bluuebunny/crossref_metadata_2025 huggingface dataset:
Guanine-plus-cytosine composition of five group B streptococcal serotypes
Authors: Forbes B A , Ferretti J J
Published: January 2020

The percent guanine-plus-cytosine content of deoxyribonucleic acid of each of the five serotypes of group B streptococci was determined by thermal denaturation. The range of guanine-plus-cytosine content was 35.1 to 36.9%, with a mean value of 35.9%. These values suggest a genetic homogeneity to the serotypes of the group B streptococci.
Production of Extracellular and Cell-Associated Glucosyltransferase Activity by
Streptococcus mutans
During Growth on Various Carbon Sources
Authors: Janda William M. , Kuramitsu Howard K.
Published: January 2020

The production of extracellular and cell-associated glucosyltransferase activity by
Streptococcus mutans
strain GS-5 was examined during growth on various carbon sources in a chemically defined medium.
S. mutans
cells produced glucosyltransferase activity only during logarithmic growth when glucose, fructose, mannitol, or sorbitol was the sole carbon source. Cells growing on mannitol or sorbitol produced approximately half as much extracellular glucosyltransferase activity as cells growing on glucose, although the proportions of the glucosyltransferase activity capable of synthesizing insoluble glucans were similar. Cells growing on fructose produced slightly more extracellular glucosyltransferase activity than cells grown on glucose, yet the proportion of the glucosyltransferase activity capable of synthesizing insoluble glucans was again similar to glucose cultures.
S. mutans
cells growing in the presence of both glucose and mannitol displayed diauxic growth and initial preferential utilization of glucose. Glucosyltransferase enzyme production occurred only during the phases of cell growth in the presence of the two carbon sources. The cell-associated glucosyltransferase activities of glucose-, fructose-, mannitol-, and sorbitol-grown cells were relatively low, yet all the cells were capable of adherence to glass in the presence of sucrose. When glucose-containing cultures of
S. mutans
were supplemented with sucrose, extracellular glucosyltransferase activity first became cell associated and then appeared to become inactivated, presumably due to the accumulation of insoluble glucans.
Morphological features and functional properties of human fibroblasts exposed to Actinomyces viscosus substances
Authors: Engel D , Schroeder H E , Page R C
Published: January 2020

Connective tissue fibroblasts undergo cytopathic degenerative changes during certain long-term inflammatory diseases such as rheumatoid arthritis and periodontitis. The failure of inflamed tissues to repair properly may result from functional alterations of fibroblasts within the affected tissues. Numerous previous studies indicate that direct cytotoxicity by bacterial or other substances may be responsible for the cellular alterations observed in vivo. We have tested this hypothesis by exposing cultures of human diploid fibroblasts to homogenates of Actinomyces viscosus (a microorganism associated with periodontitis and capable of causing other chronic inflammatory diseases) and analyzing the effects on cell viability, morphology, and function. The cells bind and subsequently engulf relatively large quantities of the bacterial substances. These substances do not appear to be toxic to fibroblasts as determined by 51Cr release and microcytotoxicity assays, although there is a slight but significant decrease in protein synthesis (P less than 0.01) as measured by the incorporation of [14C]proline. However, collagen production was not altered, and the cytopathic alterations observed in diseased tissues in vivo did not occur in the exposed cells. These findings suggest that A. viscosus substances do not directly cause injury to connective tissue fibroblasts in periodontal disease but may, through cell-surface binding, mark these cells for subsequent immune-mediated damage.
Role of Staphylococcus aureus cell wall antigens in the stimulation of delayed hypersensitivity after staphylococcal infection
Authors: Easmon C S , Glynn A A
Published: January 2020

In Staphylococcus aureus-infected mice, prior treatment with cyclophosphamide enhanced delayed hypersensitivity to cell walls and peptidoglycan. S. aureus did not cross react with S. epidermidis or S. saprophyticus.
Reactivation of latent herpes simplex virus infection of the autonomic nervous system by postganglionic neurectomy
Authors: Price R W , Schmitz J
Published: January 2020

Latent herpes simplex virus infection of the superior cervical autonomic ganglion was reactivated in vivo by postganglionic neurectomy. Two methods were used to demonstrate viral reactivation: (i) recovery of infectious herpes simplex virus in ganglion homogenates and (ii) acceleration of virus expression in ganglion explants in culture. Both the percentage of mice exhibiting reactivated ganglion infection and the viral titers detected in ganglia increased when neurectomized mice were treated with cyclophosphamide. Antithymocyte serum treatment prolonged the time course over which neurectomy-induced virus could be detected, but neither antithymocyte serum nor cyclophosphamide reactivated herpes simplex virus in the absence of neurectomy. These results demonstrate that postganlionic neurectomy provides a specific stimulus for herpes simplex virus reactivation and that cell-mediated immune defense are involved in the highly efficient elimination of reactivated virus from the ganglion in vivo.
Impaired chemotactic responsiveness of macrophages from gnotobiotic rats
Authors: Jungi T W , McGregor D D
Published: January 2020

Peptone-induced macrophages obtained from gnotobiotic (GB) rats responded poorly to chemotactic stimuli that have a powerful, attractive influence upon the cells of conventional donors. Monocyte recruitment from the circulation into peptone-induced exudates also was impaired in GB subjects. Although relatively more resident cells are present in exudates borne by GB donors, their number cannot in itself account for the sluggish response of peptone-induced cells from GB rats. Neutrophil accumulation in the inflamed peritoneal cavities and their responsiveness in vitro were similar in GB and conventional rats. The levels of serum-derived chemotactic factors were similar in such animals. Furthermore, germ-free rats exhibited no obvious defects in their capacity to generate lymphocyte-dependent monocyte chemotactic activity in situ upon specific stimulation with Listeria monocytogenes. It is suggested that the diminished chemotactic responsiveness of exudate macrophages is related in some way to the level of cell activation. This state of affairs might account for the impairment of delayed-type hypersensitivity in GB animals and their inability to resist intracellular bacterial infections.
Electron Microscopic Study on Phagocytosis of Staphylococci by Mouse Peritoneal Macrophages
Authors: Iwata Kazuo , Kanda Yayoi , Yamaguchi Hideyo
Published: January 2020

Macrophages from the mouse peritoneal cavity were examined by electron microscopy at various time intervals up to 24 h after intraperitoneal administration of each of three strains of staphylococci different in virulence for mice: high-virulent, low-virulent, and avirulent strains. After engulfment, avirulent bacteria were highly liable to intracellular digestion, resulting in almost complete degradation within 24 h after injection, whereas high-virulent bacteria were more resistant to digestion, some showing figures suggestive of a dividing process; the gross configuration of most of the ingested bacteria was relatively well preserved over the 24-h period. Time-dependent morphological changes of low-virulent bacteria were intermediate. Among the most distinct cytoplasmic responses to the ingested bacteria was the formation of phagocytic vacuoles around them, the type of which was dependent on the staphylococcal strain infected; ingestion of avirulent bacteria led to formation of vacuoles in which the bacteria were surrounded by a halo of amorphous material of moderate density, which may be the lysosomal content. In contrast, larger vacuoles developed after ingestion of high-virulent bacteria and contained only a small quantity of such amorphous materials. Both types of phagocytic vacuoles were seen around the low-virulent bacteria ingested. Some degenerative changes were found in the macrophages ingesting high- or low-virulent bacteria, but were not in those ingesting avirulent bacteria. Thus, resistance to intracellular degradation, as well as cytotoxicity toward phagocytes of staphylococcal strains, can be correlated with their virulence.
Aging in vitro and large-scale interferon production by 15 new strains of human diploid fibroblasts
Authors: Horoszewicz J S , Leong S S , Ito M , Di Berardino L , Carter W A
Published: January 2020

To develop resources for large-scale production of human fibroblast interferon, we isolated, cryopreserved, and characterized 15 new strains of human diploid foreskin fibroblasts. Their life spans in vitro ranged from 52 to 72 population doublings. We based the selection of cell strains for mass interferon production on the number of population doublings during which consistently high yields of interferon were obtained after "superinduction" in roller bottles; our data show that aging in vitro leads to significant decline in amounts of interferon produced. In contrast, susceptibility to interferon remains largely unaffected by in vitro senescence. Karyotypic analysis indicated that the best interferon-producing strain, MLD (over 60,000 reference units/ml), has a translocation between chromosomes 5 and 15.
Potentiation of Endotoxicity by Carrageenan
Authors: Becker Larry J. , Rudbach Jon A.
Published: January 2020

Carrageenan can potentiate the lethal effects of endotoxin by 100- to more than 3,000-fold.
Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis
Authors: Lamont H C , Semine D Z , Leveille C , Nichols R L
Published: January 2020

Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.
Comparative Estimates of Bacterial Affinities and Adsorption Sites on Hydroxyapatite Surfaces
Authors: Clark W. B. , Bammann L. L. , Gibbons R. J.
Published: January 2020

The adsorption of strains of prominent oral bacteria to hydroxyapatite (HA) surfaces was studied by use of an adsorption model based on the Langmuir adsorption isotherm; this permitted comparative estimates of the number of adsorption sites and the strength of the adsorption bonds on untreated and salivatreated HA surfaces for strain of
Streptococcus mutans, S. salivarius, S. sanguis, S. mitis, Actinomyces viscosus
, and
A. naeslundii
. The experimental data closely followed the adsorption model as judged by the high correlation coefficients obtained for all strains studied. Adsorption to untreated HA was similar for strains of the six species studied, suggesting that a common adsorption mechanism, possibly Ca
2+
bridging, may exist for attachment to HA. More complex interactions appeared to be involved in bacterial adsorption to saliva-treated HA since adsorption of the strains tested at unsaturating cell concentrations varied more than 30-fold. This indicates that adsorbed salivary components on HA surfaces impart a higher order of specificity for subsequent bacterial adsorption. Fewer cells of strains of
S. mutans, S. salivarius
, and
A. naeslundii
adsorbed to saliva-treated HA than to untreated HA because adsorbed salivary components presented fewer adsorption sites. Substantially higher numbers of cells of strains of
S. sanguis, S. mitis
, and
A. viscosus
adsorbed to saliva-treated HA because the film of adsorbed salivary components increased the number of adsorption sites for these strains. The affinity constants for all but one strain studied were lower on saliva-treated HA than on untreated HA. The number of bacterial cells which adsorbed to saliva-treated HA more closely related to the number of available binding sites than to the strength of their adsorption bonds when tested at an initial concentration of 2 × 10
7
organisms/ml. Although some differences were observed in the adsorption of strains of
S. mutans
representative of five serological groups, the numbers which attached to saliva-treated HA did not vary widely; this suggests that factors other than their ability to attach to a pellicle-covered HA surface may be responsible for their varying geographic distribution in human populations.
Lymphocyte blastogenic responses to influenza virus antigens after influenza infection and vaccination in humans
Authors: Dolin R , Murphy B R , Caplan E A
Published: January 2020

Virus-specific in vitro cell-mediated immune responses were investigated in 20 normal volunteers who were challenged with liver influenza A/VIC/3/75 (H3N2) virus and in 13 volunteers who were vaccinated with inactivated vaccine containing A/VIC and A/NJ/8/76 (HswN1) antigens. Lymphocyte cultures were established from peripheral blood samples obtained prior to and at various times after infection or vaccination. Blastogenesis was determined by [3H]thymidine incorporation after stimulation of cultures with purified, inactivated, whole influenza viruses. Six days after infection, significantly elevated levels of blastogenesis were observed after in vitro stimulation with A viruses of hemagglutinin and neuraminidase subtypes that were the same as (H3N2) or antigenically distinct from (Heq1Neq1 or HswN1) those of the challenge virus, although maximum stimulation was noted with virus of the same hemagglutinin subtype (H3) as the challenge virus. Similar although more prolonged blastogenic responses were noted in lymphocyte cultures from vaccinees who had serum antibody rises after vaccination. The kinetics of these responses suggest that cell-mediated immunity may play a role in early events after infection and vaccination with influenza virus.
Antibody-Dependent Cytotoxicity Against
Trypanosoma rhodesiense
Mediated Through an Alternative Complement Pathway
Authors: Flemmings Barbara , Diggs Carter
Published: January 2020

A quantitative in vitro method was used to examine the role of classical and alternative pathways of complement activation in cytotoxicity against African trypanosomes by immune serum. This assay is based on the estimation of the extent of antibody-mediated cytotoxicity by measurement of inhibition of incorporation of [
3
H]leucine as an indicator of trypanosome metabolic integrity. To determine which pathway(s) is activated during cytotoxic events, complements sufficient in all components (C4S) and deficient in C4 (C4D) were used. Immune inhibition of [
3
H]leucine uptake by trypanosomes was observed in the presence of both complement sources. Treatment of C4S or C4D serum with cobra venom factor or disodium ethylenediaminetetraacetic acid abolished antibody-mediated cytotoxicity as well as immune hemolysis, thus suggesting the requirement for late-acting complement components. Ethyleneglycol-bis(β-aminoethyl ether)-
N,N
-tetraacetic acid had no effect on inhibition of leucine incorporation, whereas immune hemolysis was inhibited, suggesting that cytotoxicity did not require C1 activation, a Ca
2+
-dependent event. The dependence of the cytotoxic process on Mg
2+
and not Ca
2+
ions and the fact that C4D guinea pig serum is fully active in trypanosome cytotoxicity indicate that an alternative pathway of complement activation is sufficient for activity.
Influence of
Brucella
Endotoxins on the Initiation of Antibody-Forming Spleen Cells in Mice Immunized with Sheep Red Blood Cells
Authors: Renoux Gérard , Renoux Micheline , Tinelli Régina
Published: January 2020

Changes in the formation of antibodies to sheep red blood cells (sRBC) in the presence of
Brucella
extracts was studied in mice whose spleen cells were assayed by the Jerne procedure. Two strains of female mice were employed.
Brucella
extracts were prepared: (i) by trichloroacetic acid extraction (LPSN), (ii) by phenol extraction (LPS), and (iii) by hot acetic acid hydrolysis (Ps).
B. abortus
LPSN and
B. melitensis
LPSN or LPS, administered with sRBC, stimulated the specific response to sRBC, but only at high doses of endotoxins.
B. abortus
LPSN and
B. melitensis
LPSN suppressed nonspecific responses against horse red blood cells (hRBC), in contrast to the typical events following administration of
Serratia marcescens
endotoxin (or endotoxins from other ubiquitous organisms). In CD-1 mice,
B. abortus
Ps depressed the specific anti-sRBC response. Attempts to presensitize mice with
abortus
LPSN resulted in a stimulation of the response to sRBC, but pretreatment with
B. melitensis
LPSN had an inhibitory effect. When injected alone,
Brucella
endotoxins activated anti-sRBC antibody-forming cells but not anti-hRBC cells.
B. abortus
Ps was unable to modify the background number of anti-sRBC cells and inhibited the hRBC response. These data suggest (i) that there exists a “common antigen” between
Brucella
cells and sRBC and (ii) that the so-called primary response to endotoxins from ubiquitous organisms represents a secondary response to already naturally sensitized animals.
Immunity in Experimental Salmonellosis I. Protection Induced by Rough Mutants of
Salmonella typhimurium
Authors: Germanier R.
Published: January 2020

Different rough mutants of
Salmonella typhimurium
were tested to determine their virulence and immunizing capacity when used as live vaccines for mice. All uridine diphosphate-galactose-4-epimeraseless mutants tested were much more potent immunizing agents than any other mutants. This capacity was not correlated with virulence or complexity of cell wall polysaccharide. For good protection, persistence of the rough strains in vivo was essential, but the protection lasted longer than the period during which bacteria were demonstrable in the liver and spleen of the mice. The outstanding immunizing capacity of the “epimeraseless” mutants is not dependent on the persistence of viable bacteria in the mouse.
Immunofluorescence Studies on the Pathogenesis of Intestinal Chlamydial Infections in Calves
Authors: Eugster A. K. , Joyce B. K. , Storz J.
Published: January 2020

Newborn calves were exposed orally to the chlamydial agent of bovine polyarthritis. The chlamydial infection in the gastrointestinal tract was traced by reisolation of the agent and by fluorescent-antibody techniques. Absorption of the fluorescein isothiocyanate (FITC)-labeled antiserum with bovine fetal intestinal tissue powder eliminated effectively the nonspecific fluorescence of eosinophilic granules in intestinal tissue sections. Cells of the eosinophilic series were observed in great numbers in the gastrointestinal tract of inoculated and normal calves. Although chlamydial agents could be reisolated from mucosal scrapings of abomasum and duodenum for 5 days after inoculation, specific fluorescence was not observed in these gastrointestinal portions. As the chlamydial infection progressed, it localized in the mucosal epithelial cells of the jejunum and ileum. Fluorescing chlamydial inclusions were observed most consistently in the cytoplasm of mucosal epithelial cells on the tips of the jejunal and ileal villi. The inclusions were located between the nucleus and the free border of the epithelial cells. In the deeper parts of the villi, the inclusions in the epithelial cells were situated frequently between the nucleus and the basement membrane of the mucosal lamina propria. In calves examined 7 days after inoculation, fluorescing chlamydial inclusions were seen in the cells of the crypts and the mucosal lamina propria of the lower portions of the small intestine. Chlamydial infection of cells in the intestinal interstitium reflected a process of systemic invasion.
Immune reactivity of Visna virus-inoculated mice
Authors: Svennerholm B , Strannegård O , Lycke E
Published: January 2020

Visna virus inoculation of mice before immunization with unrelated antigens caused suppression of humoral and cell-mediated immune responses. The immunosuppressive effect was dependent on the virus dose and time of administration. The number of "background" antibody-producing spleen cells increased slightly after inoculation of Visna virus. Heat treatment of Visna virus abolished its immunosuppressive effect. Replication of Visna virus in mice seemed to be a prerequisite for its immunomodulating effect.
Cigarette smoke and phagocyte function: effect of chronic exposure in vivo and acute exposure in vitro
Authors: Thomas W R , Holt P G , Keast D
Published: January 2020

Phagocytic function was studied in mice chronically exposed to cigarette smoke, and the effects of in vitro exposure to cigarette smoke on macrophage activity were also assessed. Cultures of radiolabeled Pseudomonas aeruginosa were employed to investigate phagocyte activity in vivo and in vitro. Mice were exposed on weekdays to fresh cigarette smoke for periods up to 37 weeks and the bactericidal and clearance activity of their lungs was measured. Both pulmonary clearance and bactericidal activity was impaired. The clearance of intravenously injected bacteria from the blood of smoke-exposed mice occurred at the same rate as in control mice, but the accumulation of radiolabel by the liver was decreased. In addition, the rate of elimination of radiolabel from the liver was less than the controls. Macrophages exposed to cigarette smoke in vitro initially had a depressed phagocytic rate, but if phagocytosis over a prolonged period was measured it was eventually enhanced over the rate of control macrophages. The vapor phase of cigarette smoke could also transiently inhibit and then enhance the phagocytic activity.
Specific and nonspecific resistance in mice immunized with irradiated Myobacterium leprae
Authors: Patel P J , Lefford M J
Published: January 2020

Following subcutaneous inoculation of irradiated Mycobacterium leprae (I-ML) into the left hind footpad of mice, there was increased resistance to Listeria monocytogenes, indicative of macrophage activation, at the immunization site. In spite of the high level of localized macrophage activation which was proportioned to the immunizing dose of I-ML, no such activity could be demonstrated systemically in these mice, as evidenced by the absence of increased resistance to an intravenous challenge with L. monocytogenes. Under these conditions, I-ML-immunized mice were nonetheless resistant to intravenous infection with either M. tuberculosis or M. bovis BCG, and this immunity was transferred to normal recipients using spleen or lymph node cells. Neonatal thymectomy completely abolished the development of antimycobacterial immunity after vaccination with I-ML, but immunity was restored by an intraperitoneal infusion of syngeneic thymocytes. Systemic nonspecific resistance could be generated in I-ML-immunized mice by an intravenous injection of disrupted I-ML. This study reveals that, after subcutaneous vaccination with I-ML, there is local accumulation of activated macrophages at the inoculation site and a widespread distribution of lymphocytes which are sensitized to mycobacterial antigens. Nonspecific resistance is mediated by the former cells and specific antimycobacterial immunity by the latter.
Quantitative measurement of phagocytosis of Neisseria gonorrhoeae by mouse peritoneal macrophages
Authors: Jones R B , Buchanan T M
Published: January 2020

The simultaneous labeling of gonococci with [6-3H]uracil and of mouse peritoneal macrophages with L-[U-14C]leucine permits a quantitative assessment of the association of gonococci with macrophages under various experimental conditions. Colony-type T1 (piliated) gonococci associated more than T4 (nonpiliated) organisms at 4 degrees C, but at 37 degrees C the association of T4 gonococci with macrophages exceeded that for the T1 organisms. The association of T1 gonococci with macrophages could be enhanced as much as 70-fold by homologous rabbit antisera prepared against whole, formaldehyde-treated organisms. This immune enhancement represented primarily increased phagocytosis rather than surface attachment, as shown by its inhibition at 4 degrees C or with 2-deoxyglucose. The data further suggested that this enhanced phagocytosis was mediated via the Fc receptor for immunoglobulin G.
Demonstration of K88ac and K88ab antigens of Escherichia coli by means of immunoelectrophoresis and immunodiffusion
Authors: Cahill E E , Glantz P J
Published: January 2020

Five strains of Escherichia coli were tested for the presence of the K88ac or K88ab antigens by immunoelectrophoresis and immunodiffusion. The K88ac antigen of 0A2 and Sojka Abbotstown gave an anodic line in the immunoelectrophoresis test and a line in immunodiffusion with homologous K88ac antisera. The K88ab antigens of 0G7, 0E68, and Moon 263 also gave anodic lines in immunoelectrophoresis, and were detectable by immunodiffusions. The 0 groups of these strains were also demonstrated by immunoelectrophoresis and immunodiffusion with homologous 0 antisera. Lack of complete inactivation at 100 degrees C of both the K88ac and K88ab antigens was noted in this study.
Coupling of Escherichia coli lipopolysaccharide to epoxy-activated Sepharose 6B
Authors: Fox J , Hechemy K
Published: January 2020

Escherichia coli O111:B4 lipopolysaccharide was coupled to epoxy-activated Sepharose 6B. The bound lipopolysaccharide was immunogenic and immunoadsorptive although at less efficiency than free lipopolysaccharide.
Role of antibody and complement in opsonization of group B streptococci
Authors: Shigeoka A O , Hall R T , Hemming V G , Allred C D , Hill H R
Published: January 2020

A requirement for the classic complement pathway in opsonization of group B streptococci was observed by using both a chemiluminescence and a radiolabeled bacterial uptake technique. The classic pathway increased levels of opsonization for types Ia and II stock and wild strains and for some type III wild strains. In contrast, other type III wild strains and the type III stock strain had accelerated kinetics of uptake in the presence of an intact classic pathway, but the level of opsonization was unchanged from that with antibody alone. We could not demonstrate a significant role for the alternative pathway in opsonizing stock or wild strains of group B streptococci. Futhermore, electrophoretic and complement consumption analysis by hemolytic titration failed to reveal alternative pathway activation by the majority of strains of this group. Therapy aimed at supplying opsonins for these organisms will require the presence of type-specific antibody.
Adherence of Candida albicans to human buccal epithelial cells
Authors: Kimura L H , Pearsall N N
Published: January 2020

The adherence of Candida albicans to human buccal epithelial cells after 2 h at 37 degrees C was significantly greater in human saliva than in phosphate-buffered saline. in saliva, viable fungi adhered much better than did nonviable fungi, and this adherence was greater at 37 than at 25 degrees C. Viable yeasts, preincubated in saliva for 90 min at 37 degrees C before being washed and mixed with epithelial cells in phosphate-buffered saline, adhered better than nonviable yeasts or yeasts preincubated in phosphate-buffered saline. Enhanced adherence in saliva appeared to be associated with germination of the yeast cells. Conditions permitting germination (growth in tissue culture medium 199 at 37 degrees C but not at 25 degrees C) also supported enhanced adherence. After germination had occurred, the fungi could be killed with Formalin without interfering with their rapid and efficient adherence to epithelial cells. These data indicate that the enhanced adherence of C. albicans observed after incubation in saliva is related to changes in the fungi, rather than to a requirement for prolonged interaction between fungi and epithelial cells.
Structural analysis of the cellular constituents of a fresh clinical isolate of Staphylococcus aureus, and their role in the interaction between the organisms and polymorphonuclear leukocytes in the presence of serum factors
Authors: Karakawa W W , Young D A , Kane J A
Published: January 2020

The in vitro interaction of a fresh clinical isolate of Staphylococcus aureus and polymorphonuclear leukocytes was investigated. The importance of the various cellular constituents as host immunological factors was analyzed, and the results suggested that two components, namely, an acidic polysaccharide consisting of a predominance of aminogalacturonic acid and a strain-specific mucopeptide complex, may be involved in impeding in vitro opsonization of the organism by leukocytes. Immunochemical analysis indicated that the acidic polysaccharide possessed the same immunodominant aminogalacturonic acid residues as the antiphagocytic acidic antigen of the encapsulated prototype Scott strain. Antisera derived from rabbits immunized with strain D contained two types of opsonins, those with acidic polymer specificity and those with mucopeptide complex specificity.
Purification of tritium-labeled cholera toxin
Authors: Banwell J G , Hanke D W , Diedrich D
Published: January 2020

Cholera toxin was labeled with tritium by the Wilzbach technique, and highly purified radiolabeled toxin was obtained by Sephadex column chromatography and disc gel electrophoresis. 3H-labeled cholera toxin retained its biological activity and chemical stability and had a specific activity of 405.9 muCi/mumol. The methods utilized in extraction and purification of 3H-labeled toxin may be advantageous for preparation of other biologically active radiolabeled proteins.
Antiviral activity in interferon-treated bovine tracheal organ cultures
Authors: Fulton R W , Root S K
Published: January 2020

The effect of bovine interferon on the replication of infectious bovine rhinotracheitis virus and vesicular stomatitis virus in bovine tracheal organ cultures was studied. After treatment of tracheal organ cultures with interferon, inhibition of infectious bovine rhinotracheitis virus and vesicular stomatitis virus replication was observed. This tracheal organ system may be useful in determining the in vivo response to interferon for viral infections of the bovine respiratory tract.
Parameters affecting the enzyme-linked immunosorbent assay of immunoglobulin G antibody to a rough mutant of Salmonella minnesota
Authors: Bruins S C , Ingwer I , Zeckel M L , White A C
Published: January 2020

An enzyme-linked immunosorbent assay was developed to detect rabbit immunoglobulin G antibodies against purified lipopolysaccharide of the rough Re mutant of Salmonella minnesota. The time necessary for each step was investigated, and this resulted in a test that could be completed in 1 working day. Serial dilutions of rabbit sera drawn throughout immunization with the Re mutant revealed an elimination of the prozone effect upon prolonged immunization. We interpret this to demonstrate an increase in immunoglobulin G affinity for the lipopolysaccharide on prolonged immunization. We propose that the enzyme-linked immunosorbent assay prozone effect be investigated for use as a measure of antibody affinity.
Association of elevated levels of extracellular neuraminidase with clinical isolates of type III group B streptococci
Authors: Milligan T W , Baker C J , Straus D C , Mattingly S J
Published: January 2020

The level of total extracellular neuraminidase produced by 74 clinical isolates of group B streptococci isolated from diseased or asymptomatically colonized infants was assayed. Extracellular neuraminidase was obtained from concentrated filtrates of exponentially growing cultures of group B streptococci grown in a chemically defined medium (FMC) containing supplemental protein. The total activity of extracellular enzyme produced by these clinical isolates ranged from less than 10 to 360 nmol of sialic acid released per min per mg of cell dry weight. Strains were arbitrarily classified as either nonproducers (less than 10 nmol/min per mg of cell dry weight), low producers (greater than 10 to less than or equal 140 nmol/min per mg of cell dry weight), or high producers (greater than 140 to 360 nmol/min per mg of cell dry weight). Type III isolates from diseased infants were significantly more often classified as high producers than strains of group B streptococci of other serotypes from diseased infants (P less than 0.001). Furthermore, the serotype III strains isolated from neonatal infections were more often high producers than those of the same serotype from asymptomatically colonized infants (P less than 0.025). These results suggest that the ability to produce elevated levels of neuraminidase may be related to the frequent association of type III strains with disease among neonates.
Effects of iron and culture filtrates on killing of Neisseria gonorrhoeae by normal human serum
Authors: Norrod P , Williams R P
Published: January 2020

Neisseria gonorrhoeae GC9, both colony types T2 and T4, were killed by normal human serum, although populations of colony type T4 were more susceptible. Ferric ammonium citrate prevented the killing of populations of both T2 and T4 colony types. Other iron compounds tested showed no protective effect, nor did ammonium citrate or the divalent cations magnesium or calcium. A filtrate from cultures of an N. gonorrhoeae strain grown in a liquid defined medium showed a similar protective effect in the serum assay. The filtrate appeared to chelate iron, as measured by decreased ability of iron-free transferin to bind iron in the presence of the filtrate. However, the two effects did not appear to be related. Neither ferric ammonium citrate nor the culture filtrate sufficiently inactivated complement to account for protection.
Effect of specific antibody and complement on the survival of Rochalimaea quintana in vitro
Authors: Myers W F , Wisseman C L
Published: January 2020

No bactericidal effect was produced when Rochalimaea quintana was exposed for 1 h to a combination of high-titered anti-R. quintana rabbit serum and guinea pig complement.
Gamma-Irradiated Scrub Typhus Immunogens: Development and Duration of Immunity
Authors: Eisenberg George H. G. , Osterman Joseph V.
Published: January 2020

The development and duration of immunity to lethal scrub typhus infection was studied in BALB/c mice vaccinated with gamma-irradiated
Rickettsia tsutsugamushi
, strain Karp. One intraperitoneal injection containing approximately 10
8
50% mouse lethal doses (MLD
50
) of irradiated organisms elicited an immune response protective against challenge with 10
5
MLD
50
of viable Karp. The same mass of immunogen given in three injections at 5-day intervals increased homologous (Karp strain) protection 25-fold and heterologous (Kato strain) protection 60-fold. Further temporal expansion of the immunization regimen did not increase protection. Subcutaneous vaccination provided significant, but lower, levels of protection than were achieved by intraperitoneal immunization, but the levels of cell-transferable immunity elicited by the two routes were approximately the same. Immunologically specific protection after intraperitoneal vaccination developed rapidly enough to provide resistance against simultaneous challenge with 200 MLD
50
of Karp. Homologous immunity was protective against a 10
6
-MLD
50
challenge 7 days after completion of the three-injection regimen, remained at that level for 3 months, dropped to 10
4
MLD
50
by 9 months, and was effective against a 50-MLD
50
Karp challenge at 12 months. Protection against heterologous challenge was first observed on day 17 and peaked on day 38, when the mice resisted a 10
5
-MLD
50
Kato challenge. Thereafter, heterologous protection waned rapidly and was not significant at 6 months.
Experimental urinary tract infection with Pseudomonas aeruginosa in mice
Authors: Nishi T , Tsuchiya K
Published: January 2020

Urinary tract infection with Pseudomonas aeruginosa was induced in mice by transurethral inoculation of the organism into the bladder, followed by urethral obstruction for 6 h. The infection was mostly localized in the urinary organs. P. aeruginosa P9 was selected as the challenge organism from 10 laboratory strains of P. aeruginosa. After the inoculation of 10(7) colony-forming units of P. aeruginosa P9, transient bacteremia was observed in some of the mice from 6 h to 1 day after the inoculation. The number of organisms in the bladder tissue gradually decreased, whereas that in the kidneys increased to levels of 10(6) to 10(7) colony-forming units in 3 days, and these levels remained up to 2 weeks after the inoculation. The organisms gradually disappeared thereafter, and spontaneous recovery took place. The organisms could be recovered from the kidneys of 95% of the mice, and the gross lesions in the kidneys were observed in 77% of the mice 1 week after inoculation. The method developed here is simple and may be useful in the study of urinary tract infections due to P. aeruginosa and other species of bacteria.20
Contact sensitivity responses in mice infected with Trypanosoma cruzi
Authors: Reed S G , Larson C L , Speer C A
Published: January 2020

Mechanisms of depression of contact sensitivity responses in C57BL/10 mice infected with Trypanosoma cruzi were studied. Cellular involvement during sensitization with oxazolone was investigated in mice acutely infected with T. cruzi. Contact sensitivity was not expressed in mice during the latter stages of the acute infection. Spleen cells from sensitized, infected mice which were unable to respond to oxazolone could confer contact sensitivity upon normal syngenic mice as effectively as spleen cells from uninfected, sensitized donors. The ability of mice infected with T. cruzi to respond to an eliciting dose of oxazolone was significantly improved when macrophages from normal syngenic donors were administered to them at the time of skin test. When either normal or infected mice were used as recipients of lymphocytes from sensitized donors, the normal mice responded significantly better than did infected mice after administration of an eliciting dose of oxazolone. An increase in pyroninophilic cells was observed in draining lymph nodes after application of a sensitizing dose of oxaxolone to the ears of either normal or acutely infected mice. These results indicate that suppression of contact sensitivity during acute T. cruzi infection is directed toward the efferent arm rather than the afferent arm of the response.
Histocompatibility-linked genetic control of susceptibility to age-dependent polioencephalomyelitis in mice
Authors: Martinez D
Published: January 2020

Susceptibility to induction of immune polioencephalomyelitis (IPE) was found to be controlled by a gene that is closely linked to the H-2 complex. Whereas mice of the AKR (H-2k) strain were susceptible to IPE induction, H-2-congenic mice, AKR.H-2b (H-2b from C57BL/6) and AKR.M (H-2m), were resistant. However, susceptibility to IPE may be under additional control by a gene(s) outside of the H-2 region, since both C57BL/6 (H-2b) mice and congenic B6.H-2k mice (H-2k from AKR) were resistant to IPE induction. F1 hybrid mice derived from AKR (susceptible) and DBA/2 (resistant) mice were susceptible to IPE induction, indicating that susceptibility is dominant in at least one gene, but susceptibility developed at a later age in the hybrid mice than in AKR mice. B6.PL-Ly-2a Ly-3a/Cy, C57BR, C57L, PL, and RF strain mice were resistant to ipe induction. Thus, of the 12 inbred strains tested so far, only two (C58 and AKR) are susceptible to IPE.
Phage-related surface modifications of Pseudomonas aeruginosa: effects on the biological activity of viable cells
Authors: Dimitracopoulos G , Bartell P F
Published: January 2020

Lysogenic [EI(8)3] and phage 8-resistant mutant (EI/8S17) strains of Pseudomonas aeruginosa EI were isolated. Besides lacking the capacity to adsorb phage 8, strains EI(8)3 and EI/8s17 did not contain surface substrate for the depolymerase that is produced de novo when phage 8 infects wild-type strain. EI. The glycolipoprotein (GLP) in the wild type contains phage 8 receptors and surface substrate for the depolymerase, as well as possesses characteristics of a virulence factor; therefore, the chemical and biological characteristics of the derived strains were investigated. The neutral-sugar, amino sugar, and protein content of the GLPs from the derived strains differed quantitatively from that of the wild type. In spite of some cross-reactivity, the GLPs from all strains were antigenically distinct in the indirect hemagglutination inhibition test. In mice, the toxicity of the GLP from strain EI(8)3 equaled that of the wild type, but the GLP of strain EI/8s17 was threefold less toxic. Significantly fewer viable EI(8)3 cells were required for the mouse 50% lethal dose than for the cells of either the wild type or the phage-resistant mutant.
Delayed-type hypersensitivity against Semliki Forest virus in mice
Authors: Kraaijeveld C A , Harmsen M , Khader Boutahar-Trouw B
Published: January 2020

After intracutaneous immunization with purified inactivated Semliki Forest virus, a delayed-type hypersensitivity without detectable antibodies in serum was obtained in BALB/c mice. Low doses of antigen given intraperitoneally induced antibodies. Intracutaneous immunization with much higher doses induced no specific antibodies, but a footpad swelling was observed after challenge with homolgous antigen. Pretreatment with cyclophosphamide before immunization enhanced footpad swelling. Microscopic examination of footpads from sensitized mice at 24 h after challenge showed a mononuclear infiltrate. The delayed-type reaction could be transferred to syngenic mice with lymph node cells, but not with spleen cells or serum. The biphasic character of the delayed-type hypersensitivity is discussed.
Transfer by bone marrow cells of increased natural resistance to Klebsiella pneumoniae induced by lipopolysaccharide in genetically deficient C3H/He mice
Authors: Galelli A , le Garrec Y , Chedid L
Published: January 2020

In a previous study we demonstrated that lipopolysaccharide failed to elicit nonspecific resistance in C3H/He lipopolysaccharide low-responder mice against Klebsiella infection in contrast to its activity in a closely related histocompatible high-responder subline, C3HeB/Fe. Complete restoration of lipopolysaccharide-induced protection against 10(5) Klebsiella was obtained in the present study by transferring bone marrow from high-responder mice to the highly deficient C3H/He mice. The ability of C3H/He mice to clear and destroy bacteria in 5 h was also transferred by C3HeB/Fe marrow cells. In contrast, when high-responder C3HeB/Fe mice were reconstituted with low-responder bone marrow, the clearance and destruction of K. pneumoniae were similar to what is observed in the high-responder strain, but survival was only temporary. Collectively, our data show that the failure of C3H/He mice to respond to lipopolysaccharide with nonspecific immunity is due to a defect in two types of bone-marrow-derived cells--radioresistant and radiosensitive.
Restoration of T-cell responsiveness by thymosin: expression of anti-tuberculous immunity in mouse lungs
Authors: Collins F M , Morrison N E
Published: January 2020

Specific pathogen-free, adult thymectomized, irradiated, and bone marrow-reconstituted (THXB) B6D2 mice were infected aerogenically with 1 X 10(3) to 5 X 10(3) live BCG Pasteur. Seven days later a group of the mice was placed on a 14-day regimen of 20 mg of calf thymosin per kg per day, and the growth of the BCG in the lungs, spleen, inguinal lymph node, bone marrow, and blood was determined for up to 90 days. The thymosin treatment was followed by a decline in the BCG counts for the lungs and spleens of the THXB mice, whereas the saline-treated controls showed no such decline with time. The thymosin-treated mice did not develop progressive BCG infections in the test lymph nodes or in the bone marrow, both of which became positive in the THXB mice. Spleen cells were harvested from thymosin-treated THXB donors, filtered through nylon wool, and infused three times into BCG-infected THXB recipients. The lung BCG counts declined approximately 10-fold by day 90 compared with THXB mice which received THXB spleen cells. The transferred immune response was only slightly smaller numerically than that seen in THXB mice infused with BCG-immune lymphocytes from normal donors.
Capacity of virulent Treponema pallidum (Nichols) for deoxyribonucleic acid synthesis
Authors: Baseman J B , Nichols J C , Mogerley S
Published: January 2020

Treponema pallidum (Nichols) was extracted from infected rabbit tissue, and cell lysates were prepared for monitoring thymidine kinase and deoxyribonucleic acid polymerase activities. No thymidine kinase could be demonstrated in preparations of T. pallidum or the cultivable T. phagedenis biotype Reiter. Significant levels of deoxyribonucleic acid polymerase were detected in both treponemal samples. Interestingly, comparisons of polymerase activity among a spectrum of bacterial genera revealed a direct correlation between enzyme concentrations and estimated generation time. Incorporation of [3H]uridine and [3H]thymidine into macromolecules by intact T. pallidum and the Reiter treponeme was examined. Selective ribonuclease-deoxyribonuclease digestion and cesium chloride gradient banding demonstrated that T. pallidum, independent of the host, and T. phagedenis were capable of synthesizing deoxyribonucleic acid only from the [3H]-uridine precursor.