bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental scrub typhus immunogens: gamma-irradiated and formalinized rickettsiae
Authors: Eisenberg G H , Osterman J V
Published: January 2020

Scrub typhus immunogens were prepared by exposing infected yolk sac suspensions of Rickettsia tsutsugamushi to various doses of gamma radiation. Mouse lethality was abolished at doses greater than 200 krads, whereas immunogenicity of the suspensions, as shown by mouse protection tests, was diminished relatively little by radiation doses in the 200- to 400-krad range. Using a 300-krad gamma dose to provide a safety factor, immunogens were prepared and their protective capacity was contrasted with formalinized scrub typhus immunogens prepared by conventional techniques. Formalinized suspensions afforded mice only partial protection against intraperitoneal challenge with 1,000 50% mouse lethal doses of the virulent homologous strain and no significant protection against similar challenge with an equally virulent heterologous strain. Using the same strains, radiation-inactivated preparations provided 100% protection against 10,000 50% mouse lethal doses of the homologous strain and 70% protection against challenge with the same doses of a heterologous strain. Neither immunogen was a potent stimulator of antibody production as measured by the complement-fixation test. Cell-transfer studies using inbred mice indicated a role for cell-mediated immunity after vaccination with gamma-irradiated immunogens, but no cell-mediated protection could be demonstrated after vaccination with formalin-inactivated rickettsiae.
Effects of pneumococcal mucopeptide and capsular polysaccharide on phagocytosis
Authors: Dhingra R K , Williams R C , Reed W P
Published: January 2020

Pneumoccal cell wall and capsular products from eight serotypes were tested for their ability to inhibit polymorphonuclear neutrophil killing of the same eight pneumococcal strains. Crude pneumococcal cell wall preparations from all serotypes inhibited phagocytic killing of several pneumococcal serotypes, and were just as effective with heterologous as with homologous strains. Phagocytosis dependent on heat-labile serum factors was inhibited, whereas phagocytosis not dependent on heat-labile factors was not significantly affected. These findings were compatible with inhibition of complement consumption. The inhibitory activity was found in a purified cell wall mucopeptide, whereas purified capsular polysaccharides failed to inhibit phagocytosis.
Effects of Low- and High-Passage Influenza Virus Infection in Normal and Nude Mice
Authors: Wyde Philip R. , Couch Robert B. , Mackler Bruce F. , Cate Thomas R. , Levy Barnet M.
Published: January 2020

A human isolate of type A Hong Kong influenza virus (H3N2) was adapted to mice by serial passage. Lung homogenates from mice who received low passage levels contained about the same quantity of virus (10
6.2−6.95
50% tissue culture infective doses/ml) as those from mice who received high passage levels (10
5.95−6.45
50% tissue culture infective doses/ml); however, death occurred only in animals given high-passage virus. Passage 3 (P3) and passage 9 (P9) viruses were selected as representative of low-passage and high-passage viruses, respectively. Although minimal differences were detected in infectivity for rhesus monkey kidney tissue cultures and mice, P9 virus was at least 10,000 times more lethal for mice (mean lethal dose = 10
4.2
). Infection with P3 virus was accompanied by minimal bronchitis and bronchiolitis only, whereas P9-infected animals exhibited marked bronchitis, bronchiolitis, and pneumonia. Striking thymic cortical atrophy was also demonstrable in the P9-infected animals and, although virus was more commonly recovered from thymuses from these animals, immunofluorescent studies revealed only a few cells containing influenza virus antigens. To further explore the participation of thymus-derived lymphocytes in influenza, athymic nude mice and furred immunocompetent littermates were given 500 50% mouse infectious doses of P9 virus. Nude mice exhibited an increased survival time and, in contrast to the extensive lung pathology seen in furred littermates, manifested minimal cellular infiltration and no tissue destruction in lungs. Brains from nude mice exhibited encephalomalacia with lymphocytic perivascular cuffing, which was not seen in furred animals. Virus was recovered from brains of 6 of 13 nude mice and 1 of 10 furred animals. The contrasting models suggest that thymus-dependent cells play a significant role in the inflammatory response to influenza virus infection and should prove useful for probing host-virus interactions which characterize influenza virus virulence.
Determination of molecular weight, isoelectric point, and glycoprotein moiety for the principal skin test-reactive component of histoplasmin
Authors: Sprouse R F
Published: January 2020

A purified component designated HPD (histoplasmin-purified derivative) dII was isolated from two different cru-e histoplasmin lots by a combination of gel filtration and polyacrylamide disc electrophoresis (Sprouse, 1969). A 0.05-mug portion of HPD dII was reactive and specific in detection of delayed hypersensitivity in guinea pigs experimentally infected with Histoplasma capsulatum. The objective of this study was to characterize this skin test-reactive component for (i) homogeneity, (ii) molecular weight, (iii) isoelectric point, and (iv) composition. Sephadex chromatography, polyacrylamide disc electrophoresis, sucrose density gradient ultracentrifugation, acid and heat denaturation, and immunoelectrophoresis indicate that HPD dII is (i) homogeneous, (ii) of approximately 12,000 molecular weight, and (iii) a glycopeptide of approximately 60% carbohydrate and 40% proteinaceous composition. The marked acid and heat stability exhibited by the compound probably is attributable to the prominent carbohydrate moiety in the molecule. Isoelectric focusing indicated an isoelectric point of 5.68. This would suggest that dII is an acidic compound with either predominance of acidic amino acid residues in the molecule or, more probably, an abundance of electron donors in the carbohydrate moiety. In summary, HPD dII appears to be a glycopeptide of approximately 12,000 molecular weight, reactive in elicitation of delayed hypersensitivity of histoplasmosis.
Inhibition of glucosyltransferase by human salivary immunoglobulin A
Authors: Klein J P , Schöller M , Frank R M
Published: January 2020

Purified glucosyltransferase isolated from Streptococcus sanguis OMZ 9 and different immunoglobulin A from saliva, saliva pellet, and dental plaque were used to study enzyme-antibody interactions. A strong inhibition of glucosyltransferase activity was obtained with the different immunoglobulin A fractions.
Interactions between mycoplasma pneumoniae and the first components of complement
Authors: Bredt W , Wellek B , Brunner H , Loos M
Published: January 2020

Mycoplasma pneumoniae cells were rounded and killed by fresh guinea pig serum (GPS) which did not contain detectable amounts of antibody. The first component of complement (C1) was bound by M. pneumoniae in considerable amounts from both GPS and purified C1. The C1 bound by the cells was reacting with C4. Sequential addition of C1, C4, C2, and C-ethylenediaminetetraacetate to glass-grown M. pneumoniae cells resulted in rounding of a significant number of cells. M. orale and M. fermentans showed a reduced binding capacity for C1 as compared with M. pneumoniae. Both species were only slowly killed by fresh GPS, whereas M. hominis was as sensitive as M. pneumoniae. The results suggest an antibody-independent interaction between some components of the membrane surface of M. pneumoniae and C1, resulting in an activation of the complement system leading to the killing of the mycoplasma cells.
Increased histamine sensitivity in mice after administration of endotoxins
Authors: Bergman R K , Munoz J J
Published: January 2020

CFW mice given submicrogram doses of endotoxins intravenously became highly susceptible to the lethal effects of 0.5 mg of histamine given intraperitoneally 1 to 2 h later. The histamine-sensitizing effects of the endotoxins were transitory and disappeared within 6 to 8 h. L-Epinephrine administered intravenously immediately after histamine challenge protected mice from death, but aterenol and isoproterenol were ineffective. The histamine-sensitizing effect in endotoxins was precipitated by anti-endotoxin sera with a concomitant eightfold loss in activity. However, dissociation of the immune complex in 0.25 M acetic acid fully restored histamine-sensitizing activity. The transitory nature of the hypersensitivity produced by endotoxin and the high heat resistance of the active material prove that it is different from the histamine-sensitizing effects of pertussigen.
Long-term studies on rhesus monkeys (Macaca mulatta) immunized against Plasmodium knowlesi
Authors: Cabrera E J , Barr M L , Silverman P H
Published: January 2020

Studies carried out on four rhesus monkeys (Macaca mulatta) that had been vaccinated against Plasmodium knowlesi show that the immunized animals were protected against a challenge with a heterologous strain of P. knowlesi. This protection was shown to be present even 4 years after the immunization schedule has been completed. The effect could not be attributed toprevious infections with the parasite, since four control rhesus monkeys that had recovered from one to four challenges with P. knowlesi died when exposed to the heterologous strain. Data obtained from the lymphocyte transformation test and the radioimmunoassay are also presented.
Improved minca medium for the detection of K99 antigen in calf enterotoxigenic strains of Escherichia coli
Authors: Guinée P A , Veldkamp J , Jansen W H
Published: January 2020

The K99 antigen of Escherichia coli can be detected more readily in cultures grown on Minca medium at 37 degrees C for 6 to 8 h or grown on Minca plus 1% Iso VitaleX for 20 to 24 h.
Intestinal fluid accumulation induced by oral challenge with Vibrio cholerae or cholera toxin in infant mice
Authors: Baselski V , Briggs R , Parker C
Published: January 2020

The diarrheal response of orally inoculated infant mice to viable Vibrio cholerae and purified cholera toxin was quantitated by means of a fluid accumulation (FA) ratio. The FA ratio is defined as the gut weight/remaining body weight. FA ratios were determined in relation to time of exposure and dose. Onset of fluid accumulation with viable cells of strains CA401 and 569B occurred 8 h postinoculation and reached a near maximum of 16 h. A dose of 4 x 10(6) colony-forming units of strain CA401 was required for a positive response 16 to 18 h postinoculation. Several other classical cholera strains demonstrated a similar dose-related response. Strain 569B, however, required a 100-fold higher dose to give a positive response. Several mutant cholera strains were decreased virulence in other model systems elicited FA ratios decreased from wild-type values. Onset of fluid accumulation which cholera toxin occurred 6 to 8 h postinoculation and reached a maximum by 10 h. A dose of 0.5 microng was required for a positive response 10 to 12 h postinoculation. The positive response to toxin could be inhibited by preincubation with specific antitoxin.
Effect of protein A on staphylococcal opsonization
Authors: Peterson P K , Verhoef J , Sabath L D , Quie P G
Published: January 2020

To study the effect of wall protein A on bacterial opsonization, phagocytosis of 10 strains of Staphylococcus aureus with high and low protein A contents was measured. Those strains that contained the highest concentrations of protein A were phagocytized by human neutrophils at a slower rate than strains with little or no protein A when normal human serum and purified immunoglobulin G (IgG) were used as opsonic sources. When IgG-deficient serum was used as an source, however, protein A-rich strains were phagocytized more rapidly than protein A-deficient strains. Extracellular (purified) protein A decrease the opsonic activity of all sera tested including IgG-deficient serum. It is proposed that when IgG is not present in the opsonic medium, cell wall protein A is capable of activating complement at the bacterial surface and thereby opsonization is promoted.
Indirect immunofluorescence antibodies in natural and acquired Rickettsia tsutsugamushi infections of Philippine rodents
Authors: Van Peenen P F , Ho C M , Bourgeois A L
Published: January 2020

Antibodies against Rickettsia tsutsugamushi detected by the indirect fluorescent-antibody test (IFAT) were present in most rats trapped from a human focus of scrub typhus in the Philippines. Rickettsiae were isolated only from rats with positive IFATs. Naturally acquired antibodies persisted for at least 11 months, and antibodies resulting from experimental infections of rats persisted for at least 7 months. A common Philippine rodent, Rattus mindanensis, tolerated experimental infections with both local and standard Karp strains of R. tsutsugamushi, and such infections always produced a positive IFAT.
Ultrastructural investigations on surface structures involved in Coxiella burnetii phase variation
Authors: Krauss H , Schiefer H G , Schmatz H D
Published: January 2020

By using the cytochemical staining procedure with concanavalin A, horseradish peroxidase, and diaminobenzidine, no surface carbohydrates with terminal alpha-glucosyl or sterically closely related residues could be detected on the cell walls of Coxiella burnetii phases I and II. Using a polycationized ferritin derivative as a cytochemical probe, anionic binding sites were visualized in the electron microscope on cell membranes of C. burnetii phase II, but not on phase I organisms. The sites appeared to be masked in phase I particles. Anionic sites could be demonstrated on phase I organisms after treatment with NaIO4 or dimethyl sulfoxide. A number of different biological properties of C. burnetii phases I and II may depend on the presence or absence of a net negative charge on the surface of the cell walls of these organisms.
Effect of Clostridium perfrongens enterotoxin in mitochondrial respiration
Authors: McDonel J L , Duncan C L
Published: January 2020

Clostridium perfringens enterotoxin caused a 26 to 41% reduction in the rate of oxygen consumption by rat liver mitochondria when various tricarboxylic acid cycle intermediates were used as substrate. However, P/O ratios were unaltered.
Comparison of ethyleneglycoltetraacetic acid and its magnesium salt as reagents for studying alternative complement pathway function
Authors: Fine D P
Published: January 2020

The divalent cation chelators, ethyleneglycoltetraacetic acid (EGTA) and its magnesium salt, MgEGTA, were compared in studies of alternative complement pathway function. EGTA (0.01 M) inhibited both the rate and the amount of complement activation by zymosan whether compared to nonchelated serum or to serum chelated with MgEGTA (0.01 M). The rate of alternative pathway activation by zymosan was slightly slower in MgEGTA-chelated serum than in nonchelated serum, but the overall amount of complement consumed by a given amount of zymosan was not decreased. MgEGTA chelation spontaneously activated the alternative pathway, as reflected by lysis of erythrocytes from a patient with paroxysmal nocturnal hemoglobinuria. No evidence could be found that MgEGTA either spontaneously activated C2 or facilitated zymosan activation of C2. Suggested guidelines for the use of these chelators are advanced.
Comparative Effects of Host and Viral Factors on Early Pathogenesis of Marek's Disease
Authors: Fabricant J. , Ianconescu M. , Calnek B. W.
Published: January 2020

A series of experiments on the early pathogenesis of Marek's disease was conducted according to a uniform scheme. In each experiment, there was a single variable-age, genetic strain, or virus strain. Virus assays from spleen, buffy coat, and bone marrow, and fluorescent antibody tests on spleen, bursa of Fabricius, and thymus were conducted on five birds per group daily from the 3rd through the 10th day postinoculation. From these data, it was apparent that the response could be divided into two periods: 4 to 6 days = early; 8 to 10 days = late. Serological tests showed all groups except the 1-day-old group to have neutralizing antibody by the end of the 10-day period. With few exceptions, none of the variables tested exerted any appreciable influence on the level of virus growth in spleen, bursa, or thymus during the early period. High levels of infection occurred in all birds during that period. Changes in infection pattern which occurred during the late period were significant and could be correlated with occurrence of Marek's disease in test samples of birds held until 7 weeks after infection. Infectivity levels dropped appreciably in the case of resistant N-line birds given JM virus, and, during the late period, infection levels were significantly higher in GA-infected birds than in those given viruses of lower virulence. Whereas the virus titers during the 8- to 10-day period usually reflected the eventual clinical pattern of Marek's disease, the levels of viral antigen (fluorescent antibody tests) were much less consistent. One further experiment conducted by the same uniform scheme demonstrated no significant effects on early pathogenesis or course of Marek's disease in birds given continuous oral medication with amino-ureido-sulfone.
Protective role of complement in experimental Escherichia coli endocarditis
Authors: Durack D T , Beeson P B
Published: January 2020

Fourteen strains of Escherichia coli were tested for ability to cause infective endocarditis in rabbits prepared by prior placement of an intracardiac catheter. Strains that were resistant to the bactericidal action of serum caused E. coli endocarditis in 91.4% of rabbits, whereas serum-sensitive strains usually failed to cause persisting infection (11.3% infected, P less than 0.001). Although serum-sensitive E. coli lodged on heart valves within 1 h after intravenous injection, they survived less than 24 h in most normal rabbits. In contrast to normals, all five C6-deficient rabbits injected with a serum-sensitive strain of E. coli developed infective endocarditis (P less than 0.005). No correlation was found between the presence of K1 antigen and the incidence of experimental E. coli endocarditis. Thus, the ability of strains of E. coli to establish persisting endocardial infection in rabbits appears to be directly associated with resistance to the complement-mediated serum bactericidal system. These findings may explain in part the rarity of gram-negative bacillary endocarditis in patients; they also indicate that in certain special circumstances the serum bactericidal system can play a decisive role in host defense.
Immunology of the infant rat experimental model of Haemophilus influenzae type b meningitis
Authors: Myerowitz R L , Norden C W
Published: January 2020

The age-related acquisition of serum anticapsular and bactericidal antibodies to Haemophilus influenzae type b observed in rats was similar to that of humans. The antigenic source for this "natural" immunity was not identified since neither pharyngeal infection with H. influenzae b nor enteric colonization by cross-reacting bacteria was detected. Infant rats surviving H. influenzae b bacteremia failed to respond immunologically to the capsular polysaccharide. However, surviving rats demonstrated no impairment of immune responsiveness to this antigen after subsequent immunization with live bacteria in adulthood. In passive protection experiments, antibodies directed against the type b capsular polysaccharide represented the major protective specificity. However, a small protective effect of antibodies to noncapsular antigens also appeared to have been demonstrated.
Colonization of porcine intestine by enterotoxigenic Escherichia coli: selection of piliated forms in vivo, adhesion of piliated forms to epithelial cells in vitro, and incidence of a pilus antigen among porcine enteropathogenic E. coli
Authors: Nagy B , Moon H W , Isaacson R E
Published: January 2020

In contrast to K88-positive porcine enterotoxigenic Escherichia coli (ETEC), K88-negative porcine ETEC strains did not adhere to isolated intestinal epithelial cells in vitro. However, they did adhere to intestinal epithelium in vivo. Growth of one such ETEC (strain 987) in pig small intestine consistently yielded a greater percentage of piliated cells than did growth in vitro. This increase was demonstrable by electron microscopy, by change in colonial morphology, and by agglutination in specific antisera against the pili of strain 987. In contrast to the stored stock culture (which contained very few piliated cells), richly piliated forms of strain 987 did adhere to isolated intestinal epithelial cells in vitro. A series of porcine E. coli strains was tested for agglutinability in antiserum against the pili of strain 987, and several K88-negative ETEC strains were agglutinated. These data are consistent with the hypothesis that pili facilitate intestinal adhesion and colonization by K88-negative ETEC strains.
Pathogenesis of latent herpes simplex virus infection of the trigeminal ganglion in guinea pigs: effects of age, passive immunization, and hydrocortisone
Authors: Tenser R B , Hsiung G D
Published: January 2020

Latent herpes simplex virus (HSV) infection of the trigeminal ganglion, after corneal inoculation of virus, was investigated in guinea pigs. The effects of several factors on the establishment of ganglionic latency were investigated. Latently infected guinea pigs were clinically normal, and virus was isolated from the trigeminal ganglia by co-cultivation. It was found that newborn guinea pigs were significantly more susceptible than adult animals to the development of latent HSV infection of the trigeminal ganglion. The susceptibility of newborn guinea pigs was very much decreased, however, if they received passive immunization with immune serum or if they were born of actively immunized mothers. On the other hand, the susceptibility of adult animals, usually somewhat resistant to the development of latent HSV ganglionic infection, was markedly increased by the parenteral administration of hydrocortisone.
Non-encapsulated variant of Cryptococcus neoformans. II. Surface receptors for cryptococcal polysaccharide and their role in inhibition of phagocytosis by polysaccharide
Authors: Kozel T R
Published: January 2020

The binding of cryptococcal polysaccharide to a non-encapsulated strain of Cryptococcus neoformans was studied. Binding of purified polysaccharide to the yeast was determined by inhibition of phagocytosis and by indirect immunofluorescence techniques. The ability of cryptococcal polysaccharide to prevent phagocytosis of the non-encapsulated strain appears to be directly related to adherence of polysaccharide to the yeast via specific receptors on the cell surface. Addition of varying doses of cryptococcal polysaccharide to non-encapsulated yeast cells inhibited phagocytosis only at polysaccharide concentrations at which the polysaccharide could be demonstrated on the yeast surface by immunofluorescence. Macrophages treated with cryptococcal polysaccharide had no detectable amounts of cryptococcal polysaccharide adherent to their surface, and they had a normal ability to phagocytize the yeast. Kinetic studies showed that inhibition of phagocytosis is directly related to the presence of cryptococcal polysaccharide at the yeast surface rather than to some indirect effect by the polysaccharide on serum components necessary for phagocytosis. Purified polysaccharide from C. neoformans serotypes A, B, C, and D bound to the yeast, but type III pneumococcal polysaccharide did not inhibit phagocytosis of the nonencapsulated yeast. Cryptococcal polysaccharide did not bind to cells of Candida albicans, C. pseudotropicalis, Torulopsis sp., Rhodotorula sp., or Saccharomyces cerevisiae.
Comparative study of three methods for detecting avian leukosis viruses
Authors: Smith E J , Crittenden L B , Ignjatovic J
Published: January 2020

This investigation was designed to compare detection limits for avian leukosis viruses after infection of chicken fibroblasts with decimal dilutions of Rous-associated virus type 1 (RAV-1). At 5, 9, 14, and 19 days postinfection, cells were examined for group-specific (gs) antigens by microtiter complement-fixation (CF) tests for avian leukosis viruses and by radioimmunoassays (RIA) for the major gs antigen having a molecular weight of 27,000 (p27). Culture fluids, collected at the same time periods, were also assayed for reverse transcriptase activities. We found that minimally infected cultures expressed virus proteins within 9 days postinfection regardless of method used. Although p27 RIA was consistently more sensitive than CF or reverse transcriptase assays, sensitivity was only two- to fivefold greater when concentrated suspensions of RAV-0, RAV-1, and RAV-2 were compared. In terms of infectious units, the lowest detectable virus titer was 6 X 10(3) infectious units as determined by RIA end point dilutions. However, our results led us to conclude that when concentrated cell extracts are tested with hamster antiserum, CF is adequate for detecting infection.
Cell-mediated immunity after oral immunization with ribonucleic acid-protein fractions of Vibrio cholerae L-form lysates
Authors: Agarwal S C , Sundararaj T
Published: January 2020

Oral administration of a single dose of ribonucleic acid-protein fraction of lysates of Vibrio cholerae subtype Ogawa L-forms induced an increase in cell-mediated immunity in rabbits. This was demonstrated by an increase in leukocyte migration inhibition in peripheral blood leukocytes, in macrophages migration inhibition, and in microbicidal activity against Listeria monocytogenes in peritoneal macrophages obtained from orally immunized rabbits. Increased cell-mediated immunity was induced mainly with V. cholerae Ogawa and ribonucleic acid-protein fractions. It appeared in 20 days and persisted for at least 90 days.
Antibody-dependent cellular protection against herpes simplex virus dissemination as revealed by viral plauqe and infectivity assays
Authors: Shimizu F , Hanaumi K , Shimizu Y , Kumagai K
Published: January 2020

Mouse nonimmune peripheral blood lymphocytes (PBL) plus antibody to herpes simplex virus inhibited virus dissemination in herpes simplex virus-infected 3T3 cell culture as revealed by development of viral plaque, size of immunofluorescent foci, appearance of polycaryocytes, and viral infectivity appearing in the culture. These nonimmune PBL did not act alone in inibiting virus dissemination, but did act synergistically in combination with antibody. The ratio of PBL to target monolayer cells needed to produce this effect was 20. Splenic lymphocytes had weak activity, whereas thymocytes were without effect, even in the presence of antibody. Neither interferon nor lymphotoxin was detected in this lymphocyte-mediated response. These findings support previous observations, based on cytotoxicity assays, that antibody-dependent cellular immune processes could be important in control of and recovery from herpesvirus infection.
Age-related decline in the resistance of mice to infection with intracellular pathogens
Authors: Gardner I D , Remington J S
Published: January 2020

Resistance to infection with Toxoplasma gondii and Listeria monocytogenes in BALB/c female mice decreased with increasing age. The decrease was apparent as early as 9 months of age and was more marked as the animals aged further. This age-related decline in resistance was not restricted to BALB/c female mice, as male and female mice of the C57BL/6 strain exhibited similar responses. With both pathogens, aged mice showed a more marked susceptibility to the strain of lesser virulence. Transfer of normal serum from old mice to young or old mice before infection with T. gondii resulted in an increased susceptibility to this organism, suggesting the presence of inhibitory factors or the absence of potentiating factors that are present in the serum of young mice.
Production and assay of antibodies against one antigenic component of Mycobacterium bovis BCG
Authors: Harboe M , Closs O , Svindahl K , Deverill J
Published: January 2020

Monospecific antisera against BCG antigen 60 were produced by all of four rabbits during immunization with precipitates containing antigen 60 cut out of gels after crossed immunoelectrophoresis. During electrolytic iodination of a crude antigen 60 preparation, preferential labeling of antigen 60 was demonstrated, and a specific radioimmunoassay was established to follow the development of anti-BCG-60 activity during immunization.
Interaction of inflammatory cells and oral microorganisms. IV. In vitro release of lysosomal constituents from polymorphonuclear leukocytes exposed to supragingival and subgingival bacterial plaque
Authors: Taichman N S , Tsai C C , Baehni P C , Stoller N , McArthur W P
Published: January 2020

The deposition of bacterial plaques on tooth surfaces appears to be responsible for the initiation and progression of periodontal disease. In this study, human peripheral blood polymorphonuclear leukocytes (PMNs) actively released lysosomal constituents upon in vitro exposure to either viable or irradiated, supragingival or subgingival dental plaque. Plaques were obtained from the PMN donors (autologous plaque) or from pooled samples (homologous plaque) secured from patients with periodontal lesions. Fresh sera from PMN donors amplified the release reactions to supragingival and subgingival plaques. Heated (56 degrees C, 30 min) sera also enhanced release reactions, but not as consistently as fresh serum. It was postulated that modulation of PMN release by serum is mediated by complement components and/or antibodies to plaque bacteria. Electron microscopic observations indicated that degranulation and discharge of PMN lysosomal enzymes may be associated with phagocytosis of gram-positive and gram-negative plaque bacteria and with reverse endocytosis of lysosomes from cells contacting relatively large masses of aggregated plaque bacteria. These data suggest that PMN lysosome release in response to plaque may serve as a potential mechanism of tissue injury in the pathogenesis of gingival and periodontal inflammation.
Quantitative granulocyte chemiluminescence in the rapid detection of impaired opsonization of Escherichia coli
Authors: Stevens P , Young L S
Published: January 2020

Previous work has demonstrated that 40% of clinically isolated Escherichia coli are resistant to in vitro killing by normal human polymorphonuclear granulocytes (PMN) due to ineffective opsonophagocytosis. Using these E. coli isolates, we have demonstrated the usefulness of measuring the chemiluminescence (CL) of granulocytes undergoing phagocytosis in detecting this impaired opsonization. CL correlated well with several other methods to assess PMN function including in vitro killing assays, postphagocytic O2 consumption, and morphological phagocytic indexes. Of the available methods to assess granulocyte function, CL is the most rapid and simple and would appear to be a potentially useful screening method to determine possible opsonic deficiencies of human PMNs and serum. Impaired opsonization to these resistant E. coli isolates was demonstrable in several different donors and could be reversed by type-specific rabbit antibody to the particular resistant isolate. Bacterial levels of superoxide dismutase and catalase, enzymes which have been implicated as possible virulence factors in some microorganisms, did not correlate with resistance in these E. coli isolates. However, heat denaturation of these isolates reversed this resistance and would suggest heat-labile antigenic determinants present in E. coli as possible resistance factors.
Antibody response to rabies virus in Syrian hamsters
Authors: Coe J E , Bell J F
Published: January 2020

Syrian hamsters were injected with inactivated, attenuated, and virulent rabies virus (RV), and the antibody response was quantified by a neutralization test and the immunoglobulin class of the virus antibody was characterized by indirect fluorescent microscopy. Serum antibodies to RV were found to be predominantly of the immunoglobulin G2 (IgG2) class, although IgG1 anti-RV also were detected in high-titered sera obtained after secondary challenge. Brain extracts of hamsters inoculated intracerebrally with RV contained only IgG2 anti-RV. IgA and IgM anti-RV were not detected. The preferential IgG2 response to RV is in marked contrast to the isolated IgG1 response detected after inoculation of hamsters with soluble purified protein antigens.
Functional studies on human peritoneal eosinophils
Authors: Klebanoff S J , Durack D T , Rosen H , Clark R A
Published: January 2020

A number of functional studies were performed on essentially pure eosinophil preparations obtained from the ascitic fluid of a patient with eosinophilic gastroenteritis. These cells responded to chemotactic factors including a bacterial factor, partially purified C5a, and factors generated from serum or ascitic fluid. The chemotactic activity generated in the patient's ascitic fluid was capable of attracting both neutrophils and eosinophils, was dependent on the presence of complement components, and was identified as C5a. Metabolic studies demonstrated that particle ingestion by eosinophils was associated with a marked increase in hexose monophosphate shunt activity ([1-14C]glucose oxidation), H2O2 formation ([14C]formate oxidation), superoxide anion generation, chemiluminescence, thyroid hormone degradation, iodination, and estrogen binding. This postphagocytic metabolic burst by eosinophils was qualitatively similar to that observed in neutrophils, but for several parameters the eosinophil response was greater than the neutrophil response.
Nature of the genetic determinant controlling encapsulation in Staphylococcus aureus Smith
Authors: Smith R M , Parisi J T , Vidal L , Baldwin J N
Published: January 2020

Two strains of Staphylococcus aureus, Smith and M, were studied for the elimination of encapsulation. For S. aureus M, encapsulation was stable. For S. aureus Smith, spontaneous loss of encapsulation was 1.3% and increased markedly in medium containing surface-active agents. In the presence of sodium dodecyl sulfate, unencapsulated cells had a considerable selective advantage. Attempts to demonstrate covalently closed circular plasmid deoxyribonucleic acid were unsuccessful. In cultures of unencapsulated cells, encapsulated cells were observed occasionally. These data argue against a plasmid location for the determinants controlling encapsulation in this organism in spite of a high spontaneous loss of this character.
Role of endotoxin contamination in ribiosomal vaccines prepared from Salmonella typhimurium
Authors: Misfeldt M L , Johnson W
Published: January 2020

Ribosomal vaccines prepared from Salmonella typhimurium SR-11 and 6707 an Re mutant bacterium of strain LT2, were effective immunogens in A/J and C3H/HeDub inbred mice. Only SR-11 ribosomes were able to induce significant protection in C3H/HeJ mice. C57BL/6J mice were not protected by either ribosomal preparation. A/J mice were protected against salmonella infection by purified SR-11 endotoxin preparations. Neither the C3H/HeDub, the C3H/HeJ, nor the C57BL/6J mice were protected by the endotoxin preparation. Passive hemagglutination studies showed that C3H/HeJ mice had no antibodies to O antigen but were significantly protected by SR-11 ribosomes. In contrast, C57BL/6J mice, which had the highest titers of O antibodies of the four inbred mouse strains, were not protected by SR-11 ribosomes. Endotoxin cannot totally account for the effectiveness fo ribosomal account for the effectiveness of ribosomal vaccines prepared from S. typhimurium.
Development of delayed-type hypersensitivity during Mycobacterium lepraemurium infection in mice
Authors: Poulter L W , Lefford M J
Published: January 2020

Various preparations of Mycobacterium lepraemurium were used to elicit delayed-type hypersensitivity in the footpad of mice infected with this organism. With a sonicated preparation of the mycobacterium, a significant increase in footpad swelling was elicited in mice infected with M. lepraemurium 5 weeks previously, but not in BCG-infected animals or uninfected controls. This footpad reaction was shown to peak at 24 h and to be associated with an infiltration of mononuclear cells. The kinetics of footpad swelling, its association with lymphoproliferation, and its dependence on T lymphocytes were each examined. The results support the hypothesis that this is a delayed-type hypersensitivity reaction. The ability to transfer this reactivity to normal mice with cells but not serum offers further confirmation that this hypersensitivity is dependent on cell-mediated immunological mechanisms rather than humoral antibody. The relevance of this to the study of the immunological response of mice to murine leprosy is discussed.
Inhibition of leptospiral agglutination by the type-specific main antigens of leptospiras
Authors: Adachi Y , Yanagawa R
Published: January 2020

Microscopic agglutination of leptospiras was inhibited by the homologous type-specific main antigens. The result may indicate that the substance participating in the agglutination of leptospiras with antiserum is the type-specific main antigen.
Intestinal Absorption of Botulinum Toxins of Different Molecular Sizes in Rats
Authors: Sugii Shunji , Ohishi Iwao , Sakaguchi Genji
Published: January 2020

During a period of 10 to 12 h after injection of type B 16S (L) toxin into the ligated duodenum of rats, 0.01 to 0.1% of the total toxicity administered was found in the lymph drawn by cannulation of the thoracic duct. The recovery was 50 to 100 times higher than that of the rat given type B 12S (M) or 7S (S) toxin. During the same period, 0.6 to 1.5% of the specific antigens were recovered, regardless of the molecular size of the toxin that had been administered. In lymph of the B-L or B-M toxin recipient, the toxic and nontoxic components were detected in comparable quantities, indicating that the undissociated progenitor toxin molecule is absorbed through the intestinal wall. Although the toxic component had lost its toxic activity, the two components of B-M toxin appearing in lymph reassembled to reconstruct the 12S molecule, whereas those of B-L toxin did not, although the toxic component was still active. Type B-L, B-M, and B-S toxins showed similar stabilities to in vitro exposure to rat lymph (pH 8.2), but B-L toxin showed a considerably higher stability to intestinal juice (pH 7.0) than did B-M toxin. Thus, the toxicity of lymph of rats administered botulinum toxin intraduodenally depends not upon the rate of absorption, but largely upon the stability in the intestine.
Radioimmunoassay for the Antigenic Determinants of Cholera Toxin and Its Components
Authors: Hejtmancik Kelly E. , Peterson Johnny W. , Markel Daiel E. , Kurosky Alexander
Published: January 2020

A radioimmunoassay procedure is described for the detection of cholera toxin and its component polypeptide chains. Cholera toxin, A subunit, B subunit, α chain, and γ chain were iodinated by the chloramine T procedure. Radiolabeling did not significantly alter the polyacrylamide electrophoretic migration patterns of the toxin or its components. Moreover, radiolabeled toxin, B subunit, and α chain preparations retained substantial ability to bind to intestinal mucosal homogenates. The minimal amount of antitoxin detectable with radiolabeled toxin was 0.04 antitoxin units/ml. Substitution of radiolabeled B subunit, A subunit, and α chain for radiolabeled toxin decreased the sensitivity of the test. Radiolabeled γ chain did not bind to the antitoxin preparation. Competitive inhibition studies, with titrated anti-choleragen serum and radiolabeled toxin or components, indicated that the minimum concentration of toxin detectable was 7.0 × 10
−8
μmol/ml at a 90% inhibition level. The A subunit and α chain preparations inhibited the binding of the radiolabeled B subunit to antitoxin sites. Conversely, B subunit inhibited the binding of radiolabeled A subunit and α chain to antitoxin. The γ chain did not show any reaction with antitoxin or cross-reaction with either whole toxin or its components. These results strongly suggest that the A subunit and the α chain contain antigenic determinant(s) that are common to the B subunit. The B subunit (β chain) and the α chain of cholera toxin may therefore contain region(s) of chemical similarity.
Prolonged survival of virulent Treponema pallidum (Nichols strain) in cell-free and tissue culture systems
Authors: Fieldsteel A H , Becker F A , Stout J G
Published: January 2020

Survival of Treponema pallidum was found to be prolonged in the presence of tissue culture. Of the 12 cultures studied, cottontail rabbit epithelium (Sf1Ep) supported T. pallidum for the longest time. In horizontal Leighton tubes with reduced medium and an atmosphere of 5% CO2 in N2, the 50% survival time (ST50) was 5 to 6 days for treponemes associated with monolayers of Sf1Ep cells. Comparable cell-free tubes had ST50 values of less than 4 days. In vertical Leighton tubes containing 6 ml of prereduced medium incubated aerobically, gradients of O2 tension and redox potential were established. Attachment and survival of T. pallidum were greatest at a depth of about 10 to 20 mm. Motility was between 70 and 95% in this area throughout the first 14 days of incubation. Occasionally, greater than 50% motility was observed for as long as 21 days. The redox potential and O2 tension in the optimal area of gradient cultures were reproduced by adjusting the medium depth in a shell vial culture system containing cells on a horizontal cover slip. Treponemes associated with the cell monolayer in both gradient and shell vial cultures were still virulent after 21 days in vitro. The dilution of testis extract and the concentration of T. pallidum were found to be important factors in survival of T. pallidum.
Extracellular neuraminidase production by group B streptococci
Authors: Milligan T W , Straus D C , Mattingly S J
Published: January 2020

Neuraminidase (sialidase) activity in concentrated culture filtrates of group B streptococci was measured with bovine submaxillary mucin as substrate. Group B streptococcal neuraminidase was not active on human alpha-1 acid glycoprotein and did not show increased activity on bovine submaxillary mucin that had been O-deacetylated by alkaline treatment. The enzyme was produced in a variety of media, including a chemically defined medium (FMC; Terleckyj et al., Infect. Immun. 11:649-655, 1975) supplemented with bovine serum albumin or human serum albumin. Maximal levels of activity were present in filtrates from cells grown in a dialyzable fraction of Todd-Hewitt broth harvested during the late exponential phase of growth. Dramatic decreases were seen when filtrates from the late stationary phase were assayed. The decrease in specific activity during the stationary phase was shown to be due to proteolytic digestion of neuraminidase and not to the elaboration of an extracellular neuraminic acid aldolase.
Role of host immune response in the development of either encephalitic or paralytic disease after experimental rabies infection in mice
Authors: Iwasaki Y , Gerhard W , Clark H F
Published: January 2020

The clinical and histopathological manifestations of the infection of immunosuppressed (cyclophosphamide-treated) and immunocompetent (control) adult mice with the CVS ts 2 strain of fixed rabies virus were correlated with the kinetics of virus multiplication in the central nervous system and with the development of serum antibody. In immunocompetent mice severe paralytic disease causing 80% mortality was accompanied by marked inflammation and degeneration of the central nervous system parenchymatous tissue. Antirabies antibody was detected in all immunocompetent mice severely paralyzed from postinoculation day 6 on; virus was rarely isolated. In contrast, immunosuppressed mice developed encephalitic symptoms with only minor paralysis; the infection was 100% fatal. Histopathological changes in immunosuppressed mice were confined to degeneration and necrosis of individual neurons and mild microglial reaction; virus was isolated from all of these mice. No significant level of antibody was detected. Similar manifestations were seen after infection of immunodeficient (athymic) mice except that the athymic mice developed levels of antibody similar to those of control mice on day 6; antibodies in athymic mice were predominantly of immunoglobulin class M.
Effect of some R factors on the sensitivity of rough Enterobacteriaceae to human serum
Authors: Fietta A , Romero E , Siccardi A G
Published: January 2020

Eight plasmids out of 26 tested confer partial serum resistance to Escherichia coli K-12 strains (Bhs character). Four Bhs+ plasmids were tested in a rough Salmonella typhimurium host, and three conferred partial serum resistance to this host as well. Plasmids representative of 19 different incompatibility groups were examined; the Bhs+ property was found in some (but not all) representatives of groups N, O, S, T, W, and F'lac (FI), and there was no apparent association between other plasmid markers and Bhs. It is likely that more than one mechanism can promote the Bhs+ phenotype and that Bhs genes are responsible for modifications of the surface structures involved in serum sensitivity.
Mycoplasma-dependent activation of normal lymphocytes: role of arginine and nonviable mycoplasma antigen in the induction of lymphocyte-mediated cytotoxicity for syngeneic mouse target cells
Authors: Aldridge K E , Cole B C , Ward J R
Published: January 2020

The ability of arginine supplementation to abrogate or potentiate Mycoplasma arthritidis-mediated cytotoxicity induction by normal CBA mouse lymphocytes was investigated. Also, nonviable antigens of M. arthritidis were assayed for their ability to induce a cytotoxic response. The presence of additional arginine in the culture medium had no significant effect on the amount of cytotoxicity produced. In some cases, an increase in cytotoxicity was seen in the presence of additional arginine. Amino acid analysis of the culture supernatants showed that the arginine in the nonsupplemented medium was exhausted during the assay, whereas ample amounts of arginine were present in the supplemented medium. However in both cases the amount of cytotoxicity was comparable. Nonviable antigens of M. arthritidis were unable to induce a significant cytotoxic response in the presence of normal lymphocytes. The same antigens exhibited a suppressive response when tested for blastogenesis in the presence of normal lymphocytes. A discussion of lymphocyte involvement is presented.