bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunoglobulin responses to Coxiella burnetii (Q fever): single-serum diagnosis of acute infection, using an immunofluorescence technique
Authors: Hunt J G , Field P R , Murphy A M
Published: January 2020

Blood specimens were collected over various periods of time from 30 abattoir workers with a clinical diagnosis of Q fever. All specimens were tested for complement-fixing antibodies and for specific immunoglobulin M (IgM) globulins to phase 1 and 2 Coxiella burnetii organisms by an immunofluorescence technique. All 22 patients with increasing levels of complement-fixing antibodies were shown to have generated specific IgM globulins, as did 4 patients with high convalescent titers but from whom "acute" specimens were not collected. Four individuals who did not show increasing levels of complement-fixing antibodies did not produce measurable levels of specific IgM. All patients with Q fever gave positive specific IgM results by 2 weeks after the onset of symptoms. IgM to phase 1 antigen persisted for 27 weeks in one patient, but IgM to phase 2 antigen was not detectable beyond 17 weeks. The estimation of Q fever-specific IgM has proved useful in confirming infection when only a "convalescent" blood specimen is available.
Correlation of level and duration of Streptococcus mutans infection with incidence of dental caries
Authors: Zickert I , Emilson C G , Krasse B
Published: January 2020

The caries incidence at various levels of Streptococcus mutans infection was analyzed in a control group and a test group. In the control group, the incidence of caries and the duration of S. mutans infection were significantly correlated. In the test group, the S. mutans infection was suppressed by antimicrobial measures when the number of S. mutans exceeded 250 X 10(3) CFU per ml of saliva. The results illustrate that the level and duration of the S. mutans infection are strongly correlated to the incidence of caries. The findings support the concept of S. mutans as a key cariogenic microorganism and illustrate the value of antimicrobial treatment in the prevention of caries.
Protection against pneumococcal infection in mice conferred by phosphocholine-binding antibodies: specificity of the phosphocholine binding and relation to several types
Authors: Szu S C , Clarke S , Robbins J B
Published: January 2020

Some anti-phosphocholine antibodies protect mice against challenge with certain, but not all, pneumococcal types. We found that both their isotype and reactivity with the cell wall C-polysaccharide of encapsulated pneumococci, as measured by immunodiffusion, were important in predicting the protective activity of anti-phosphocholine antibodies. We propose that the specificity of the protective antibodies includes the backbone of the phosphocholine-containing structure.
Simple model for the study of Pseudomonas aeruginosa infections in leukopenic mice
Authors: Cryz S J , Fürer E , Germanier R
Published: January 2020

A simple, reproducible model of fatal Pseudomonas aeruginosa sepsis in mice during immunosuppression was developed. Mice were rendered leukopenic (less than or equal to 800 leukocytes per mm3 of blood) for a period of 5 days by multiple injections of cyclophosphamide. Mice were challenged at the onset of leukopenia by instilling the bacteria onto a 0.5-mm incision made into the back. The mean lethal dose (LD50) for P. aeruginosa PA220 and M-2 was less than 20 bacteria. The mean time to death for these strains ranged from 46 to 59 h. Leukopenic mice were comparatively resistant when challenged with Klebsiella pneumoniae (LD50 = 1.5 x 10(6)) or Staphylococcus aureus (LD50 greater than 10(6)). Infection with P. aeruginosa was characterized by rapid bacterial multiplication in the skin at the site of infection, producing ecthyma gangrenosum. Bacteremia and colonization of the liver were pronounced 21 h postinfection. This model should prove to be a useful tool for studying the pathogenesis of P. aeruginosa infections under immunosuppressed conditions.
Protection against Pseudomonas aeruginosa infection in a murine burn wound sepsis model by passive transfer of antitoxin A, antielastase, and antilipopolysaccharide
Authors: Cryz S J , Fürer E , Germanier R
Published: January 2020

The protective capacity of passively transferred immunoglobulin G (IgG) fractions from antitoxin (AT-IgG), antielastase (AE-IgG), and antilipopolysaccharide (ALPS-IgG) against Pseudomonas aeruginosa infection was evaluated in a murine burn wound sepsis model. Complete protection was afforded by homologous ALPS-IgG against intermediate challenge doses (10 50% lethal doses) of P. aeruginosa PA220, whereas AT-IgG and AE-IgG offered no significant protection (P less than 0.5). The simultaneous transfer of AT-IgG or AE-IgG with ALPS-IgG gave no additional protection above that seen with ALPS-IgG alone. The transfer of ALPS-IgG did not dramatically alter bacterial multiplication in the skin at the site of infection. However, bacteremia and infection of the liver were prevented. In parallel experiments, AT-IgG or AE-IgG did not significantly alter either the course of the infection or the number of bacteria seen in the blood, liver, or skin when compared with controls. ALPS-IgG administered 24 h before infection, at the time of infection, or 4 h postinfection provided complete protection. Even when ALPS-IgG was transferred at a time when the infection was well established locally in the skin (8 h postinfection), highly significant protection (P greater than 0.999) was obtained. Protection afforded by ALPS-IgG was serotype specific. These results indicate that antibody to lipopolysaccharide is of critical importance for protection against P. aeruginosa challenge in a relevant animal model.
Inhibition of
Mycoplasma pneumoniae
Hemadsorption and Adherence to Respiratory Epithelium by Antibodies to a Membrane Protein
Authors: Krause Duncan C. , Baseman Joel B.
Published: January 2020

Antiserum and purified immunoglobulin directed against
Mycoplasma pneumoniae
membrane protein P1 were examined for their influence on mycoplasma viability, metabolism, and cytadsorption. Anti-P1 immunoglobulin inhibited adherence of
M. pneumoniae
to hamster tracheal rings in vitro by up to 80% and inhibited hemadsorption by greater than 90%. Cytadsorption was also inhibited by anti-P1 Fab fragments. Anti-P1 antibodies had no effect on
M. pneumoniae
viability or metabolism. The data indicate that anti-P1 antibody obstructs the interaction of
M. pneumoniae
adhesin P1 with its host receptors.
Dissociation of a hydrophobic surface from phagocytosis of encapsulated and non-encapsulated cryptococcus neoformans
Authors: Kozel T R
Published: January 2020

Cryptococcus neoformans is surrounded by a capsular polysaccharide that inhibits phagocytosis of the yeast by macrophages. This capsular polysaccharide also confers several physicochemical properties to the cell surface, including a negative surface charge and a hydrophilic surface. The present study was designed to determine whether a hydrophobic surface was necessary or sufficient for phagocytosis of C. neoformans cells. The hydrophobic nature of the cell surface was measured by hydrophobic interaction chromatography on octyl-Sepharose. Liability to phagocytosis was determined by use of mouse peritoneal macrophages. The surface properties of C. neoformans cells were modified by (i) preincubation of cryptococcal cells with nonimmune serum or immune anticapsular serum, (ii) chemical modification of the carboxyl and O-acetyl groups in the capsular polysaccharide, and (iii) use of various serotypes of C. neoformans with different degrees of O-acetyl and xylosyl substitution. The results showed that it was possible to experimentally vary the surface hydrophobic-hydrophilic characteristics of the cell surface; however, the antiphagocytic character of the capsule remained unchanged. The results further suggest that a hydrophobic surface was neither necessary nor sufficient for phagocytosis of C. neoformans cells by macrophages.
Molecular factors associated with virulence of marine vibrios isolated from striped bass in Chesapeake Bay
Authors: Toranzo A E , Barja J L , Potter S A , Colwell R R , Hetrick F M , Crosa J H
Published: January 2020

On the basis of cultural and biochemical properties as well as DNA homology assays, 81 Vibrio strains isolated from diseased striped bass and from Chesapeake Bay water were assigned to eight distinct groups. All organisms belonging to two of the groups were pathogenic for striped bass and were identified as Vibrio anguillarum, whereas organisms classified in the other six groups were nonpathogenic and were designated as Vibrio spp. Unlike the pathogenic V. anguillarum strain 775 isolated in the Pacific Northwest, strains pathogenic for striped bass did not contain any plasmids; however, they were similar to the Northwest isolates in that virulence was correlated with their ability to grow in the presence of nonimmune striped bass serum or under conditions of iron limitation. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of outer membranes showed that additional proteins were induced in those organisms capable of growth under conditions of iron limitation. It was of interest that 22 of the nonpathogenic isolates harbored one or more plasmids which, by restriction endonuclease analyses, were shown to be clearly different from the virulence plasmid pJM1.
Partial purification and characterization of an escherichia coli toxic factor that induces morphological cell alterations
Authors: Caprioli A , Falbo V , Roda L G , Ruggeri F M , Zona C
Published: January 2020

A factor produced by several strains of Escherichia coli isolated from enteritis-affected children has been shown to produce both a necrotizing effect on rabbit skin and striking morphological alterations on CHO, Vero, and HeLa cells. The same strains were found to have hemolytic activity on sheep erythrocytes. The toxic, cell-altering factor was demonstrated to be different from both heat-labile and heat-stable enterotoxins and from Vero toxin. The main effect induced by the isolated factor on cultured cells was the formation of large multinucleated cells. The partial purification achieved suggests that the same factor (most likely a protein with a molecular weight of 70,000 to 80,000) is responsible for toxic and cell-altering activities, whereas a different molecular species is responsible for hemolytic activity.
Pseudomembranous colitis in Clostridium difficile-monoassociated rats
Authors: Czuprynski C J , Johnson W J , Balish E , Wilkins T
Published: January 2020

Germfree rats were monoassociated with either a toxin-producing strain of Clostridium difficile (Tox+) or a variant of this strain (ToxR) which produced much less toxin (1/10,000) in vivo and in vitro. Monoassociation of germfree rats with C. difficile Tox+ resulted in mortality (17%) and in pathology to the small and large intestines, livers, and lungs. Cecal filtrates from the Tox+-monoassociated rats were cytotoxic for tissue culture cells. The cytotoxicity of cecal filtrates could be blocked by sera from Tox+-monoassociated rats. Monoassociation of rats with C. difficile ToxR resulted in no deaths or pathology, and much less toxin was detected in the cecal filtrates of these animals than in those of rats colonized with the Tox+ strain. This gnotobiotic model may be useful for investigating the etiology, prophylaxis, therapy, and exacerbation of C. difficile-induced pseudomembranous colitis.
Correlation of host immune response with quantitative recovery of Chlamydia trachomatis from the human endocervix
Authors: Brunham R C , Kuo C C , Cles L , Holmes K K
Published: January 2020

We studied 95 women with uncomplicated Chlamydia trachomatis cervical infection. Quantitative isolation of C. trachomatis was performed in HeLa 229 cells, and the results were correlated with serum immunoglobulin M and immunoglobulin G antibody to the organism. We found that quantitative cultures for C. trachomatis can provide a meaningful measurement by which to evaluate the effect of the acquired immune response. In particular, secretory immunoglobulin A antibody to C. trachomatis in cervical secretion demonstrated a striking and inverse correlation with recovery of the organism from the cervix. It is suggested that this component of the immune response may regulate shedding of the organism.
Histamine Release in the Dog After Leukocyte Lysate Injection
Authors: Kelly Michael T. , Brashear Richard E. , Martin R. Russell , White Arthur
Published: January 2020

Mixed leukocyte suspensions, containing 10
6
leukocytes per ml, were prepared from dog peripheral blood by dextran sedimentation. Lysates of these suspensions, prepared by sonification, were administered intravenously to the autologous dogs. The plasma histamine levels were increased to an average value 320% above the control values (
P
< 0.001). The individual elements in the mixed leukocyte suspensions were separated by sucrose gradient and glass bead column fractionation procedures, and purified suspensions of platelets (no other formed elements present), lymphocytes (95 to 100%), and granulocytes (90 to 98%) were obtained. Lysates of these suspensions all had significant histamine-releasing activity when administered intravenously to dogs. Although leukocytes and platelets from other species are known to harbor mediators of histamine release, this study provides the first demonstration of the histamine-releasing activity of dog leukocytes and platelets. Many of the studies of leukocyte and platelet histamine-releasing factors have employed in vitro systems leaving the in vivo role of these factors in doubt. The present studies provide evidence that leukocyte and platelet histamine-releasing factors have in vivo activity.
United States Standard Diphtheria Toxin for the Schick Text and the Erythema Potency Assay for the Schick Text Dose
Authors: Barile Michael F. , Kolb Robert W. , Pittman Margaret
Published: January 2020

A diphtheria toxin shown to have high toxicity and avidity and to combine with antitoxin in multiple proportions was selected for the U.S. standard diphtheria toxin for the Schick test and freeze-dried. Assayed values per vial were 1.09 L
f
, 1.09 L
r
, 1,090 Schick test doses (STD), 33 LD
80
, 38 LD
50
, and 43,000 minimum skin reactive doses. One STD (L
r
/1000) is slightly more toxic than one unit of the international standard (L
f
/1,000). Experiments showed that the potency assay of Schick test toxin by guinea pig erythema toxicity, determined relative to the toxicity of the standard, was highly reproducible and significantly more reproducible than the lethal (minimum lethal dose) test and that the STD, defined as one L
r
/1000, was equivalent to approximately 1/50 minimum lethal dose. The erythema potency assay was prescribed in the U.S. standards for Schick test toxin effective in 1969.
Ultraviolet Light Inactivation and Photoreactivation in the Mycobacteria
Authors: David Hugo L. , Jones Wilbur D. , Newman Carol M.
Published: January 2020

The kinetics of inactivation of mycobacteria by ultraviolet light were investigated.
Mycobacterium tuberculosis
and
M. marinum
were shown to be capable of photo-reactivation.
Enzyme Activities of the Livers of Mice Infected with
Salmonella typhimurium
Authors: Snyder Irvin S.
Published: January 2020

The activities of the mouse liver enzymes tryptophan oxygenase, tyrosine aminotransferase, and pyruvate kinase were measured after infection with three dose levels of
Salmonella typhimurium
strain SR-11. Infection occurred in all groups as evidenced by an increase in bacterial numbers and by death of the animals. The activities of the enzymes increased in all groups during the course of the infection. The results obtained during infection are compared with those obtained after endotoxin injection.
Inhibition of
Pseudomonas aeruginosa
by Hyperbaric Oxygen II. Ultrastructural Changes
Authors: Clark Junius M. , Pakman Leonard M.
Published: January 2020

The ultrastructure of
Pseudomonas aeruginosa
cells treated with hyperbaric oxygen for 20 to 24 hr was examined by electron microscopy. A marked difference in the morphology of the nuclear area and cytoplasm of experimental cells was noted when compared to control cells grown under normobaric conditions. This difference was characterized by the absence of a definitive nuclear area and a reduced granularity of the cytoplasm.
Anaerobic Bacteria on the Mucosal Epithelium of the Murine Large Bowel
Authors: Savage Dwayne C. , McAllister Julia S. , Davis C. Patrick
Published: January 2020

Anaerobic bacteria can be detected at population levels of 10
11
organisms per g of cecum or colon in adult mice from four different colonies widely spaced in the United States. Most of these microorganisms are oxygen-intolerant fusiform-shaped bacteria. At least one type of these tapered, rod-shaped bacteria can be seen in layers in the epithelial mucin in frozen-section histological preparations of the large bowels of mice. In addition, such microorganisms can be seen within 0.5 μm of the epithelium in ultrathin sections of colon or cecum examined in an electron microscope. These fusiform-shaped bacteria predominate in the mucin layers. However, spiral-shaped microorganisms can be found as well near the mucosal epithelia in ultrathin sections of colon. Also, such organisms can be seen in negatively-stained preparations of washings of the colonic mucosal epithelia examined in an electron microscope. At least three types of spiral-shaped organisms, including both spiral-shaped bacteria and spirochetes, can be found in preparations from mice from three of the four colonies. Such spiral-shaped microorganisms can be detected at population levels as great as 10
9
organisms per g of cecum or colon in anaerobic cultures of the large bowels of mice from all four colonies. One anaerobic spiral bacterium was isolated in pure culture. This particular organism was found by immunofluorescence to be intermingled with the fusiform-shaped bacteria in the mucin on the mucosal epithelium in the mouse large bowel.
Influence of Oxidation and Reduction on the Acid-Fastness of Mycobacteria
Authors: Nyka W.
Published: January 2020

Experiments are described in which the acid-fastness of mycobacteria was destroyed by reduction and restored by oxidation.
Tissue Amino Acid Flux After Exposure of Rats to
Diplococcus pneumoniae
Authors: Wannemacher R. W. , Powanda M. C. , Pekarek R. S. , Beisel W. R.
Published: January 2020

The concentration of 21 individual free amino acids in serum, liver, and skeletal muscle was determined in rats during the incubation, acute illness, and terminal stages of experimental infection with
Diplococcus pneumoniae
. By 4 hr after subcutaneous inoculation with bacteria, the concentration of total and many individual free amino acids in serum, liver, and muscle was significantly decreased in comparison to findings in noninfected, pair-fed control rats. By use of a nonmetabolizable amino acid analogue (cycloleucine), it was possible to detect a flux of amino acids from muscle to liver in the infected rat. The endogenous amino acids which moved to the liver were rapidly utilized for the synthesis of serum proteins.
Enhancement of Phagocytosis by Interferon-Containing Preparations
Authors: Huang Kun-Yen , Donahoe Robert M. , Gordon Francis B. , Dressler Harry R.
Published: January 2020

Exposure of mononuclear cells from the mouse peritoneal cavity to interferon (IF)-containing mouse sera enhanced phagocytosis of colloidal carbon particles by the cells. The same effect was observed when the cells were exposed to IF-containing cell culture harvest free of serum. The magnitude of this effect of IF-containing preparations paralleled the titer of IF and was not related to the dilution of various IF-containing serum specimens tested. The factor responsible for the enhancing effect was stable at
p
H 2, inactivated by trypsin, and nonsedimentable at 105,000 ×
g.
Heating at 60 C for 1 hr destroyed it, and its kinetics of heat inactivation paralleled that of the antiviral activity of IF. A period of incubation of phagocytic cells with IF-containing serum was necessary before a maximum level of enhancement was reached, and once established was not removable by repeated washing of cells. The kinetics of the production of the enhancing factor in mice injected with Newcastle disease virus was essentially identical to that of the simultaneous production of IF as measured by antiviral activity. Contrary to the effect of mouse IF preparations, human IF preparation did not enhance the activity of mouse phagocytes. It appears, therefore, that the phagocytosis-enhancing factor falls within the present definition of IF.
Inhibition of Influenza Virus and Interferon Response Intranasally with Statolon
Authors: Kleinschmidt W. J. , Streightoff Frank
Published: January 2020

Statolon, an interferon inducer, when instilled intranasally (IN) protects mice infected with lethal doses of influenza virus via the same route 16 hr later. The existence of interferon has been demonstrated in the trachea and lungs of mice treated IN with statolon, and it is assumed that the protection observed is due to this inhibitor. A dose response is seen with statolon administered IN. The protective activity of statolon instilled IN prophylactically lasts 1 to 2 weeks against influenza virus. Repeated doses of statolon, as many as four, a week apart, are effective. Antigenicity of the statolon (mycophage) particle relative to neutralization of its interferon-inducing capacity, therefore, may not prove to be a problem in clinical testing of this type of interferon inducer. The observed duration of activity of statolon also eliminates the possibility of difficulty due to hyporeactivity of the inducer.
Human Interferon-γ Enhances the Expression of Class I and Class II Major Histocompatibility Complex Products in Neoplastic Cells More Effectively than Interferon-α and Interferon-β
Authors: Dolei Antonina , Capobianchi Maria R. , Ameglio Franco
Published: January 2020

Human interferon-γ was more effective than interferon-β or -α in stimulating production of immunoassociated antigens; HLA-A, -B, and -C; and β
2
-microglobulin in human M14 and Namalva cells. The comparison was made on the basis of antiviral units, and the stimulation could be abolished by treatment of the interferon-γ preparation with pH 2 or anti-interferon-γ serum.
Specificity in the immunosuppression induced by avian reticuloendotheliosis virus
Authors: Walker M H , Rup B J , Rubin A S , Bose H R
Published: January 2020

Several parameters of the cellular and humoral immune responses of chickens infected with reticuloendotheliosis virus (REV-T), an avian defective acute leukemia virus, or with its helper virus, reticuloendotheliosis-associated virus (REV-A), were evaluated. Spleen cells from chickens infected with REV-T (REV-A) or REV-A exhibited depressed mixed lymphocyte and mitogen responses in vitro. Allograft rejection was delayed by 6 to 14 days in birds infected with REV-A. The specific antitumor cell immune response was also studied by a 51Cr-release cytotoxicity assay. Lymphocytes from chickens infected with low numbers of the REV-T-transformed cells exhibited significant levels of cytolytic reactivity against the 51Cr-labeled REV-T tumor cells in vitro. The mitogen response of lymphocytes from these injected birds was similar to that of uninjected chickens. In contrast, lymphocytes from chickens injected with higher numbers of REV-T-transformed cells exhibited suppressed mitogen reactivity and failed to develop detectable levels of cytotoxic activity directed against the REV-T tumor cells. These results suggest that the general depression of cellular immune competence which occurs during REV-T (REV-A) infection could contribute to the development of this acute leukemia by inhibiting the proliferation of cytotoxic cells directed against the tumor cell antigens. The cytotoxic effect observed after the injection of chickens with non-immunosuppressive levels of REV-T-transformed cells appears to be specific for the REV-T tumor cell antigens since cells transformed by Marek's disease virus or avian erythroblastosis virus were not lysed. In marked contrast, birds whose cellular immune responses were suppressed by infection with REV-A were capable of producing a humoral immune response to viral antigens. Detectable levels of viral antibody, however, did not appear until 12 to 15 days after REV-A infection. Since REV-T (REV-A) induced an acute leukemia resulting in death within 7 to 14 days, it appears unlikely that the ability of chickens to make antiviral antibody influences the development of lethal reticuloendotheliosis.
Ascending, unobstructed urinary tract infection in mice caused by pyelonephritogenic Escherichia coli of human origin
Authors: Hagberg L , Engberg I , Freter R , Lam J , Olling S , Svanborg Edén C
Published: January 2020

A model for ascending unobstructed urinary tract infection was developed in mice to study the pathogenesis of urinary tract infection induced by Escherichia coli associated with urinary tract infection in humans. Specifically, the model was designed to monitor the initial stages of the infectious process, e.g., bacterial adhesion. Mice were selected since the specificity and intensity of bacterial attachment of pyelonephritogenic E. coli strains to human and mouse uroepithelial cells were similar. Female mice were infected by urethral catheterization and installation of bacteria in the urinary bladder. To maximize clearance of unattached bacteria, no obstructive manipulations were performed. After sacrifice, the persistence of bacteria in kidneys and bladder was determined by viable counts on homogenized tissues. The experimental infection was standardized by using one pyelonephritis (HU734) and one normal fecal (414) E. coli isolate. With both strains all of the bladders became infected, but E. coli 414 was eliminated more rapidly than HU734. The percentage of positive kidney cultures increased with the bacterial inoculum concentration and volume. An inoculum of 0.05 ml containing 10(10) bacteria per ml was selected, giving the highest percentage of positive kidney cultures without detectable bacterial spread to the blood stream. The variation in the percentage of positive kidney cultures possibly depended on the degree of vesicoureteric reflux in the individual animals. Both in the kidneys and in the urinary bladders, strain HU734 yielded higher numbers of bacteria at 24 h and persisted longer than did strain 414. Several E. coli pyelonephritis isolates with properties associated with virulence in the human urinary tract consistently were recovered from mouse kidneys and bladders in higher numbers than E. coli strains of human fecal origin lacking those properties. The role of bacterial adhesion per se is the topic of the accompanying paper.
Release of Shiga Toxin from
Shigella dysenteriae
1 by Polymyxin B
Authors: Griffin Darrell E. , Gemski P.
Published: January 2020

Release of Shiga toxin from
Shigella dysenteriae
1 was found to occur after exposure to polymyxin B. The amount of toxin released was dependent on both the polymyxin concentration and time of incubation. An immunoblot characterization of the Shiga toxin released by polymyxin treatment demonstrated that it is electrophoretically similar to purified Shiga toxin and to Shiga toxin present in crude bacterial sonicates of
S. dysenteriae
1 cells.
Lymphocyte subsets and natural killer cell responses during cytomegalovirus mononucleosis
Authors: Rinaldo C R , Ho M , Hamoudi W H , Gui X E , DeBiasio R L
Published: January 2020

Cell-mediated immunity in seven patients with cytomegalovirus mononucleosis was assessed by monoclonal antibody to lymphocyte subsets, lymphocyte blastogenesis, and natural killer cell activity. The patients had decreased ratios of helper (Leu 3a) to suppressor-cytotoxic (Leu 2a) T cells as compared with normal donors. Leu 2a+ T cells from the patients were uniquely sensitive to overnight culturing, which resulted in a 2.6-fold increase in the helper/suppressor cell ratio and the appearance of an unusual third Leu 1+ 2a- 3a- T cell subset. This correlated directly with enhanced blastogenesis to concanavalin A after preculture. Base-line and interferon-boosted natural killer cell responses versus K562 cell targets during cytomegalovirus mononucleosis did not differ from those of normal donors. This suggests that certain cellular immune functions are depressed during cytomegalovirus mononucleosis in correlation with the emergence of a culture-sensitive subset of suppressor T cells. In contrast, cytotoxic lymphocytes appear to function normally and may aid in the resolution of the illness.
Increase in immunoglobulin M antibodies against gut bacteria during acute hepatitis A
Authors: Miller H F , Legler K , Thomssen R
Published: January 2020

The marked increase in the total serum immunoglobulin M (IgM) is a characteristic feature of acute hepatitis A. To study the nature of this IgM, we assayed serial titers of IgM antibodies against various antigens during and after acute hepatitis A. The antibodies against blood group antigen remained unchanged throughout the observation period. Thus, the production or metabolism of IgM was not nonspecifically altered. The IgM antibody against hepatitis A antigen decreased and finally disappeared during convalescence as expected. However, its time course did not correlate quantitatively with the concentration of the total serum IgM. In contrast, IgM antibodies against gut bacteria Bacteroides fragilis and Streptococcus faecalis were considerably elevated in all patients at the onset of the disease, and they normalized similarly to the total IgM during convalescence. IgM antibodies against Escherichia coli were elevated only in some of the patients. The data suggest that the amount of IgM antibodies against gut bacteria contributes significantly to the increase in the total serum IgM in acute hepatitis A.
Conformity between heat-labile toxin genes from human and porcine enterotoxigenic Escherichia coli
Authors: Dallas W S
Published: January 2020

The genes encoding the heat-labile toxin of Escherichia coli were isolated by recombinant DNA methods from enterotoxigenic E. coli recovered from a human and a piglet with diarrhea. With restriction endonucleases, a fine-structure map was made for the toxin genes. Both genes were found to be highly homologous within the toxin-coding DNA, but the surrounding DNA sequences were found to be quite divergent. Analysis of in vitro-derived mutants demonstrated that the cistrons for the toxin proteins were located at the same sites on each restriction enzyme map.
Potency of bactericidal proteins purified from the large granules of bovine neutrophils
Authors: Gennaro R , Dolzani L , Romeo D
Published: January 2020

The novel population of large granules of bovine neutrophils, which is the cell store of bactericidal activity independent of O2 derivatives, was extracted with an acid medium. Several fractions were resolved from the extract by ion-exchange chromatography (with carboxymethyl-cellulose) and gel filtration (with Sephadex G-50). Some of these fractions contained only a very limited number of major components, as detected by polyacrylamide gel electrophoresis. The purified bactericidal proteins exhibited their activity at 0.1 to 10 micrograms/0.3 ml of assay mixture containing 1 X 10(6) to 2 X 10(6) CFU of Staphylococcus aureus or Escherichia coli in media with physiological concentrations of Na+, K+, Mg2+, and Ca2+. Two fractions, containing polypeptides with apparent molecular weights ranging from 28,000 to less than 12,000, caused rather selective and rapid (5 to 20 min) killing of S. aureus. Their action was accompanied by significant binding to the gram-positive bacteria of some low (less than 12,000)-molecular-weight components. Other Sephadex G-50 fractions, containing the first emerging proteins with relatively high molecular weights, were more active on E. coli than on S. aureus. With the gram-negative bacteria there was a 10-min delay in the onset of bactericidal activity, which thereafter developed very fast. On the basis of the in vitro potency of the large-granule bactericidal proteins, we suggest that even partial discharge of granule content into the phagosomes may supply the phagocytic vacuoles of bovine neutrophils with a very efficient nonoxidative bactericidal system acting on both gram-positive and gram-negative microorganisms.
Specific absence of type 2 fimbriae on a coaggregation-defective mutant of Actinomyces viscosus T14V
Authors: Cisar J O , Curl S H , Kolenbrander P E , Vatter A E
Published: January 2020

The coaggregation-defective (COG-) mutant Actinomyces viscosus T14V(PK455), which is unable to participate in lactose-sensitive adherence, and its COG+ parent were compared to structurally define the mutational loss of cell-associated lectin activity. Immunoelectrophoretic comparisons of crude extracts or isolated fimbriae from both strains demonstrated type 2 fimbriae (previously designated Ag2) in preparations obtained from the parent but none in those obtained from the mutant. This result was verified by the immunoelectron-microscopic identification of type 1 (previously designated Ag1 or VAl) and type 2 fimbriae on the parent organism but only type 1 fimbriae on the mutant. A comparison of the amounts of extractable fimbriae of each type and the capacity of the cells to bind 14C-labeled monoclonal antibodies specific for each fimbrial component showed that the mutational loss of type 2 fimbriae had no significant quantitative effect on fimbriation of the COG- mutant with type 1 structures. Cells of A. viscosus T14AV, a mutant with various adherence defects that include the COG- phenotype, displayed fimbriae of both types, but in greatly reduced amounts. Thus, the properties of mutant strain T14V(PK455) associated the lectin activity with type 2 fimbriae, whereas those of strain T14AV provided little insight into the mechanism of lactose-sensitive adherence. In addition, the precise nature of the cell surface modification displayed by strain T14V(PK455) provides clear evidence for the existence of distinct and independent fimbriae on A. viscosus T14V.
Experimental infection of the New World owl monkey (Aotus trivirgatus) with hepatitis A virus
Authors: LeDuc J W , Lemon S M , Keenan C M , Graham R R , Marchwicki R H , Binn L N
Published: January 2020

Epidemiological studies have demonstrated the susceptibility of the owl monkey (Aotus trivirgatus) to hepatitis A virus, but have not shown an association between infection and histopathological or chemical evidence of liver disease. Therefore, 12 seronegative, colony-bred monkeys were inoculated intravenously with a fecal suspension containing either PA33 strain hepatitis A virus (a strain recovered from a naturally infected Aotus sp.) or HM-175 virus (recovered from a human). Viral antigen was detected by radioimmunoassay in the feces of six monkeys 6 to 17 days after inoculation with PA33 virus, and by 9 to 21 days serum aminotransferase activities were significantly elevated in each. Antibody to the virus developed in each monkey by 28 days after inoculation. Similar findings were noted in five of six monkeys inoculated with HM-175 virus, although the incubation period preceding aminotransferase elevations was somewhat longer (25 to 39 days). Liver biopsies obtained from the 11 infected monkeys demonstrated mild to moderate portal inflammation, as well as random areas of focal necrosis and inflammation extending outward from the portal region. These data confirm the susceptibility of Aotus sp. to hepatitis A virus and indicate that the infection of this primate provides a useful animal model of human hepatitis A.
Creutzfeldt-Jakob disease in mice: persistent viremia and preferential replication of virus in low-density lymphocytes
Authors: Kuroda Y , Gibbs C J , Amyx H L , Gajdusek D C
Published: January 2020

The mode of replication of the "unconventional virus" of Creutzfeldt-Jakob disease was studied in BALB/c mice infected intracerebrally. Virus was detected in the brain, spleen, lung, thymus, liver, kidney, and blood, but not in urine, at various time intervals after inoculation. The highest infectivity was present in the spleen from the second through the ninth weeks postinfection. Density gradient separation of spleen cells with colloidal silica (Percoll) revealed that the highest concentration of virus was present in blastoid cells from lower-density (1.05 to 1.07 g/ml) fractions. These results suggest that blastoid cells play an important role as the initial replication site of virus in the pathogenesis of Creutzfeldt-Jakob disease in mice.
Production of human interferon-gamma in serum-free medium
Authors: Tsujimoto M , Tarutani T , Ogawa K , Akashi K , Okubo Y , Higashi N
Published: January 2020

Interferon (IFN)-gamma was produced with a high yield in cultures of human peripheral mononuclear cells by combined stimulation with OK-432 and staphylococcal enterotoxin B. Human mononuclear cells cultured in serum-free medium produced several times as much IFN as those in RPMI-1640 medium containing 10% fetal bovine serum. A synergistic effect of OK-432 and staphylococcal enterotoxin B on the production of IFN-gamma was demonstrated. Ultrogel AcA54 column chromatography of crude IFN showed a single peak with an apparent molecular weight of 43,000. Our production system for human IFN-gamma offers a feasible approach to preparation of large quantities of purified IFN-gamma for structure studies, antibody production, and clinical applications.
Antibody and interferon act synergistically to inhibit enterovirus, adenovirus, and herpes simplex virus infection
Authors: Langford M P , Villarreal A L , Stanton G J
Published: January 2020

The possibility that interferon (IFN) and antibody could act together to reduce virus yields in infected cells was suggested by the simultaneous occurrence of IFN and antibody at infected sites. In the present in vitro studies, mixtures of IFNs and antibody acted synergistically to reduce virus yields in cultures infected with coxsackievirus A24, enterovirus 70, adenovirus, and herpes simplex virus. This synergistic reduction was observed in different cells and at different concentration of IFN and antibody. Although IFN and antibody acted synergistically against all viruses tested, the degree of synergism was dependent on the type of IFN or the virus. For example, IFN-beta and antibody was 10 to 200 times more effective than IFN-gamma and antibody against coxsackievirus A24, enterovirus 70, and adenovirus. A combination of antibody and IFN-gamma was three to five times more effective than IFN-beta and antibody against herpes simplex virus. In addition, we found that endogenously produced IFN-beta could act synergistically with antibody to coxsackievirus A24 to increase the overall antiviral effect by 10(5.0)-fold. No effect of endogenous IFN was observed in herpes simplex virus-infected cultures treated with antibody to herpes simplex virus. These studies indicate the potential importance of the synergistic effect of locally produced IFN and antibody in restricting virus early in the natural infectious process. They also suggest that combinations of IFNs and antibody may be more beneficial in the treatment of certain virus infections than IFN or antibody alone.
Cell-mediated immune response in Indian kala-azar and post-kala-azar dermal leishmaniasis
Authors: Haldar J P , Ghose S , Saha K C , Ghose A C
Published: January 2020

Cell-mediated immune (CMI) response in 16 Indian kala-azar (KA) and 12 post-kala-azar dermal leishmaniasis (PKADL) patients was studied in detail by in vitro lymphocyte transformation experiments and by in vivo skin testing. Peripheral blood lymphocytes of active KA patients failed to be stimulated by leishmania antigen. On the other hand, lymphocytes from a majority of the active KA patients could be stimulated by phytohemagglutinin. Active KA patients also failed to show delayed type hypersensitivity reaction to leishmanin, although 72% of them showed delayed type hypersensitivity to a purified protein derivative of tuberculin. Longitudinal studies indicated that antigen-specific CMI response usually appeared in treated KA patients after 12 to 20 weeks of antileishmanial drug therapy, although individual variations were noted. CMI response in PKADL patients was variable as about two-thirds of them showed positive sensitization to leishmania antigen in either in vivo or in vitro tests. Usually, patients with newly acquired PKADL exhibited better CMI response than those with chronic PKADL. However, lymphocytes from all of these patients could be stimulated normally by phytohemagglutinin. Results presented in this study show an impairment of CMI response in active KA which appears to be more specific to leishmania than generalized in nature. Moreover, restoration of specific T-cell responsiveness was aided by antileishmanial drug therapy which resulted in the reduction of antigenic load by parasite destruction and a concomitant decrease in circulating antibody levels, particularly that of the immunoglobulin G class. We suggest that the protection afforded by specific CMI response against Leishmania donovani infection may not be absolute and probably depends on other host-related factors leading to parasite destruction and patient recovery.
Entry of Shigella dysenteriae toxin into HeLa cells
Authors: Eiklid K , Olsnes S
Published: January 2020

The rate of shigella toxin entry into the cytosol of HeLa S3 cells was estimated from the toxin-induced reduction in protein synthesis. Whereas high toxin concentrations strongly reduced protein synthesis within 30 min, lower concentrations required longer times. The major part of the cell-bound toxin entered only after several hours. Toxin entered cells after incubation at 25 degrees C but not at 20 degrees C, although toxin binding was the same at the two temperatures. Increasing the KCl concentration to 0.2 M protected against toxin. The toxin entry was strongly reduced when the level of ATP in the cells was reduced by incubation with metabolic inhibitors. Lysosomotrophic agents such as NH4Cl and chloroquine had little or no protective effect, but the protonophores carbonyl cyanide p-trifluoromethoxyphenylhydrazone and carbonyl cyanide m-chlorophenylhydrazone and the ionophore monensin protected cells against the toxin. Cells were also protected when the pH was reduced to 6.4. The entry of shigella toxin is discussed in relation to that of other protein toxins with intracellular sites of action.
Diphtheria toxin does not enter resistant cells by receptor-mediated endocytosis
Authors: Morris R E , Saelinger C B
Published: January 2020

Diphtheria toxin (DT) and pseudomonas toxin are two distinct microbial toxins which inhibit protein synthesis in an identical manner, i.e., by the inactivation of cytoplasmic elongation factor 2. Although murine cells bind both toxins, they are 10,000-fold less sensitive to DT than to pseudomonas toxin. This suggests that the level of resistance resides at some event after binding. We have previously shown that pseudomonas toxin enters mouse LM fibroblasts by receptor-mediated endocytosis, a process in which ligand is internalized via specialized clathrin-coated pits and moves to the Golgi region and then to the lysosomes. Here, we visually follow the entry and trafficking of DT by resistant mouse fibroblasts. A biotinyl-toxin-avidin-gold system was used to visualize DT on the ultrastructural level. DT entered resistant cells through non-clathrin-coated regions of the plasma membrane and within 2.5 to 5 min was seen in lysosomes. Only rarely was DT seen in coated pits or in the Golgi region. Furthermore, the temperature dependence of internalization of 125I-labeled horseradish peroxidase and 125I-labeled DT by LM cells was similar. On the basis of these observations, we postulate that DT does not enter DT-resistant LM cells by receptor-mediated endocytosis and that receptor-mediated endocytosis is required for efficient expression of toxicity.
Immune rabbit sera do not recognize antigenic variants of caprine arthritis-encephalitis virus isolated during persistent infection
Authors: Anderson L W , Klevjer-Anderson P , McGuire T C
Published: January 2020

Isolates of caprine arthritis-encephalitis virus recovered 12 to 18 months after infection of goats were tested for neutralization by using rabbit antisera directed to the original inoculum virus. Only slight differences in neutralization kinetics between the long-term isolates and the original virus were detected, indicating that heterologous rabbit antisera do not detect antigenic variation of the neutralizing epitopes of caprine arthritis-encephalitis virus.
Surface localization of Pseudomonas aeruginosa outer membrane porin protein F by using monoclonal antibodies
Authors: Mutharia L M , Hancock R E
Published: January 2020

Hybridomas secreting highly specific monoclonal antibodies against porin protein F of Pseudomonas aeruginosa were isolated. These antibodies interacted with protein F in outer membranes isolated from strains representing the 17 serotypes of P. aeruginosa and from another 15 clinical isolates from patients with cystic fibrosis. The cell surface localization of antigenic sites on protein F was shown by indirect immunofluorescent techniques with these monoclonal antibodies. No fluorescence was observed on a protein F-deficient strain H283 of P. aeruginosa. Another monoclonal antibody specific for outer membrane lipoprotein H2 of P. aeruginosa showed no fluorescence on intact, wild-type bacterial cells, but was able to interact with a rough, LPS-deficient mutant.
Killing of Aspergillus spores depends on the anatomical source of the macrophage
Authors: Schaffner A , Douglas H , Braude A I , Davis C E
Published: January 2020

To resolve the controversy over the capacity of macrophages to kill or inhibit germination of Aspergillus spores, we compared this function in peritoneal and alveolar macrophages. Alveolar macrophages from rabbits killed 82 to 90% and completely digested 72 to 82% of spores of Aspergillus fumigatus in 30 h. In contrast, peritoneal macrophages could not even inhibit the germination of ingested spores; more than 85% transformed into mycelia within 24 h. Killing by alveolar macrophages was delayed for 3 to 6 h after phagocytosis and was independent of oxidative killing mechanisms and immune activation. The ability of alveolar macrophages to kill Aspergillus spores without modulation by T lymphocytes or the generation of oxygen intermediates points out that concepts built on studies of peritoneal macrophages may be misleading and underscores the importance of studying the role of macrophages in immunity with cells from the appropriate anatomical site.
Simple adult rabbit model for Campylobacter jejuni enteritis
Authors: Caldwell M B , Walker R I , Stewart S D , Rogers J E
Published: January 2020

We tested the usefulness of the Removable Intestinal Tie Adult Rabbit Diarrhea model to establish Campylobacter jejuni infection in rabbits. The procedure involved ligation of the cecum, placement of a slip knot at the terminal ileum, and injection of the test inoculum into the mid-small bowel. The ends of the slip knot were externalized, and the tie was released 4 h later. Fifty-five rabbits received C. jejuni, and 16 received uninoculated medium as controls. Daily rectal swabs were positive for 2 weeks in infected rabbits. The diarrheal attack rate was 64% in infected rabbits and 0% in controls. Diarrhea was characterized by loose, mucus-containing stools after an incubation period ranging from 24 h to 6 days. When blood was obtained daily for culture from 30 rabbits for 4 days post-challenge, bacteremia was present in 96.3% 24 h after challenge but diminished to 5 of 19 (26.3%) at 96 h. Death occurred in 53% of rabbits and was always preceded by diarrhea. No control animal died. Only 5 of 35 animals experiencing diarrhea recovered. An indirect whole-cell enzyme-linked immunosorbent assay was used to determine serum immunoglobulin G responses. Mean titers rose from 1:198 preoperatively to 1:9,087 on day 28. Necropsy on eight infected and two control animals showed inflammatory lesions with ulceration in 62.5% and goblet cell hyperplasia in 75% of infected rabbits. We conclude that the Removable Intestinal Tie Adult Rabbit Diarrhea procedure is a simple, effective method to establish C. jejuni infection which mimics human disease.