees C. Strains KRTT1 and KRTT2, which are spontaneous mutants unable to adsorb coliphages T3 and T7 and adhere to human epithelial cells, at this temperature did not adhere to PMN. Adherence of K59 cells to PMN at 4 degrees C was inhibited by D-mannose, by UV-inactivated T7 phages, and by pepsin-digested anti-K59 antibodies absorbed with KRTT1 cells. At 37 degrees C the number of PMN with KRTT bacteria associated was fourfold higher than at 4 degrees C. On the contrary, the number of PMN with K59 bacteria associated at this temperature was fourfold lower than at 4 degrees C. Phagocytosis and intracellular killing experiments performed at 37 degrees C showed that KRTT1 and KRTT2 were phagocytized and killed at a higher rate than K59. After blocking of the mannose-inhibitable adhesins and T3-T7 receptors (MIAT) by D-mannose, UV-inactivated bacteriophage T7, or specific antibodies, K59 cells became more sensitive to phagocytosis and intracellular killing at 37 degrees C. K59 cells lysogenic for prophage AP3 were approximately as sensitive to phagocytosis and intracellular killing by human PMN as strains KRTT1 and KRTT2. Unencapsulated Klebsiella strains isolated from clinical specimens were found to carry MIAT most often. Four such strains were found much more resistant to phagocytosis and intracellular killing than their spontaneous mutants resistant to bacteriophages T3 and T7.
Predominant cultivable microflora of human dental fissure plaque
Authors: Theilade E , Fejerskov O , Karring T , Theilade J
Published: January 2020

Plaque developed in 10 occlusal fissures from unerupted third molars during implantation for 200 to 270 days in lower molars of dental students was studied. To characterize the predominant cultivable flora, 592 isolates (51 to 67 from each fissure) were subcultured from anaerobic roll tubes. Twenty-eight of the isolates were lost. Streptococci constituted 8 to 86% (median, 45%) of the isolates, Streptococcus mutans constituted 0 to 86% (median, 25%) and S. sanguis constituted 0 to 15% (median, 1%). A few isolates of "S. mitior" and "S. milleri" were found, but no S. salivarius. Staphylococci made up 0 to 23% (median, 9%). Gram-positive rods constituted 6 to 59% (median, 35%). Of these, 0 to 46% (median, 18%) were Actinomyces naeslundii and A. viscosus, but no anaerobic actinomyces were isolated. Arachnia and propionibacteria made up small proportions, lactobacilli were isolated from two fissures, constituting 10 and 29%, and eubacteria were isolated from one fissure (27%). Gram-negative cocci made up 0 to 46% (media, 4%). Only two isolates of gram-negative rods were found, both facultative anaerobes. Although 8 of the 10 fissures had large proportions of S. mutans, lactobacilli, or both, no caries was found even with microradiography. The large individual variation probably reflects differences in initial colonization from saliva and in growth conditions in each fissure.
Cell-mediated and humoral immunity induced by a live Francisella tularensis vaccine
Authors: Koskela P , Herva E
Published: January 2020

Live attenuated Francisella tularensis vaccine induced long-lasting humoral and cell-mediated immune responses in all 13 subjects studied. Lymphocyte blast transformation reactivity to F. tularensis appeared 2 weeks after vaccination in most subjects and remained unchanged for up to 1.5 years. Similarly, in most recipients, antibodies against F. tularensis were detectable by both the enzyme-linked immunosorbent assay (ELISA) and the agglutination method from 2 weeks after vaccination, although diagnostically significant agglutination titers (greater than or equal to 80) were not detectable until 4 weeks after vaccination. Maximal agglutination titers of 80 to 2,560 appeared at 4 to 8 weeks, and in spite of decreasing tendency, titers as high as 320 were still present 1.5 years after vaccination. ELISA showed the simultaneous, but not parallel, appearance of different immunoglobulin classes, immunoglobulin M (IgM) reaching individual maximal values 1.8 months after vaccination on average, at the same time as agglutinating antibodies, 1 week earlier than IgA, and about 1 month earlier than IgG. All of these immunoglobulin classes persisted in significant amounts up to 1.5 years, with IgG generally dominant. Long-lasting IgA and IgM responses after vaccination, as also after infection, suggested that the serodiagnosis of tularemia generally requires two consecutive serum samples with a significant increase in the titer.
Neutralizing antibody response of rabbits and goats to caprine arthritis-encephalitis virus
Authors: Klevjer-Anderson P , McGuire T C
Published: January 2020

Rabbits were immunized with purified caprine arthritis-encephalitis virus and examined for neutralizing activity. Analysis of virus-antiserum interaction at 37 degrees C demonstrated little loss of viral infectivity after incubation with heat-inactivated rabbit antiserum for 60 min. However, sensitization of virus (as assessed by the addition of complement) occurred almost immediately and was 95% complete after 10 min. The complement-dependent neutralizing activity was associated with the immunoglobulin G fraction of rabbit antiserum. Addition of goat anti-rabbit immunoglobulin G to the immune rabbit serum-caprine arthritis-encephalitis virus mixture also resulted in neutralization of infectivity when unbound antibody was removed before addition of the anti-immunoglobulin. Serum from most caprine arthritis-encephalitis virus-infected goats contains antibody activity to the core protein p28, as demonstrated by immunodiffusion and enzyme-linked immunosorbent assay. However, attempts to demonstrate neutralizing activity in the serum of goats up to 1.5 years post-inoculation or in serum of hyperimmunized goats were unsuccessful when the sera were examined alone or in combination with complement or rabbit anti-goat immunoglobulin or both.
Recovery from T cell depletion during murine listeriosis and effect on a T-dependent antibody response
Authors: Chan Y Y , Cheers C
Published: January 2020

During the infection of mice with Listeria monocytogenes, there is a profound depletion of T (Thy-1+ Ig-) lymphocytes between days 1 and 4, followed by an increase in T cells to three times normal levels by day 9. The recovery of T cell numbers required cell proliferation, being sensitive to vinblastin and cyclophosphamide. Adult thymectomy 6 months before infection had no effect on recovery. The repopulating cells were no more sensitive than normal T cells to hydrocortisone. B lymphocytes (Ig+ cells) and null (Thy-1-Ig-) cells increased from day 1 after the injection of either live or (in contrast to T cells) killed Listeria organisms. Their increase was inhibited by vinblastin and cyclophosphamide. Despite T cell depletion, no depression of the antibody response to the T-dependent antigen, sheep erythrocytes, occurred during infection or when spleen cells were adoptively transferred from infected mice to irradiated recipients.
Innate resistance of mice to Salmonella typhi infection
Authors: O'Brien A D
Published: January 2020

The basis for the natural resistance of mice to Salmonella typhi was examined. In contrast to Salmonella typhimurium, the virulence of S. typhi for mice was independent of the mouse strain and was not affected by inactivation of murine macrophages with silica. However, mice were more susceptible to S. typhi when given iron alone or iron and an iron chelator. The results suggest that the failure of S. typhi to undergo net growth in murine tissues reflects an inability of the bacterium to multiply rather than rapid killing by resident macrophages.
Characterization of a Galactose-Specific Lectin from
Actinomyces viscosus
by a Model Aggregation System
Authors: Heeb Mary J. , Costello Ann H. , Gabriel Othmar
Published: January 2020

A simple model system has been developed in which lectin-mediated aggregation of glycoprotein-coated beads can be monitored by following the decrease in light scattering at 650 nm. Aggregation has been characterized with the lectin of
Actinomyces viscosus
T14V. Its dependence on pH, temperature, and stirring rate was examined, and the number of bacterial cells in relation to the number of latex beads resulting in optimal aggregation was established. This system has the advantage of permitting the study of a single ligand of defined structure. The ligand density was determined with radiolabeled glycoproteins. Under the conditions of the assay, ligand leakage was less than 3%, and ligands were not displaced from the beads by various proteins, glycoproteins, or by other components present in the assay mixture. Latex beads coated with asialofetuin aggregate upon the addition of
A. viscosus
T14V cells. By contrast, when asialofetuin was first extensively treated with purified galactose oxidase, no aggregation occurred. Only after reduction with NaBH
4
was aggregation restored, demonstrating that galactose termini of asialofetuin are essential for the binding of
A. viscosus
lectin. An absolute requirement for calcium was also demonstrated. Various sugars inhibited aggregation in the following order, starting with the most effective: lactose, methyl-β-D-galactopyranoside, galactose,
N
-acetylgalactosamine, methyl-α-D-galactopyranoside. Beads coated with fimbriae from
A. viscosus
coaggregated with neuraminidase-treated human erythrocytes and with
Streptococcus sanguis
cells. In each instance the aggregation was inhibited by lactose, indicating that the
A. viscosus
lectin is located in the fimbriae. Cells grown under different conditions differed in their effectiveness in aggregating glycoprotein-coated beads, suggesting differences in lectin density or accessibility. Two different experimental designs were used to establish the minimum ligand density for aggregation to occur. In one type of experiment, a threshold concentration was found for asialo α
1
-acid glycoprotein, but not for asialofetuin. With an alternate approach in which a different population of galactose residues was exposed, a threshold phenomenon was also demonstrated for asialofetuin. The importance of structural ligand features in the aggregation assay is discussed in view of these findings.
Purification of an outer capsid glycoprotein of neonatal calf diarrhea virus and preparation of its antisera
Authors: Matsuno S , Inouye S
Published: January 2020

An outer capsid glycoprotein, VP 7, was purified from a bovine rotavirus, neonatal calf diarrhea virus, by isoelectric focusing in glycerol gradients after disruption of the outer capsid. Its isoelectric point was found to be about 4.5. Guinea pigs were immunized with this VP 7 preparation. The antisera possessed both neutralizing and hemagglutination-inhibiting activities as well as complement-fixing activity, suggesting that VP 7 is a protein involved in hemagglutination and initiation of infection. When these antisera were reacted with a simian rotavirus, their antibody titers were low by hemagglutination-inhibiting and complement-fixing assays, but one serum neutralized the simian rotavirus as efficiently as it did homologous neonatal calf diarrhea virus.
Safety and immunogenicity of a group 29E meningococcal capsular polysaccharide vaccine in adults
Authors: Griffiss J M , Brandt B L , Altieri P L , Pier G B , Berman S L
Published: January 2020

A serogroup 29E Neisseria meningitidis capsular polysaccharide vaccine at a dose of 50 micrograms was injected subcutaneously into 10 adult human volunteers. One vaccinate experienced a mild systemic reaction; one complained of moderate to severe local pain and tenderness. The vaccine induced significant homologous binding and bactericidal antibody by 2 weeks and significant binding antibody against the heterologous serogroup Z capsular polysaccharide by 4 weeks. Although binding antibody rose during the first 4 weeks and then declined slowly over the subsequent 4 months, bactericidal antibody response declined substantially by 4 and 8 weeks for both polysaccharides. The increase in group 29E bactericidal activity was no longer significant at 4 and 8 weeks; loss of bactericidal activity against group Z was significant by 8 weeks. Bactericidal activity again rose between 8 and 26 weeks, becoming significantly increased over prevaccination levels for group 29E and increased, though not significantly (P = 0.085), over prevaccination levels for group Z. As a result of the failure of induced antibody to increase bactericidal activity, only 40% of vaccinates achieved a greater than 2 log2 increase in lytic activity against group 29E, and none achieved this large an increase in lytic activity against group Z.
Effects of carrier ampholyte contamination on the biological and biochemical properties of streptococcal pyrogenic exotoxin type C
Authors: Bloomster T G , Watson D W
Published: January 2020

Three streptococcal pyrogenic exotoxins (SPEs), designated as SPE A, B, and C, have been purified and characterized. Routine purification of the SPEs includes the technique of isoelectric focusing. An earlier study showed that the removal of commercial carrier ampholytes (Ampholines) from SPE was difficult. The physiochemical properties of SPE C were previously reported; however, the SPE C preparation used in those experiments was contaminated with Ampholines. As an alternative to Ampholines, we used simple buffers to generate the isoelectric focusing pH gradient and used this SPE C in a comparative study to evaluate the effects of Ampholine contamination on the biological and biochemical properties of this toxin. We found that Ampholine contamination overestimates protein concentration; consequently, the biological activity of SPE C was actually greater than reported. The most serious effect of Ampholines in SPE C was on amino acid analysis. The presence of Ampholines causes an apparent increase in neutral amino acids and a decrease in basic amino acids.
Possible Chemotaxis of Human Monocytes by
N
-Acetylmuramyl-
l
-Alanyl-
d
-Isoglutamine
Authors: Ogawa Tomohiko , Kotani Shozo , Kusumoto Shoichi , Shiba Tetsuo
Published: January 2020

N
-Acetylmuramyl-
l
-alanyl-
d
-isoglutamine (MDP) induced the chemotaxis of human blood monocytes without mediation of serum complement. Specificity (dependency on chemical structure) of the chemotactic activity of MDP was evidenced by a negligible activity of analogs lacking most of the immunomodulating activities of MDP.
Serotype-Specific Protection Against
Treponema hyodysenteriae
Infection in Ligated Colonic Loops of Pigs Recovered from Swine Dysentery
Authors: Joens L. A. , Whipp S. C. , Glock R. D. , Neussen Mary E.
Published: January 2020

Resistance to
Treponema hyodysenteriae
(serotypes 1, 2, 3, and 4) infection was evaluated in ligated colonic loops in pigs recovered from swine dysentery. Lesions were present in most loops from recovered swine inoculated with heterologous serotypes; however, lesions were not present in loops of recovered swine inoculated with homologous serotypes.
Lipid A in anaerobic bacteria
Authors: Dahlén G , Mattsby-Baltzer I
Published: January 2020

The ability of lipid A preparations from strains of Bacteroides, Fusobacterium, and Veillonella to inhibit the lipid A-anti-lipid A reaction in an enzyme-linked immunosorbent assay was tested. Anti-lipid A serum was prepared with lipid A from Salmonella minnesota R595, and lipid A from Escherichia coli EH100 was used as control antigen. Preparations from three of four different species of Bacteroides were unable to inhibit the anti-lipid A activity, whereas lipid A preparations from Fusobacterium and Veillonella strains inhibited 50% of the activity at 1 to 141 micrograms. One of the Bacteroides strains, Bacteroides oralis, showed a very weak inhibiting activity at the highest concentration used. The results confirm that Bacteroides species have a unique lipopolysaccharide structure, in contrast to other anaerobic genera which have a lipopolysaccharide structure similar to that of the Enterobacteriaceae.
Additive Effects of Acyclovir and Immune Transfer in Neonatal Herpes Simplex Virus Infection in Mice
Authors: Kohl Steve
Published: January 2020

Acyclovir had a dose-dependent, mild, but significant, inhibitory effect on interferon-stimulated human antiviral natural killer cytotoxicity in vitro. In a murine model of neonatal herpes simplex virus infection, acyclovir significantly (
P
< 0.05) increased survival afforded by the injection of human interferon and human mononuclear leukocytes from 67.8 to 88.6%.
Differential Susceptibility of Chlamydiae to Exogenous Fibroblast Interferon
Authors: Byrne Gerald I. , Rothermel Constance D.
Published: January 2020

Mouse fibroblasts (L cells) were incubated for 5 h with 1,000 U of murine fibroblast interferon (MuIFN α+ β) per ml and then were infected with either
Chlamydia trachomatis
(LGV 440),
C. psittaci
(6BC), or
C. psittaci
(Cal 10). Intracellular development of
C. trachomatis
was reduced 90% in interferon-treated cells 24 h after infection when compared with controls, whereas
C. psittaci
growth was not affected in interferon-treated cells.
Delayed hypersensitivity to nonviable Mycoplasma pulmonis in mice is enhanced by dextran sulfate
Authors: Kishima M , Kuniyasu C , Nakagawa M
Published: January 2020

The enhancing effect of dextran sulfate (DS) on delayed hypersensitivity to nonviable Mycoplasma pulmonis in mice was evaluated by means of delayed footpad swelling. Mice pretreated subcutaneously with nonviable M. pulmonis and DS had significantly increased delayed footpad swelling when the mice were injected subcutaneously in the footpad with the same antigen 7 days later. Delayed footpad swelling was not detected in mice pretreated only with nonviable M. pulmonis or DS followed by footpad injection with nonviable M. pulmonis. Subcutaneous pretreatment in the scruff of the neck with nonviable M. pulmonis and DS was more effective in eliciting delayed footpad swelling than intravenous or intraperitoneal pretreatment. Delayed footpad swelling did not develop when mice were injected in the footpad with nonviable Mycoplasma hyopneumoniae, M. gallisepticum, M. dispar, or M. bovis on day 7 after pretreatment with M. pulmonis and DS. Injection of nonviable M. pulmonis in the footpad on day 3 after pretreatment with M. pulmonis and DS resulted in no significant footpad swelling, but injection in the footpad on days 7, 14, 21, and 28 resulted in significant footpad swelling. Delayed footpad swelling was transferred by intravenous injection with spleen cells of mice which were pretreated with nonviable M. pulmonis and DS into nontreated recipient mice. Intravenous injection with anti-mouse thymus cell rabbit serum into the mice which were previously pretreated with nonviable M. pulmonis and DS reduced the delayed footpad swelling significantly.
Immunization of swine with heat-stable Escherichia coli enterotoxin coupled to a carrier protein does not protect suckling pigs against an Escherichia coli strain that produces heat-stable enterotoxin
Authors: Moon H W , Baetz A L , Giannella R A
Published: January 2020

Pregnant swine were immunized parenterally with purified heat-stable Escherichia coli enterotoxin that was made antigenic by coupling it to bovine immunoglobulin G. Immunized swine had high titers of antitoxin in serum and colostrum as measured by radioimmunoassay. However, the heat-stable enterotoxin neutralizing titers of the serum and colostrum from immunized swine were comparatively low. Newborn pigs suckling their immunized dams were not protected against challenge with porcine enterotoxigenic E. coli that produce heat-stable toxin but do not produce heat-labile toxin.
Studies on the catalase of Histoplasma capsulatum
Authors: Howard D H
Published: January 2020

Factors which control the levels of catalase within yeast cells of Histoplasma capsulatum were studied. Only a small fraction of the total catalase activity could be detected in whole cells. The bulk of the activity was revealed in cell-free extracts or in cells permeabilized with acetone. The formation of the enzyme was regulated by glucose and by oxygen. There were large, consistent differences in the levels of catalase among strains of H. capsulatum. The sensitivity of the strains to H2O2 toxicity also varied remarkably. Peroxidase activity could not be detected in cell-free extracts of the strains. Resistance to H2O2 did not correspond to levels of catalase. There was no obvious correlation of H2O2 sensitivity and virulence among the strains.
In vitro synthesis of Trypanosoma cruzi antigenic polypeptides
Authors: Stolf A M , Santos C L , Brentani R , Camargo M E
Published: January 2020

A ribosomal fraction of Trypanosoma cruzi was isolated with detergent lysis and differential ultracentrifugation. This ribosomal fraction directed in vitro protein synthesis, in a heterologous incorporation system (rat liver pH 5 fraction), leading to values up to 10 times higher than endogenous control. The ideal concentrations of Mg2+, K+, and ribosomal proteins and the time of incubation of the incorporation mixtures were 6 mM, 21 mM, 60 microliters, and 45 min, respectively. The product thus obtained was analyzed by fluorography after polyacrylamide-sodium dodecyl sulfate gel electrophoresis and showed the presence of many protein bands, but few bands were present in the immunoprecipitate obtained with serum from Chagas' disease patients. This product was able to react with anti-T. cruzi antibodies when submitted to an immunoenzymatic assay.
Role of antibody response helper factors in immunosuppressive effects of friend leukemia virus
Authors: Butler R C , Frier J M , Chapekar M S , Graham M O , Friedman H
Published: January 2020

The primary antibody response of BALB/c splenocytes to sheep erythrocytes in vitro was suppressed by infection with Friend leukemia virus (FLV), with the response capacity decreasing with increasing duration of infection. The acquisition of normal antibody responses was amplified by macrophage-produced antibody response helper factor(s). FLV-infected mice were treated with bacterial lipopolysaccharide to induce the release of these helper factors into the serum. Similar to the loss of antibody response capacity by their splenocytes, the FLV-infected mice progressively lost the ability to produce helper factors in response to lipopolysaccharide. In vitro cultures of FLV-infected cells also showed a depressed ability to produce helper factor activity both spontaneously and in response to lipopolysaccharide stimulation. The reconstitution of normal levels of exogenous helper factors to FLV-infected splenocytes restored the antibody response to normal or even elevated levels. These studies indicate that the mechanism for suppression of antibody responses by FLV involves the depression of antibody response helper factor production.
Specific Inactivation of the Fourth Complement Component I. In Vivo Studies
Authors: Jensen Joerg A. , Garces Mary C. , Iglesias Elena
Published: January 2020

Intravascular injection of guinea pigs with the fourth complement component (C4) inactivator from shark serum resulted in severe serum C4 depletion that lasted for several hours. Active and direct passive Arthus reactions did not develop or were extremely mild in such C4 inactivator-treated animals as judged by gross and histological observation. In consideration of the specificity of the C4 inactivator, its independence of cofactors, and its failure to generate biologically active materials in the process of C4 inactivation, it is concluded that complement-dependent immune injury can be suppressed or avoided by interruption of the complement cascade at a single early step. The depression of the Arthus reaction beyond the time of C4 recovery prompted quantitative speculations concerning (i) the in vivo rate of C5a generation under conditions of limited C4 supply and (ii) the “saturation” of immune complexes. This view is supported by in vitro demonstration of functional inactivation or “saturation” of immune precipitates by repeated incubation with fresh guinea pig complement. It seems therefore conceivable that even temporary complement inactivation may have a profound beneficial effect on complement-dependent immune injuries.
Complement-Fixing Antigens in Burkitt Lymphoma Cell Lines
Authors: McCormick Kenneth J. , Stenback Wayne A. , Mumford David M. , Trentin John J.
Published: January 2020

The complement-fixing (CF) activity of antigens from cultured Burkitt lymphoma cells was determined by using normal American sera as the source of antibody. Approximately 75% of the sera fixed complement with the positive cell lines. These lines contained the herpes-like virus detectable by electron microscopy. The content of CF antigen depended on the cell line used but appeared to be independent of the number of cells which produced Henle's immunofluorescence (IF) antigen. Only sera that reacted in the IF test also contained CF antibodies to the crude cell extracts.
Production of Extracellular Enzymes and Enterotoxins A, B, and C by
Staphylococcus aureus
Authors: Jarvis Audrey W. , Lawrence R. C.
Published: January 2020

Eighty-seven strains of
Staphylococcus aureus
were examined for their ability to produce enterotoxins A, B, and C, deoxyribonuclease, lysozyme, proteinase, lipase, and α-, β-, and δ-hemolysins. Enterotoxigenic strains showed a significant tendency to be high lipase producers, but none of the other enzymes formed were correlated with the ability of the staphylococci to produce enterotoxins A, B, or C. The conversion of ent
−
to ent
+
strains by lysogenization did not affect significantly the ability of the strains to produce any of the above extracellular enzymes. The formation of enzymes such as deoxyribonuclease and lysozyme by staphylococci is not therefore an indication, necessarily, of their potential enterotoxigenicity.
Bactericidal Antibody Response in the Pacific Hagfish,
Eptatretus stoutii
Authors: Acton Ronald T. , Weinheimer Peter F. , Hildemann W. H. , Evans E. Edward
Published: January 2020

The hagfish,
Eptatretus stoutii
, has been shown to synthesize bactericidal antibodies after injections of gram-negative organisms. These bactericidins could be detected as early as 2 days after the primary injection. Secondary responses were accelerated, although titers were not significantly higher than those reached in the primary response. The bactericidins of hagfish were found to react with other gramnegative enteric bacteria, but not with gram-positive strains. The bactericidins show a lesser degree of specificity and a shorter induction period than other hagfish antibodies or most antibodies induced in higher vertebrates. The bactericidal activity was temperature dependent and could be irreversibly destroyed by heating at 50 C for 20 min. Immune sera were subjected to gel filtration on Sephadex G-200, and bactericidal activity was found to be associated with the excluded peak indicating a high-molecular-weight component. Evidence indicates that inducible immune responses of this bactericidal type represent a primitive capacity which arose before the emergence of vertebrate species.
Differential Action of a Streptococcal Bacteriocin on Mycoplasmas and Microbial L-Forms
Authors: Harwick H. J. , Montgomerie J. Z. , Kalmanson G. M. , Hubert E. G. , Potter C. S. , Guze L. B.
Published: January 2020

Bacteriocin activity of
Streptococcus faecalis
var.
zymogenes
was tested against a variety of bacteria, L-forms, and mycoplasmas. Both a partially purified liquid preparation and a colony overlay technique were used. Other
S. faecalis
strains were the only bacteria whose growth was inhibited. The liquid preparation inhibited growth of all but three of the tested L-forms (whether derived from gram-positive or gram-negative bacteria), and two of these exceptional organisms were inhibited when the colony overlay technique was employed. On the other hand, the L-form of
Streptobacillus moniliformis
and all 33 tested mycoplasmas grew readily in the presence of the bacteriocin when either method was employed. It is suggested that the presence of cholesterol in the
Streptobacillus
and mycoplasmal membranes, unique in this regard among procaryotic cells, may be responsible for the differential pattern of growth inhibition.
Media Exchange Method for Demonstrating Killing of L-Phase Variants in Solid Media by Normal Human Serum
Authors: McGee Zell A. , Ratner Hilda B. , Koenig M. Glenn
Published: January 2020

Normal human serum has been shown to kill L-phase variants in a fluid system by the action of antibody plus complement. Previous studies, however, failed to demonstrate such killing in solid media. This failure probably resulted from inhibition of complement by medium components such as agar and NaCl. A method was developed which circumvents the problems of the anticomplementary properties of agar media and the requirement of some L-phase variants for concentrations of salt that inhibit complement. Using this method, we have demonstrated in solid media the killing by normal human serum of the L-phase variants of
Staphylococcus aureus, Proteus mirabilis, Streptococcus pyogenes, S. faecalis, Pseudomonas aeruginosa
, and
Salmonella typhi.
This method provides a relatively simple and graphic means for studying host humoral factors lethal for L-phase variants.
Effect of β-3-Thienylalanine on Antibody Synthesis V. Immunosuppression in Mice by Short Diet and Drug Treatments
Authors: Misefari Aldo , La Via Mariano F.
Published: January 2020

The analogue of phenylalanine, β-3-thienylalanine, depresses severely the primary and secondary immune response to sheep erythrocytes in mice when administered for a few days immediately before and after each injection of antigen. For this immunosuppression to occur, animals must be maintained on a phenylalanine-free diet during the times of drug injection since dietary phenylalanine will restore anamnestic response. With these experimental conditions, the number of direct and indirect plaque-forming cells is greatly reduced during immune responses. The finding that marked immunosuppression can be obtained with a very short drug and diet treatment points to a potential usefullness of the analogue as a powerful immunosuppressant.
Chronic Proliferative Arthritis of Mice Induced by
Mycoplasma arthritidis
II. Serological Responses of the Host and Effect of Vaccines
Authors: Cole B. C. , Ward J. R. , Golightly-Rowland L. , Trapp G. A.
Published: January 2020

Complement-fixing antibodies were first detected in mice 7 days after intravenous injection with
Mycoplasma arthritidis
. Peak titers were observed at 21 days, and high levels of antibody persisted through 293 days. The metabolism-inhibiting antibody response was minimal. On fractionation of mouse sera, only 7
S
antibody was detected which first appeared at 12 days after injection and persisted throughout the experiment. In contrast, serum taken from rats injected with
M. arthritidis
contained predominantly 19
S
antibodies in the early stages of the disease which were gradually replaced with 7
S
antibodies. The intravenous injection of mice with
M. arthritidis
culture supernatant fluid had no effect upon their subsequent susceptibility to the arthritogenic effects of
M. arthritidis
, but this procedure appeared to delay the onset of abscess formation after the subcutaneous injection of
M. arthritidis
. Formalin-killed cells of
M. arthritidis
partially protected mice against the arthritis induced by
M. arthritidis
. Previous infections with
M. arthritidis
conferred partial immunity against the arthritogenic effects of the organism. Serum taken from convalescent mice at 41 days had a partial protective effect when used to immunize passively normal mice against
M. arthritidis
. However, rabbit anti-
M. arthritidis
serum which possessed higher complement-fixing and metabolism-inhibiting antibodies was without significant protective properties.
Effect of Progesterone and Testosterone on Interferon Production and on the Viral Infection-Enhancing Activity of Estrone and Hydrocortisone
Authors: Giron David J. , Schmidt Jerome P. , Pindak Frank F.
Published: January 2020

The effect of progesterone and testosterone on interferon production and on the viral infection-enhancing (VIE) activity of estrone and hydrocortisone was investigated. Neither hormone interfered with interferon production. Progesterone reduced the VIE activity of estrone but not that of hydrocortisone. Testosterone had no effect on the VIE activity of either hormone. It is concluded that the lack of VIE activity by progesterone and testosterone may be related to their inabilities to suppress interferon production. The interference by progesterone with the VIE activity of estrone suggests that, in this system, the two hormones may affect common target cells.
Response of Interferon-Treated Cells to Diphtheria Toxin
Authors: Moehring Thomas J. , Moehring Joan M. , Stinebring Warren R.
Published: January 2020

It has been reported that treatment with homologous interferon of cells in culture interferes with the process of diphtheria intoxication in these cells. This report both confirms and extends this observation. The most sensitive indicator of diphtheria toxin action in cells, i.e., the inhibition of incorporation of labeled amino acids into protein, was employed, and human, mouse, and chicken interferon-cell systems were studied. Interferon treatment afforded a distinct, reproducible protection from the action of toxin, but in no case could total protection be shown. The “antitoxic” component is stable at
p
H 2, is species-specific, is not sedimented at 100,000 ×
g
, and is trypsin-sensitive. Human cell preparations are heat-labile. Experiments with cell-free amino acid incorporation systems suggest that the “anti-toxic” effect of interferon is concentrated at the level of the cell membrane and subcellular components are not directly involved.
Protective Role of Smooth Lipopolysaccharide in the Serum Bactericidal Reaction
Authors: Reynolds B. L. , Pruul H.
Published: January 2020

The mechanism by which smooth lipopolysaccharide (LPS) protects
Salmonella typhimurium
C5 from the lethal action of specific antibody and complement has been investigated. Tris(hydroxymethyl)aminomethane (Tris) and ethylenediaminetetraacetate (EDTA), which sensitize
S. typhimurium
C5 to the bactericidal action of immune serum, were shown to cause appreciable structural modification of the smooth LPS associated with these cells. Mg
2+
was shown to reverse the sensitization of C5 by Tris, but this divalent cation was unable to reverse the sensitizing effect of Tris plus EDTA, which, unlike Tris, caused relatively large amounts of O-antigenic components to be released from the C5 cell wall. The possibility that smooth LPS blocks the interaction of activated complement components with receptors on the cell wall is discussed.