bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet aggregation in rabbits made tolerant to endotoxin
Authors: Walker R I , Shields L J , Fletcher J R
Published: January 2020

Endotoxin may cause abnormal deposition of platelet-endotoxin aggregates, and this event could have damaging effects. We compared the aggregation characteristics of platelets from rabbits made tolerant to the lethal effects of endotoxin with those of platelets from normal rabbits. Platelets from tolerant rabbits aggregated more rapidly (greater than 90 s faster) in the presence of endotoxin than did platelets from nontolerant animals. Furthermore, platelets from tolerant animals aggregated reversibly. These characteristics of platelets from tolerant animals are due to humoral factors in the plasma, because 1:1 dilution of normal platelet-rich plasma with plasma from tolerant rabbits caused the normal platelets to behave like those from tolerant animals. Survival after challenge with lethal quantities of endotoxin was enhanced in tolerant rabbits; this may be due to promotion of more efficient removal of endotoxin-platelet complexes from the blood by the reticuloendothelial system.
Influence of encapsulation on staphylococcal opsonization and phagocytosis by human polymorphonuclear leukocytes
Authors: Peterson P K , Wilkinson B J , Kim Y , Schmeling D , Quie P G
Published: January 2020

In previous studies, encapsulated Staphylococcus aureus strains have been shown to resist phagocytosis. In this investigation, the nature of the interference with phagocytosis by human polymorphonuclear leukocytes was examined by studying the opsonization of two pairs of unencapsulated (Smith compact and M variant) and encapsulated (Smith diffuse and M) S. aureus strains. The uptake of [3H]glycine-labeled bacteria by normal leukocytes was quantitatively measured after incubation of bacteria in pooled serum, C2-deficient serum, immunoglobulin-deficient serum, and serum from a rabbit immunized with S. aureus M. The presence of a capsule was found to interfere with opsonization by both the classical and alternative pathways of complement as well as by heat-stable opsonic factors in nonimmune human serum. This interference was significantly greater in the case of the S. aureus M strain than in the case of the Smith diffuse strain. The only effective opsonic source for S. aureus M was immune rabbit serum. It is proposed that encapsulation of S. aureus strains interferes with phagocytosis by preventing effective bacterial opsonization.
Tirandamycin: Inhibition of Ribonucleic Acid Polymerase
Authors: Reusser Fritz
Published: January 2020

Tirandamycin acts as a potent inhibitor of ribonucleic acid (RNA) polymerase in bacterial and mammalian cell-free test systems. The antibiotic inhibits the actively synthesizing template-enzyme-nascent RNA complex. Prolonged preincubation of RNA polymerase with tirandamycin prior to assay does not result in a drastic increase of tirandamycin inhibition. Tirandamycin inhibition is not reversed by further addition of deoxyribonucleic acid but is reversed upon further addition of RNA polymerase. Substantial inhibition of RNA polymerase is also obtained when the antibiotic is added at various times after initiation of the reaction. This suggests that tirandamycin interferes with the actively synthesizing template-RNA polymerase complex and inhibits chain elongation rather than chain initiation during RNA synthesis. Tirandamycin also interferes with oxidative phosphorylation in rat liver mitochondria and thus possesses two modes of action.
Phagocytosis and Bactericidal Activity of Leukocytes in Hemorrhagic Shock
Authors: Williams Armistead D. , Mandell Gerald L. , Lefer Allan M.
Published: January 2020

Polymorphonuclear leukocytes from dogs in hemorrhagic shock did not demonstrate impairment in phagocytosis or killing of
Staphylococcus aureus
or
Escherichia coli
in vitro.
Small-plaque variant of canine herpesvirus with reduced pathogenicity for newborn pups
Authors: Carmichael L E , Medic B L
Published: January 2020

The plaque characteristics of 13 field isolates of canine herpesvirus were found to be similar. After 312 passages of the F-205 strain in dog kidney cell cultures incubated at 35 degrees C, the virus still was virulent for newborn pups; it also had the macroplaque morphology of the wild-type virus. However, after 20 additional passages at 30 degrees C, a microplaque (mP) variant had emerged as the predominant type. Cloned mP virus retained the small-plaque characteristic after 66 transfers at 30 degrees C. The natural history of the mP strain and some of its biological properties are reported, the most significant being its lack of pathogenicity for newborn pups.
Filamentous Capsulated Streptococci from the Human Respiratory Tract: Chemical and Immunochemical Characterization of a Glycoprotein Capsular Antigen of Provisional Binary Capsular Type 87
Authors: Venkateswaran Pinayur S. , Stanton Nancy , Buettger Carol , Austrian Robert
Published: January 2020

A filamentous alpha-hemolytic streptococcus of provisional capsular type 87 isolated from the human respiratory tract has been shown to be binary capsulated. One of the capsular antigens appears to be a glycoprotein; the other appears to be a polysaccharide. Transformation reactions with deoxyribonucleic acid from streptococcus type 87 and a number of noncapsulated pneumococci yielded transformed pneumococci with either a glycoprotein capsule or a polysaccharide capsule, but not with both. Capsular precipitin (quellung) reactions were observed when streptococcus type 87 was treated with homologous antiserum or with antisera to either of the two distinct capsular transformants. Each of the transformed pneumococci gave a quellung reaction with its homologous antiserum or with antiserum to streptococcus type 87, but neither reacted with antiserum to the heterologous transformant. Chemical analysis showed the glycoprotein antigen of streptococcus type 87 to contain, in addition to amino acids, glucose, galactose, glucosamine, and phosphate. The amino acid composition of the glycoprotein capsular antigens from streptococcus type 87 and of those from transformed pneumococci were similar, showing only minor differences. The glycoprotein capsular antigen from streptococcus type 87 gave two closely associated precipitin bands with homologous antiserum or antisera to transformed pneumococci with the glycoprotein capsule. That the two precipitin bands represent two unrelated proteins is precluded largely on the basis of the unlikely probability of 100% cotransformation of the genes coding for both proteins in the pneumococcal transformants that were isolated. Chemical analyses of the various fractions of the glycoprotein indicate that the two precipitin bands may represent a glycoprotein and its corresponding apoprotein.
Substances that interfere with action of viridin B, a Streptococcus mitis bacteriocin
Authors: Dajani A S , Veres C M , Law D J
Published: January 2020

Several body fluids and various substances were examined for their effects on the action of viridin B, a Streptococcus mitis bacteriocin. Heme has been shown previously to interfere with viridin B action. In the present study, peroxidase and catalase, but not superoxide dismutase, interfered with the bacteriocin. Sulfhydryl-containing compounds had no effect. Trypsin, protease, and amylase exhibited interfering capacities. Of various body fluids tested, serum, saliva, and leukocyte lysate interfered with viridin B. The activity in leukocyte lysate was probably due to myeloperoxidase. Salivary activity was likely due to both peroxidase and amylase. Interfering activity in serum was neither complement dependent nor antibody mediated and was probably due to a combination of enzymatic activities. Temporal studies with these agents suggested more than one mechanism of interference with viridin B.
Heat-stable enterotoxin from Escherichia coli: factors involved in growth and toxin production
Authors: Johnson W M , Lior H , Johnson K G
Published: January 2020

Six enterotoxigenic strains of Escherichia coli produced variable levels of heat-stable enterotoxin (ST) when grown under pH control at 8.5 in a simple synthetic medium containing neither amino acids nor vitamins. Bacterial growth and ST production were at levels as high as or higher than those observed in complex media. ST elaboration was detectable in the early logarithmic phase of growth and appeared to be related to disappearance of glucose in the growth medium. The results of this study did not suggest pH-dependent release of ST. Imposition of pH control in complex media resulted in increased growth rates, earlier detectable ST synthesis, and elevated levels of ST. In synthetic medium, attainment of the stationary growth phase was followed by a significant decrease in culture density and a concomitant increase in ST. Cellular autolysis experiments revealed that as much as 20% of the total ST activity was present in a cell-associated form.
Cytopathogenicity of Mycoplasma hyopneumoniae in porcine tracheal ring and lung explant organ cultures alone and in combination with monolayer cultures of fetal lung fibroblasts
Authors: Williams P P , Gallagher J E
Published: January 2020

Porcine tracheal rings and lung explants alone and in combination with monolayer cultures of porcine lung fibroblasts (PLF) were separately inoculated with virulent strains of Mycoplasma hyopneumoniae and incubated at various times. The preparations were observed by bright-field, phase-contrast, and scanning electron microscopy. In PLF cultures, the strains at initial concentrations of 10(1.3) colony-forming units/ml increased within 3 days to 10(6) colony-forming units/ml, showed progressive clustering on the cells, and caused some sloughing. Introduction of a tracheal ring or lung explant into these mycoplasma-infected PLF cultures caused the explant to lose its epithelial ciliary motility. Eventually parts or whole cells of the respective ciliated epithelium were lost. Without infected PLF monolayers, the explants inoculated with M. hyopneumoniae were less susceptible to infection. When uninfected explants were incubated for 18 days or kept in stock for 2 months, they did not show the above changes. With 5 h postinoculation, M. hyopneumoniae cultures became intimately associated with the PLF culture, but when epithelial cell sloughing occurred, the mycoplasmal cells became dependent on the introduction of a fresh PLF monolayer or a tracheal or lung explant for survival.
Role of iron in disseminated gonococcal infections
Authors: Payne S M , Holmes K K , Finkelstein R A
Published: January 2020

Strains of Neisseria gonorrhoeae isolated from disseminated gonococcal infections have enhanced ability to acquire iron in an experimental host when compared with urogenital gonococcal isolates from patients with uncomplicated infections.
Enzyme-linked immunosorbent assay for measurement of serological response to respiratory syncytial virus infection
Authors: Richardson L S , Yolken R H , Belshe R B , Camargo E , Kim H W , Chanock R M
Published: January 2020

An enzyme-linked immunosorbent assay was applied to the detection of serum antibodies against respiratory syncytial virus. The end points of the various sera tested in the assay were approximately 100 times higher than in the complement-fixation test and 2 to 4 times higher than in the plaque reduction test. In addition, the immunosorbent assay appeared to be more efficient than the plaque reduction and complement-fixation techniques for detecting a serological response in young infants (1 to 6 months old) with serous respiratory syncytial virus lower respiratory disease. The simplicity, sensitivity, and rapidity of the enzyme-linked immunosorbent assay make it a useful tool for immunological studies with respiratory syncytial virus.
Stimulation of Subpopulations of Human Lymphocytes by a Vaccine Strain of
Francisella tularensis
Authors: Tärnvik Arne , Holm Stig E.
Published: January 2020

When purified T lymphocytes from individuals vaccinated with a viable, attenuated strain of
Francisella tularensis
were incubated in vitro in the presence of heat-killed bacteria or a membrane preparation of the vaccine strain, they were stimulated to form blast cells and to synthesize deoxyribonucleic acid. The blast cells had the characteristics of T cells, being devoid of surface immunoglobulin and able to form rosettes with sheep erythrocytes. The stimulation occurred only when monocytes were present. A lymphocyte preparation enriched in B lymphocytes did not respond to the heat-killed bacteria or to the membrane preparation. In a stimulated mononuclear leukocyte preparation, about 70% of the blast cells formed rosettes with sheep erythrocytes, and 10 to 20% of them had surface immunoglobulin. The results show that there is an enlarged population of specifically committed T lymphocytes after tularemia vaccination. It is suggested that the lymphocyte stimulation test measures mainly T-lymphocyte reactivity when membranes or whole bacteria of
F. tularensis
LVS are used as antigen, and that the stimulation of human T lymphocytes by whole bacteria or bacterial membranes is completely monocyte or macrophage dependent. The present experimental procedure may provide a model for study of antigen-induced stimulation of human lymphocytes under controlled conditions. The technique used gave a reproducible, extremely purified preparation of T lymphocytes and a preparation of monocytes especially suitable for microcultures.
Application of charge shift electrophoresis to antigenic analysis of mycoplasmic membranes by two-dimensional (crossed) immunoelectrophoresis
Authors: Alexander A G , Kenny G E
Published: January 2020

Both the anodic migration and resolution of membrane antigens of Mycoplasma arginini were greatly improved in two-dimensional immunoelectrophoresis by incorporating both a neutral detergent, Triton X-100, and an anionic detergent, sodium deoxycholate, in the agarose support for first phase electrophoresis. The mobility of cytoplasmic antigens was unaffected at concentrations of 0.1% or less of sodium deoxycholate.
Persistent shedding of adenovirus in urine of chimpanzees
Authors: Asher D M , Hooks J J , Amyx H L , Luber N P , Asher L V , Gibbs C J , Gajdusek D C
Published: January 2020

A new adenovirus, designated Pan 11, was isolated repeatedly from the urine of several chimpanzees for more than 1 year. One chimpanzee had chronic interstitial nephritis; the others were healthy. Most chimpanzees tested had neutralizing antibodies to Pan 11 virus in the serum; three people who worked with chimpanzees also acquired antibodies. Transplantable rhabdomyosarcomas developed in hamsters inoculated as newborns with Pan 11 virus.
Experimental production of respiratory tract disease in cebus monkeys after intratracheal or intranasal infection with influenza A/Victoria/3/75 or influenza A/New Jersey/76 virus
Authors: Grizzard M B , London W T , Sly D L , Murphy B R , James W D , Parnell W P , Chanock R M
Published: January 2020

A total of 28 cebus monkeys were inoculated intratracheally or intranasally with 10(6) 50% tissue culture infective doses of A/New Jersey/76 virus or 10(7) 50% tissue culture infective doses of A/Victoria/75 virus, and 8 additional monkeys received sterile allantoic fluid. Each of the animals became infected as evidenced by a serological response and/or shedding of the virus. Of the 10 animals inoculated intratracheally with A/Victoria/75 virus, 8 developed a systemic illness, and pulmonary infiltration was detected by X-ray in 7 of the 8. Administration of A/New Jersey/76 virus intratracheally to 10 monkeys produced a mild systemic illness in 2 animals and an upper respiratory tract illness in 6, but no illness developed in the remaining 2 monkeys; none of the animals developed X-ray evidence of lower respiratory tract disease. Intranasal administration of either virus failed to induce any illness or produced, at most, mild illness confined to the upper respiratory tract. These studies demonstrate that cebus monkeys are susceptible to respiratory tract infection with influenza A viruses and that the development of pulmonary disease is reflected in the appearance of easily recognizable radiological changes.
Local and systemic immunity to influenza infections in ferrets
Authors: Barber W H , Small P A
Published: January 2020

To establish whether immunity to influenza infection in the ferret is local or systemic, two sites of challenge were utilized: the nose and the anatomically isolated tracheal pouch. Infection of either site did not spread to the other site, and challenge of either site resulted in seroconversion by 13 days. Simultaneous challenge of both sites 21 days after the primary infection revealed that prior infection of the pouch prevented subsequent reinfection of the pouch, but not infection of the nose. Thus, systemic immunity did not prevent the initiation of nasal influenza infection in the ferret. However, the duration of virus shedding from the nose was reduced to half of that seen when ferrets were infected for the first time, showing that the prior pouch infection did lead to a more rapid recovery from the subsequent nasal infection. Passively administered anti-influenza antibody did not prevent or modify the nasal infection, but it did prevent the pouch infection. This is consistent with the observation that an initial infection of the nose prevented pouch infection upon challenge 21 days later. The prior nasal infection also prevented the subsequent nasal infection. These data suggest that immunity to acquisition of influenza infection in the ferret is a local phenomenon, whereas recovery from active infection is influenced by systemic immune mechanisms.
Ciliated respiratory epithelial monolayers: new model for Mycoplasma pneumoniae infection
Authors: Gabridge M G , Gunderson H , Schaeffer S L , Barden-Stahl Y D
Published: January 2020

Hamster respiratory epithelial cells were cultured in a monolayer format, and 20% of the cells were ciliated. Mycoplasma pneumoniae attached to the epithelial cells in a neuraminidase-specific fashion and induced ciliostasis and cytonecrosis.
Protective effect of vaccination against Mycoplasma pulmonis respiratory disease in rats
Authors: Cassell G H , Davis J K
Published: January 2020

Intravenous vaccination of rats with either viable or Formalin-inactivated Mycoplasma pulmonis reduced the incidence and severity of lower respiratory tract lesions after intranasal challenge with viable organisms. Intranasal vaccination with killed organisms reduced the severity of rhinitis, but did not affect lesions in any other region of the respiratory tract. The maximum protection against upper tract lesions (rhinitis, otitis, and laryngotracheitis) was provided by intravenous immunization with viable organisms. Dual vaccination (intraperitoneal plus intranasal) with killed organisms provided no significant protection in any segment of the tract. However, these ineffective vaccine regimens did not potentiate the lesions. These results conclusively demonstrate that vaccination of rats against mycoplasma respiratory disease is feasible and also suggest that systemic vaccination may provide greater protection for the lungs than intranasal vaccination, at least when equivalent antigen doses are used.
Pseudomonas ribosomal vaccines: preparation, properties, and immunogenicity
Authors: Lieberman M M
Published: January 2020

The preparation, properties, and immunogenicity of ribosomal vaccines from Pseudomonas aeruginosa are described. These preparations, containing protein and RNA, were tested for immunogenicity by active immunization of mice and subsequent challenge with homologous, live bacteria. The results demonstrated that vaccines prepared from a majority of serotypes used were immunogenic, i.e., afforded 60 to 100% mouse protection against a challenge inoculum containing 8 to 50 50% lethal doses. In some cases vaccine doses as low as 1 microgram of RNA provided 100% mouse protection. Molecular sieve chromatography of a highly immunogenic ribosomal preparation on Sepharose 4B demonstrated the presence of two molecular weight fractions: (i) peak A, an excluded peak (thus having a molecular weight of at least 2 times 10(7)), and (ii) peak B, considerably retarded, with an elution position corresponding to a molecular weight of about 2.2 X 10(6), approximating that of typical 70S ribosomes. Both peaks A and B were immunogenic; however, the immunogenicity of peak A was greater (i.e., a smaller immunizing dose was required) than that of peak B. Peak A was shown to contain components of lipopolysaccharide in addition to protein and RNA (which comprised 80% of the dry weight of peak A). On the other hand, peak B was shown to be free of lipopolysaccharide, and 100% of its dry weight consisted of protein and RNA.
Depression of contact sensitivity by enhancement of suppressor cell activity in Pseudomonas aeruginosa-injected mice
Authors: Colizzi V , Garzelli C , Campa M , Falcone G
Published: January 2020

Heat-killed Pseudomonas aeruginosa depresses contact sensitivity to oxazolone in C56BL/6 mice. The draining lymph nodes and spleens of mice exhibiting an impaired reactivity to oxazolone contain a cell population capable of depressing the response to oxazolone of recipients sensitized immediately before cell transfer. The suppressive activity of these cells appears to be antigen specific, since they do not affect the response to picryl chloride and because they do not arise in P. aeruginosa-injected but not oxazolone-sensitized mice. These suppressor cells occur in the draining lymph nodes and spleen at 3 and 4 days after sensitization, respectively, and have precursors sensitive to cyclophosphamide. It is concluded that P. aeruginosa depresses contact sensitivity to oxazolone by enhancing the suppressor cell activity of the regulatory cells which arise during conventional sensitization.
Suppression and enhancement of mitogen response in chickens infected with Marek's disease virus and the herpesvirus of turkeys
Authors: Lee L F , Sharma J M , Nazerian K , Witter R L
Published: January 2020

The kinetics of phytohemagglutinin (PHA) response of peripheral blood lymphocytes from chickens infected with oncogenic Marek's disease (MD) virus (MDV) or nononcogenic herpesvirus of turkeys (HVT) was studied with a whole blood microassay. At about 7 days after inoculation, a depression in PHA response was observed in MDV-inoculated resistant line N or susceptible line 7(2) chickens and in HVT-inoculated line 7(2) chickens. All chickens initially regained their PHA responsiveness. Susceptible chickens that died of MD or developed MD lymphoma in later stages of virus infection showed a second severe depression in PHA response. No depression was observed in HVT-vaccinated chickens when challenged with MDV. The PHA response of MDV-inoculated chickens that survived MD, HVT-inoculated chickens, and HVT-vaccinated MDV-challenged chickens showed evidence of enhancement. The depression of PHA response was studied and was attributed to the suppressive effect of macrophages on T-cell response, a finding consistent with our previous studies on MDV suppression of PHA response.
Studies on gonococcus infection. XV. Identification of surface proteins of Neisseria gonorrhoeae correlated with leukocyte association
Authors: King G J , Swanson J
Published: January 2020

Neisseria gonorrhoeae which exhibit high levels of leukocyte association have a surface protein which is considerably diminished in isogenic gonococci which exhibit low levels of leukocyte association (LA). The LA protein exhibits strain variation in molecular weight and immunogenicity. Membranes derived from LA+ and LA- organisms show quantitative differences in their adsorption to leukocytes; these differences are analogous to those found for the intact organisms regarding their association with leukocytes.
Disruption of the permeability barrier (zonula occludens) between intestinal epithelial cells by lethal doses of endotoxin
Authors: Walker R I , Porvaznik M J
Published: January 2020

A freeze-fracture technique was used to examine the most apical intercellular junctional complex between intestinal epithelial cells (the tight or occluding junction) in mice after challenge with endotoxin. Some of these junctions were disrupted after challenge and may be a site for leakage of microbial agents from the lumen.
Cerebrospinal fluid and serum immunoglobulins and antibody titers in mumps meningitis and aseptic meningitis of other etiology
Authors: Fryden A , Link H , Norrby E
Published: January 2020

Cerebrospinal fluid (CSF) and serum from 19 patients with mumps meningitis and 19 patients with meningitis of other etiology were investigated on two or more occasions for at least 1 month after onset. Intrathecal synthesis of immunoglobulin (Ig) G was found in 55%, of IgA in 26%, and of IgM in 24% of the patients. Oligoclonal Ig was demonstrable by agarose gel electrophoresis in 37% of the patients, mostly already during the first week after onset, and could persist for years. Mumps virus antibody synthesis within the central nervous system occurred in 37% of the mumps meningitis patients. The inflammatory reaction within the central nervous system as reflected by mononuclear pleocytosis, Ig synthesis, and oligoclonal Ig was not correlated to the clinical course. The blood-brain barrier was evaluated by determination of the CSF total protein, CSF/serum albumin ratio, and CSF/serum alpha2-macroglobulin ratio. A significant correlation was found among these three parameters. Persistence of the elevated CSF/serum albumin ratio seems to influence prognosis, and this parameter is recommended for evaluation of the blood-brain barrier function.
Mechanism of coaggregation between Actinomyces viscosus T14V and Streptococcus sanguis 34
Authors: McIntire F C , Vatter A E , Baros J , Arnold J
Published: January 2020

Actinomyces viscosus T14V and Streptococcus sanguis 34 coaggregate by a mechanism which is not inhibited by 1 M NaCl, is dextran independent, requires calcium, is pH dependent with an optimum at pH 8.0 to 8.5, and appears to require the interaction of a protein or glycoprotein on A. viscosus with a carbohydrate on S. sanguis. The coaggregation is inhibited more than 80% by 0.01 M lactose, 0.02 M beta-methyl-D-galactoside, or 0.05 M D-galactose; inhibition of coaggregation was less than 10% in 0.1 M alpha-methyl-D-galactoside, melibiose, maltose, cellobiose, sucrose, and a number of monosaccharides. At very high concentrations of enzyme, protease from S. griseus destroyed the reactive site on A. viscosus but not on S. sanguis. Both were totally resistant to dextranase. Periodate (0.01 M; pH 4) inactivated both bacteria. The ability of S. sanguis to coaggregate with A. viscosus was not destroyed by phenol-water extraction at 65 degrees C for 15 min. When the bacteria were cultured under specified conditions, the coaggregation was highly reproducible. Under the same conditions, T14AV, the avirulent mutant of A. viscosus T14V, did not coaggregate with S. sanguis 34. Electron microscopic studies of coaggregates, labeled immunochemically with antibody to A. viscosus, indicated that fibrils on A. viscosus may be involved in the coaggregation.
Regional T- and B-cell responses in influenza-infected ferrets
Authors: McLaren C , Butchko G M
Published: January 2020

Ferrets were infected with A/Port Chalmers/72 influenza virus and the T- and B-cell responses in the spleen, in lymph nodes draining the upper and lower respiratory tract, and in lung washings were examined in vitro. Lymphocyte responses were measured by using a hemolytic plaque assay for B cells and a proliferation assay for T cells. Virus and antibody levels were measured in respiratory tract washings, and antibody titers were measured in sera from infected animals. Individual B cells secreting specific antibody to A/Port Chalmers/72 virus were detected in regional lymph node and spleen preparations as early as 3 days and as late as 43 days after infection. T-cell assays showed an in vitro response of lymph node cells to A/Port Chalmers/73 virus from day 6 to day 43. Virus was isolated from the respiratory tract up to 7 days after infection. Serum hemagglutination-inhibiting antibody was first detectable on day 6, with maximum titers reached by day 10. These results demonstrated that antibody production and a cellular immune responses were detectable at regional sites at a time when virus was still present and before serum antibody was measured.
Effect of
Escherichia coli
Heat-Stable Enterotoxin on Cyclic GMP Levels in Mouse Intestine
Authors: Newsome P.M. , Burgess M.N. , Mullan N.A.
Published: January 2020

Partially purified heat-stable enterotoxin obtained from
Escherichia coli
strain F11/P155 caused an accumulation of cyclic GMP in the intestines of 8-day-old mice.
Effects of temperature on the stability of Rickettsia tsutsugamushi and gamma-irradiated scrub typhus immunogens
Authors: Eisenberg G H , Osterman J V
Published: January 2020

Unirradiated Rickettsia tsutsugamushi and a component of gamma-irradiated Karp immunogen required for homologous immunity were more stable than the immunogen component that elicited heterologous (Kato strain) protection.
Increased resistance to streptolysin O in mammalian cells treated with oxygenated derivatives of cholesterol
Authors: Duncan J L , Buckingham L
Published: January 2020

L-cell fibroblast cultures were treated with certain oxygenated derivatives of cholesterol which are known to inhibit cholesterol biosynthesis in mammalian cells. After incubation in the presence of 20-alpha-hydroxycholesterol or 25-hydroxycholesterol for 18 h, the cells became increasingly resistant to streptolysin O. Maximum resistance to toxin was obtained by incubation for 48 h in 0.5 microgram of 20-alpha-hydroxycholesterol or 0.25 microgram of 25-hydroxycholesterol per ml; under these conditions, the cells were 10 to 50 times more resistant than were untreated controls. The ability of the hydroxycholesterol compounds to render the cells resistant was related to the age of the cultures. Maximum protection was found when more sparsely populated cultures were treated with 25-hydroxycholesterol. Older, heavily populated cultures could not be protected even with the high concentrations of 25-hydroxycholesterol. In contrast to control cultures, most of the toxin activity remained in the medium after being incubated with hydroxycholesterol-treated cultures. The results indicate that less toxin binds to the resistant cells and suggest that a reduction in membrane cholesterol content may account for resistance to streptolysin O.
Alterations in the tRNA's of Escherichia coli recovered from lethally infected animals
Authors: Griffiths E , Humphreys J , Leach A , Scanlon L
Published: January 2020

Escherichia coli grown in chemically defined iron-deficient media or in fluids containing the iron-binding proteins transferrin, lactoferrin, or ovotransferrin have well-characterized alterations in the chromatographic properties of tRNA's containing the modified nucleoside 2-methylthio-N6-(delta2-isopentenyl)-adenosine. The present work shows that similar tRNA alterations occur in E. coli O111 recovered from the peritoneal cavities of lethally infected guinea pigs and rabbits. Adding iron to these in vivo-grown bacteria resulted in the rapid conversion of chromatographically abnormal tRNA's to the normal species. The work strongly suggests that host iron-binding proteins, present in mucosal and other secretions, can affect the metabolism of invading organisms. The idea that the tRNA alterations are connected with the adaptation of E. coli to growth under the iron restricted conditions imposed by iron-binding proteins in tissue fluids, and thus with bacterial pathogenicity, is therefore made particularly attractive.
Suppression of cellular immune responses in guinea pigs infected with spotted fever group rickettsiae
Authors: Oster C N , Kenyon R H , Pedersen C E
Published: January 2020

Using a guinea pig model, we demonstrated that infections with pathogenic species of spotted fever group rickettsiae transiently and nonspecifically suppress established cellular immune responses as measured by in vitro lymphocyte transformation and in vivo delayed cutaneous hypersensitivity responses to unrelated, nonrickettsial antigens. The correlation of the duration of this immunosuppression with the virulence of the infecting rickettsial species suggests that this suppression is a pathological effect of the rickettsial infection. Although we did not specifically study the mechanism of this suppression, it is not associated with either lymphocytopenia or leukocytosis.
Growth of Mycobacterium lepraemurium in nonstimulated and stimulated mouse peritoneal-derived and bone marrrow-derived macrophages in vitro
Authors: Alexander J , Smith C C
Published: January 2020

Mycobacterium lepraemurium cells were found to multiply in normal mouse peritoneal-derived and bone marrow-derived macrophages in vitro. Whereas activated peritoneal-derived macrophages demonstrated marked bacteriostasis for M. lepraemurium, significant bactericidal activity was exhibited by activated bone marrow-derived macrophages. However, only a small proportion of the bacterial were killed by activated bone marrow-derived macrophages with subsequent and enhanced bacteria growth. It is suggested that a rapid turnover of monocytes in active lesions is required to control mycobacterial infections in vivo. These results would suggest that careful consideration be given to the choice of the host cell in studies involving obligate intracellular parasites.
Heat-labile B-cell mitogen obtained from Listeria monocytogenes
Authors: Kearns R J , Hinrichs D J
Published: January 2020

A water-soluble extract of Listeria monocytogenes strain 10403 acts as a mitogen on cultured mouse spleen lymphocytes. This mitogen induced a response six to nine times that of controls, as measured by [3H]thymidine incorporation. The mitogen extract was derived from washed bacterial cells which were mechanically disrupted with a French press. The extract was centrifuged at 105,000 X g and filtered through a 0.22-micrometer filter. Similar levels of lymphocyte stimulation were observed in lymphocyte cultures prepared from spleens of nude mice, indicating the effect of this mitogen on B-cells. The mitogenic property of this extract was destroyed by heating to 56 degrees C. This heat treatment does not destroy the antigens in the extract, which stimulate spleen cell cultures obtained from specifically immune mice. Similarly prepared extracts from Staphylococcus epidermidis and Salmonella typhimurium did not show similar levels of mitogenic activity. The mitogenic property of the L. monocytogenes extract was present in two strains of Listeria tested and was not associated with mouse virulence.
Binding of cholesterol by Neisseria gonorrhoeae
Authors: Miller R D , Warren W J , Sizemore R C , Morse S A
Published: January 2020

The binding of [1,2-3H]cholesterol to Neisseria gonorrhoeae CS-7, Pseudomonas aeruginosa, and Salmonella typhimurium (smooth and rough strains) was investigated. The kinetics of cholesterol binding to N. gonorrhoeae CS-7 demonstrated that binding occurred slowly with maximum binding by 10 h. Under optimum conditions, a large percentage (65%) of the added cholesterol was associated with the cells. Chemical fractionation revealed that ca. 98% of the labeled cholesterol was associated with the cell membrane(s). The bound cholesterol was not esterified and was associated primarily with the cytoplasmic membrane. Intact gonococci bound 4 to 30 times more cholesterol than the deep rough mutant S. typhimurium TA1535, the wild-type S. typhimurium DB-21, and P. aeruginosa. In contrast, isolated cell membranes from all organisms rapidly bound cholesterol to the same extent. Therefore, the outer membrane can function as a permeability barrier to cholesterol. Cholesterol binding to both whole cells and isolated cell membranes was influenced by the incubation temperature. The rate of cholesterol binding by whole cells of N. gonorrhoeae decreased markedly at lower temperatures, with almost complete cessation of binding at 0 degrees C. A similar temperature effect on the binding of cholesterol to isolated membranes was not observed. Thus, the effect of temperature on the binding of cholesterol to whole cells was an effect not on the actual binding process but rather on the ability of the cholesterol molecule to penetrate the lipid domain of the gonococcal outer membrane.
Streptococcus mutans dextransucrase: stimulation by phospholipids from human sera and oral fluids
Authors: Schachtele C F , Harlander S K , Bracke J W , Ostrum L C , Maltais J A , Billings R J
Published: January 2020

Serum, gingival crevicular fluid, and parotid, submandibular, and labial minor gland saliva from four individuals stimulated glucan formation from sucrose by the Streptococcus mutans strain 6715 dextransucrase (EC 2.4.1.5). At final dilutions of 1:10 all of the fluids stimulated crude enzyme preparations approximately 1.8-fold. The fluids stimulated the purified water-insoluble glucan-synthesizing form of the dextransucrase approximately 3.2-fold and the water-soluble glucan-producing form of the enzyme approximately 2.4-fold. The fluids all contained concentrations of stimulatory material that could be reduced to undetectable levels only after dilutions of greater than 1:1,000. The increased rates of glucan formation caused by the fluids and dextran were additive, indicating that stimulation by the fluids was primarily due to interactions with entities other than glucan primer molecules. In contrast, the elevated levels of glucan formation in the presence of the fluids was not further enhanced by the addition of lysophosphatidylcholine. Lysophosphatidylcholine purified from parotid and submandibular saliva by solvent extraction and thin-layer chromatography stimulated the dextransucrase as effectively as egg yolk lysophosphatidylcholine. Thus, phospholipids normally found in human oral fluids can enhance the activity of an enzyme believed to be directly associated with the cariogenic potential of S. mutans.
Phytohemagglutinin stimulation of enhanced immunoglobulin G production in mice inoculated with type III pneumococcal polysaccharide
Authors: Vogel S N , Roberson B S
Published: January 2020

In BALB/c mice previously inoculated intraperitoneally with an immunogenic dose of the T-independent antigen type III pneumococcal polysaccharide, the intravenous administration of the T-cell activating agent phytohemagglutinin P causes a pronounced increase in the number and relative proportion of immunoglobulin G-producing cells. These results, detected by a modified hemolytic plaque assay, were supported by finding increased levels of serum immunoglobulin G anti-type III pneumococcal polysaccharide in the treated mice. A comparable stimulation of immunoglobulin G antibody-producing cells was not induced in phytohemagglutinin P-treated nude mice, indicating that the change in class of the predominant antibody is attributable to the activation by the phytohemagglutinin P of a T-cell population. Under the conditions of these experiments, phytohemagglutinin P also promotes a progressive suppression of the antibody-forming cells during the response to type III pneumococcal polysaccharide.
Significance of an in vitro phenomenon in which murine erythrocytes are lysed by autologous spleen cells and spherules of Coccidioides immitis
Authors: Danley D L , Hilger A E , Boonlayangoor P , Millhouse E W
Published: January 2020

Spleen cells from mice immunized with a variety of antigens and incubated in vitro with killed spherules of Coccidioides immitis lyse six to eight times more autologous murine erythrocytes than normal spleen cells and spherules. Cellular and biochemical events in this phenomenon were investigated to ascertain its significance. Kinetic studies suggested that hemolysis results from the activation of some immune cells by spherules. The capacity of spherules to activate these cells is rather unusual because, of the inert particles tested, only zymosan A and crude chitin demonstrated comparable activity. Furthermore, although the hemolytic phenomenon occurred in serum-free medium, more lysis was effected by immune cells and opsonized spherules or zymosan A than by immune cells and untreated fungal particles. Sheep, chicken, and human erythrocytes were not lysed in the hemolytic phenomenon; however, hemoglobin in chicken and sheep erythrocytes was oxidized. Both the murine erythrocyte lysis and oxidation of ovine hemoglobin correlated with the reduction of Nitro Blue Tetrazolium by immune cells adherent to spherules, and both phenomena appeared to be mediated by H2O2 released into the medium by activated cells. Spleen cells reactive with spherules could not be depleted by treatment with iron carbonyl, antiimmunoglobulin plus complement, or anti-brain-associated theta plus complement, but they were partially or completely depleted after rosette formation with erythrocytes coated with antibody or murine complement. Using light and electron microscopy, we noted that immune spleens contained more neutrophils than normal spleens, that these neutrophils reduced Nitro Blue Tetrazolium after stimulation with phorbol myristate acetate, and that they were the most prevalent cell type adherent to spherules after incubation in vitro.
Adhesion of commensal bacteria to the large intestine wall in humans
Authors: Hartley C L , Neumann C S , Richmond M H
Published: January 2020

Biopsies taken during colonoscopic examination of the human large bowel were used to examine the relationship of the commensal bacterial to the mucosal epithelial cell surface. Bacteria were seen adhering to the exposed epithelial cell surface and also to the mucus sheet. Isolation of aerobic organisms showed that Escherichia coli are closely associated with the gut wall throughout the large intestine. One strain of E. coli predominated in each biopsy, and this strain was present along the whole length of bowel. Adhesion of bacteria to the gut wall does occur in vivo and may be one of the factors involved in the ability of an organism to colonize and persist.
Splenomegaly in murine trypanosomiasis: T cell-dependent phenomenon
Authors: Robinett J P , Rank R G
Published: January 2020

Splenomegaly resulting from Trypanosoma musculi infection was found to be dependent upon a functioning T-lymphocyte system. When both humoral and cell-mediated immune systems were suppressed by treatment with cyclophosphamide 2 days after infection, splenomegaly was inhibited for about 6 days. However, when only humoral immunity was suppressed by treatment with cyclophosphamide 3 days before infection, splenomegaly still occurred. In addition, splenomegaly was absent in congenitally athymic nude mice. Nude mice and immunologically intact heterozygote mice were also sacrificed at varying times after infection, and spleens were examined histologically. A lymphocytic hyperplasia was observed in immunologically intact mice but not in nude mice. These data indicate that splenomegaly of T. musculi infections is T cell dependent and that splenomegaly is the result of a proliferation of B and/or T lymphocytes.
Cell-free and cell-bound antibody in nasal secretions from infants with respiratory syncytial virus infection
Authors: McIntosh K , McQuillin J , Gardner P S
Published: January 2020

Twenty-two infants under 9 months of age hospitalized with bronchiolitis or pneumonia due to respiratory syncytial virus (RSV) were serially sampled to determine the pattern of secretory antibody response. Using double labeling techniques, we found several types of immunoglobulin in secretions: cell-free antibody to RSV of the immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) classes; and immunoglobulins of all three classes bound to RSV-infected cells shed from the nasal epithelium (presumably cell-bound antibody to RSV). IgA attached to RSV-infected epithelial cells was almost always detected in the first available nasal sample (day 1 or 2 of hospitalization). In contrast, cell-free anti-RSV IgA first appeared an average of 3.5 days later at a time when virus antigen was disappearing from the secretion. IgG and IgM attached to RSV-infected cells appeared more irregularly. The titer of cell-free anti-RSV IgM was often higher than that of IgA early in the illness and declined as the infection resolved. Cell-free anti-RSV IgG was usually present earlier than IgA and rose during convalescence.
Assessment of Coxsackievirus B3
ts
Mutants for Induction of Myocarditis in a Murine Model
Authors: Trousdale Melvin D. , Paque Ronald E. , Nealon Timothy , Gauntt Charles J.
Published: January 2020

Ten temperature-sensitive (
ts
) mutants isolated from a myocarditis-inducing wild-type (WT) coxsackievirus B3 parent did not induce myocarditis in adolescent CD-1 mice. An avirulent prototype
ts
mutant from one of the three complementation groups adsorbed to murine cardiac tissue, as did WT virus. Heart tissues from mice inoculated with WT virus contained 100- to 1,000-fold more virus than heart tissues from mice inoculated with any of the three prototype
ts
mutants. WT virus exhibited a greater capsid stability and a higher efficiency of replication at 37°C than any of the three prototype
ts
mutants. All three prototype
ts
mutants induced less interferon in vivo than WT virus. Cell-mediated immune responses, assessed by the cell migration inhibition assay, were different in mice inoculated with WT virus when compared to
ts
5 mutant virus. Peritoneal exudate cells from mice inoculated with WT but not
ts
5 virus reacted specifically against antigens in WT virus HeLa cell lysates and antigens extracted with KCl from cardiac tissues of mice inoculated with WT virus. Cardiac tissues of mice inoculated with WT but not
ts
5 virus contained KCl-extractable antigens which were able to specifically inhibit the migration of peritoneal exudate cells taken from mice immunized with WT virus. Therefore,
ts
5 neither elicited a measurable cell-mediated immune response nor induced antigens in cardiac tissues which were immunoreactive with sensitized-(WT virus)-peritoneal exudate cells. Of 9 revertant viruses isolated from the 10
ts
mutants, 5 showed covariance in ability to replicate at 39.5°C and capacity for induction of myocarditis. Some revertants exhibited a reduced capsid thermostability compared to WT virus but yet retained the capacity for induction of myocarditis. The data suggest that induction of myocarditis by coxsackievirus B3 variants depends on a combination of several variables, including capsid stability, capacity for replication at 37°C, and expression of the three identified genes. All three prototype
ts
mutants served as vaccine viruses in preventing myocarditis in adolescent mice subsequently challenged with WT virus. However, all three prototype
ts
mutants and their revertant variants retained partial to complete lethality in CD-1 neonates.