bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation of the L-phase variant from toxigenic Corynebacterium diphtheriae C7(beta)
Authors: Kanel C , Uchida T , Yoneda M
Published: January 2020

The L-phase variant was isolated from lysogenic strain C7(beta) of Corynebacterium diphtheriae by the penicillin disk tecnnique on an agar medium containing 3.7% brain heart infusion, 3% NaCl, 1.25% Grycine, 1% Noble agar, and 10% horse serum. The L-phase formed a "fried egg" colony; it was resistant to antibiotics that inhibit biosynthesis of bacterial cell walls but was susceptible to antibiotics that act on the protein-synthesizing system. After several transfers of the L-phase initially isolated, the L-phase of strain C7(beta) became stable, forming a typical L-phase colony on the agar even without penicillin. The L-phase variant retained lysogenicity and toxigenicity. The toxin production by this L-phase variant was, like that by the bacterial phase, inhibited by excess iron.
Degradation of the polysaccharide component of gonococcal lipopolysaccharide by gonococcal and meningococcal sonic extracts
Authors: Apicella M A , Breen J F , Gagliardi N C
Published: January 2020

An extract made from the supernatant of Neisseria gonorrhoeae Gc2 strain 1291 degraded the Gc2 polysaccharide antigen. Chemical analysis of this polysaccharide indicated it contains glucose, galactose, glucosamine, galactosamine, glucosamine-6-phosphate, heptose, 2-keto-3-deoxyotonate, and ethanolamine and is the polysaccharide component of gonococcal lipopolysaccharide. Degradation of the polysaccharide by sonic extracts resulted either in complete loss of antigenicity and immunogenicity or in partial degradation to subunits that could inhibit the Gc2-specific hemagglutination inhibition. The factors responsible for degradation were destroyed by heating at 100 degrees C for 5 min or by Pronase digestion, but were unaffected by ribonuclease, deoxyribonuclease, Mg2+, Ca2+, or ethylenediaminetetraacetic acid. The process was pH dependent, with optimal activity occurring at pH 7. Sonic extract supernatants from group B and C meningococcal strains contained degrading properties, whereas similar extracts produced from Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus pneumoniae type II failed to degrade the Gc2 polysaccharide.
Loss on serial passage of rhesus monkey kidney cells of proteolytic activity required for Sendai virus activation
Authors: Silver S M , Scheid A , Choppin P W
Published: January 2020

Primary and secondary cultures of rhesus monkey kidney cells supported multiple-cycle replication of Sendai virus, but later passages lost this ability, and this was reflected in decreased plaque formation. Multiple-cycle replication also did not occur in LLC-MK2 cells, a continuous line of RMK cells. Failure of replication in serially passed cells was correlated with a decrease in proteolytic cleavage of a viral surface glycoprotein (Fo), and the ability of cells to support multiple-cycle replication and plaque formation could be restored by the addition of trypsin (0.3 microgram/ml) to the overlay medium. The use of wild-type virus, which requires trypsin, and protease activation mutants that require chymotrypsin or elastase for activation has provided evidence that the activating protease supplied by primary or secondary cells has trypsin-like activity. Inactive virus, with uncleaved Fo glycoprotein, absorbed to primary or secondary cells but did not infect them, even though such cells possess the enzyme that is capable of cleaving the Fo glycoprotein of virus synthesized in these cells. The inability of these cells to activate adsorbed virus indicates that the activating protease that they possess is inacessible to adsorbed virus, although it can act on the Fo glycoprotein during virus maturation in these cells. These data provide a biochemical explanation for the failure of later passages of a cell strain or a continuous cell line to support the replication of a paramyxovirus.
Effect of Mycobacterium tuberculosis BCG infection on the resistance of mice to ectromelia virus infection: participation of interferon in enhanced resistance
Authors: Suenaga T , Okuyama T , Yoshida I , Azuma M
Published: January 2020

Mice infected with Mycobacterium tuberculosis BCG were more resistant than normal mice to ectromelia virus infection. It is suggested that enhanced interferon production in peritoneal exudate cells and spleen cells of BCG-infected mice plays an important role in this resistance.
Enteropathogenicity of Escherichia coli isolated from hamsters (Mesocricetus auratus) with hamster enteritis
Authors: Frisk C S , Wagner J E , Owens D R
Published: January 2020

Escherichia coli isolated from ilea of hamsters with hamster enteritis were tested for enteropathogenicity in intestinal loops prepared in both adult and weanling hamsters. E. coli isolated from hamsters with hamster enteritis caused dilatation of loops in weanling hamsters but not in adult hamsters.
Effects of age and ambient temperature on the responses of infant mice to heat-stable enterotoxin of Escherichia coli: assay modifications
Authors: Moon H W , Fung P Y , Whipp S C , Isaacson R E
Published: January 2020

The response of infant mice to heat-stable enterotoxin from Escherichia coli was affected by the age of the mice (2, 4, 6, and 8 days) and by the ambient temperature (25, 30, and 37 degrees C) after exposure to the enterotoxin. The younger mice and/or mice held at lower temperatures tended to accumulate intestinal fluid (high gut weight/body weight ratios), but older mice and/or mice held at higher temperatures tended to respond with diarrhea and low gut weight/body weight ratios. The standard infant mouse assay forheat-stable E. coli enterotoxin can be simplified, without loss of sensitivity or reliability, by holding the mice at 37 degrees C after exposure and using diarrhea as the index of response. Diarrhea can be detected easily by incorporating dye in the inocula and (at the end of the assay) checking for dye mixed with feces on the rear quarters of the mice or on a sheet of white paper placed under them during incubation.
Effect of growth environment on Pseudomonas aeruginosa killing by rabbit polymorphonuclear leudocytes and cationic proteins
Authors: Finch J E , Brown M R
Published: January 2020

Pseudomonas aeruginosa grown in a chemostat under carbon- and magnesium-limited conditions showed varying resistance to killing by rabbit peritoneal exudate polymorphonuclear leukocytes. Slow-growing (D = 0.05 h-1), magnesium-limited cells were significantly more resistant to the lethal effects of the phagocytes than were fast-growing magnesium-limited cells and carbon-limited cells (D = 0.05 h-1 and D = 0.5 h-1, respectively). The resistance of magnesium-limited cells to killing by cationic proteins isolated from the leukocytes was shown to be growth-rate dependent, the slowest-growing (D = 0.05 h-1) cells being the most resistant. Carbon-limited cells were sensitive to killing by the cationic proteins at all growth rates tested. Antisera raised in rabbits to all types of cells and commercial anti-Pseudomonas serum rapidly agglutinated magnesium-limited cells but failed to agglutinate carbon-limited cells. There was some indication that slow-growing (D = 0.05 h-1), magnesium-limited cells agglutinated most readily with both types of antisera. No difference was detected in the mouse toxicity of heat-killed cells grown under the various conditions.
Immune response to persistent mycobacterial infection in mice
Authors: Collins F M , Morrison N E , Montalbine V
Published: January 2020

Mycobacterium marinum has been recommended as a possible model of M. leprae for use in laboratory studies of antileprosy immunity. M. marinum introduced into the footpads of normal mice underwent a steady decline in viability, with less than 1% survival after a 30-day period. Small numbers of viable bacilli were recovered from the footpads of these mice up to 12 months later. Similarly, mice infected with M. simiae exhibited bacterial populations that persisted for up to 18 months with little change in viability. Injection of M. simiae into the footpads was followed by an extensive redistribution of the organisms in the tissues. Eventally, bacterial counts for footpads and draining lymph nodes stabilized, with small numbers of bacilli still present in the footpads 18 months later. Persistent growth, with little sign of any immune response, was also observed in mice infected with several strains of M. avium, as well as with one strain of M. intracellulare. Other strains of M. intracellulare, as well as M. vaccae and M. nonchromogenicum, failed to establish persistent infections in normal mice, regardless of whether they were introduced by an intravenous or subcutaneous (footpad) route. The relevance of these findings is discussed in relation to antileprosy immunity in experimental animals and in humans.
Activation of Alveolar Macrophages Exposed to Lavage-Procured Immunoglobulin G Obtained from Normal Rabbit Lungs
Authors: Ando Masayuki , Suga Moritaka , Shima Kiyoshi , Sugimoto Mineharu , Tokuomi Haruhiko
Published: January 2020

Pulmonary washings from rabbits were freed of cells and added to the monolayers of homologous alveolar macrophages (AM). At 1 h after incubation with the pulmonary washings, many more cells adhered to glass, spread out, and showed enhanced Nitro Blue Tetrazolium reduction. The maximal effect of the pulmonary washings on AM activation was obtained 12 h after incubation. The AM activated by the pulmonary washings showed a higher capacity to inhibit the growth of intracellular BCG, and that capacity was correlated with the intensity of Nitro Blue Tetrazolium reduction by the AM. Gel filtration of the pulmonary washings through Sepharose 4B yielded five fractions. The factor that activated the AM functions was in fraction 4. When the immunoglobulin G in the fraction was removed by an immunoadsorbent column, AM activity was abolished. The effect of the immunoglobulin G was dose dependent, and minimal responses to 10
6
cells per ml were obtained at a protein concentration of 20 μg/ml. Lymphokines had no effect on AM activation with respect to the morphological alterations and Nitro Blue Tetrazolium reduction during the 24-h observation time. In summary, AM from normal rabbits were soon activated markedly by lavage-procured immunoglobulin G, but not by lymphokines.
Clindamycin-induced enterocolitis in hamsters as a model of pseudomembranous colitis in patients
Authors: Chang T W , Bartlett J G , Gorbach S L , Onderdonk A B
Published: January 2020

Stools from a patient with antibiotic-associated colitis and cecal contents from a hamster with clindamycin-induced enterocolitis were compared in a cytotoxicity assay to determine common properties. Both specimens produced actinomorphic changes in human amnion cells at 10(-7) dilutions. The toxin was acid labile, heat labile, nonether extractable, non-dialyzable, and produced maximum activity at 60% with ammonium sulfate precipitation. Cytotoxicity was neutralized with clostridial antitoxin but not with equine serum. Clostridium difficile was recovered in high concentrations in specimens from both the hamster and patients. The supernatants of these C. difficile strains produced cytoxic effects which were also neutralized by clostridial antitoxins. These results indicate that clindamycin-induced enterocolitis in hamsters is a model of human disease and implicate toxin-producing clostridia as responsible agents.
Relationship of method of administration to respiratory virulence of Klebsiella pneumoniae for mice and squirrel monkeys
Authors: Berendt R F
Published: January 2020

Klebsiella pneumoniae given by aerosol was significantly less virulent in mice and monkeys than when given by intranasal (mice) or intratracheal (monkeys) instillation.
Detection of the Rocky Mountain spotted fever agent, Rickettsia rickettsii, in dead ticks, Dermacentor andersoni
Authors: Kurz J , Burgdorfer W
Published: January 2020

Rickettsia rickettsii remained viable and retained chromophilic properties for not more than 24 h after Dermacentor andersoni were killed by freezing. Antigenic reactivity was detected for at least 71 days by direct immunofluorescence. However, rickettsiae in ticks suffocated with mineral oil remained pathogenic for at least 14 days. Accordingly, ticks removed from a host by mineral oil or dying from desiccation in transit are still suitable for rickettsial examination.
Interaction of glucosyltransferase with the cell surface of Streptococcus mutans
Authors: Kuramitsu H K , Ingersoll L
Published: January 2020

The partially purified glucosyltransferase (GTF) fraction synthesizing primarily water-insoluble glucans, GTF-A, and the homogeneous fraction synthesizing water-soluble glucans, GTF-B, were utilized to assess the binding of GTF activity to the cell surface of Streptococcus mutans GS-5. Growth of the cells in either Todd-Hewitt broth or a chemically defined medium did not appear to affect the ability of the cells to bind either enzyme fraction. Heat inactivation of the cells did not singificantly reduce the interaction of the enzymes with the cells. Cell surface glucan molecules appear to be involved in GTF binding to the cells because: (i) dextranase or alpha-1,3-glucanase treatment of the cells markedly reduced enzyme binding; (ii) the inclusion of soluble dextrans in the binding assays reduced both GTF-A and GTF-B binding to the cells; and (iii) pretreatment of the cells or the GTF-B fraction with soluble dextrans before binding significantly reduced enzyme binding to the cells. In addition, enzyme binding appears to require a cell surface protein component because Pronase, but not trypsin, treatment of cells reduced enzyme binding. Furthermore, the removal of a portion of the cell surface GTF-glucan complex with 3 N NaCl appears to provide additional binding sites for the enzymes. These results are interpreted in terms of the mechanism of the conversion of extracellular GTF to the cell-associated form.
Water-soluble adjuvant obtained from Bacterionema matruchotii
Authors: Nitta T , Okumura S , Tanabe M J , Nakano M
Published: January 2020

The adjuvant effect of a butanol-extracted water-soluble adjuvant (bu-WSA) obtained from Bacterionemia matruchotii, a gram-positive oral bacteria, was studied on the antibody response at the plaque-forming cell (PFC) level in murine spleens. Intraperitoneal injection of Bu-WSA caused significant increase in direct PFC numbers in spleens 1 to 3 days after the antigenic stimulation with sheep erythrocytes (SRBC). Injection of 100 to 800 microgram of Bu-WSA was effective, and 400 microgram of Bu-WSA seemed to be the optimum for induction of the adjuvant effect. The adjuvant effect was strongest when Bu-WSA was injected at the same time as the SRBC, but some effect was still observed when Bu-WSA was injected 7 days before or 1 day after the immunization. The adjuvant effect of Bu-WSA was greatest at high dose of antigen. The mice injected with Bu-WSA at the time of priming SRBC and then immunized with trinitrophenylated SRBC showed greater anti-trinitrophenyl PFC response than controls without the injection of Bu-WSA. These findings suggest that a part of the adjuvant effect of Bu-WSA depends on thymic cell function and another part does not.
Mechanisms of lipopolysaccharide-initiated rabbit platelet responses: alternative complement pathway dependence of the lytic response
Authors: Morrison D C , Kline L F , Oades Z G , Henson P M
Published: January 2020

Experiments were performed to examine the relationship of endotoxin-initiated complement activation and rabbit platelet lysis. The results of these experiments supported the concept that activation of the alternative pathway is required for endotoxin-initiated complement-dependent rabbit platelet lysis. Our data demonstrated that preparations of endotoxin or isolated lipid A, which activate selectively the classical pathway, are incapable of initiating platelet lysis. Essentially equivalent results were obtained in citrated or heparinized plasma, although the latter anticoagulated plasma appeared to be more efficient in supporting lysis. Additional data support the concept that natural antibody to either the polysaccharide or the lipid A region of the lipopolysaccharide, which might be present in rabbit plasma, probably did not play a prominent role in the complement-mediated lytic response.
Replication of dengue and junin viruses in cultured rabbit and human endothelial cells
Authors: Andrews B S , Theofilopoulos A N , Peters C J , Loskutoff D J , Brandt W E , Dixon F J
Published: January 2020

The flavivirus dengue and the arenavirus Junin are both associated with a hemorrhagic shock syndrome in man. We have demonstrated the replication of these viruses in vitro in both rabbit and human endothelial cells by viral titers and immunofluorescent antibody studies. Rabbit endothelium established in continuous culture was derived from vena cava, while human cells in primary culture were derived from umbilical veins. In rabbit endothelium, dengue-2 virus passaged through monkey kidney monolayer cells (LLC-MK2) or human lymphoblastoid cells (raji) produced significantly more virus than the seed obtained from suckling mouse brain (MB). Inoculation of actively dividing, subconfluent human endothelial cells with the LLC-MK2 degue virus produced higher viral titers than inoculation of confluent cells. The appearance of Junin virus was delayed beyond that of dengue virus in rabbit endothelial cells although equivalent titers of virus were produced. In human cells, Junin virus was less productive than dengue virus and produced characteristic cycles of virus release. This is the first direct evidence for replication of human hemorrhagic fever viruses in endothelial cells.
Protective effect of glucan against systemic Staphylococcus aureus septicemia in normal and leukemic mice
Authors: Di Luzio N R , Williams D L
Published: January 2020

The reticuloendothelial stimulant glucan, a beta-1,3-polyglucose component of the cell wall of Saccharomyces cerevisiae, was evaluated for its ability to modify Staphylococcus aureus-induced lethality in normal and leukemic mice. In normal mice the intravenous injection of glucan (0.45 mg per mouse) 7 and 4 days prior to intravenous challenge with S. aureus (1.0 x 10(9)) resulted in a significantly increased survival. Histological examination of the kidneys revealed that glucan significantly inhibited renal necrosis associated with systemic staphylococcal diseases. Further studies indicated that glucan administration not only enhanced survival of leukemic mice, but also increased survival of leukemic mice with experimentally induced staphylococcal speticemia. These data denote that glucan enhances nonspecific resistance to S. aureus sepsis, promotes survival during leukemic episodes, and increases survival time of leukemic mice with experimentally induced staphylococcal infection.
Serotyping of Chlamydia: antibodies to lymphogranuloma venereum strains compared by microimmunofluorescence and neutralization tests
Authors: Banks J , Schachter J
Published: January 2020

The microimmunofluorescence test with hyperimmune rooster sera against lymphogranuloma venereum strains gave the same serotype patterns obtained in the standard mouse serum system. Results in a plaque reduction test appeared similar when only 3 prototype strains were tested, but differed when a battery of 11 strains were tested.
Lactate dehydrogenase mutants of Streptococcus mutans: isolation and preliminary characterization
Authors: Hillman J D
Published: January 2020

Mutants of Streptococcus mutans were isolated which lack the enzyme activity L (+)-lactate dehydrogenase. Reversion studies indicate that the genetic defects are in the structural gene for the enzyme. The mutants produce less titratable acid from glucose, adhere better to hydroxyapatite, and accumulate more plaque when grown in the presence of sucrose than does the parent strain. These findings suggest a possible use for the mutants as effector strains in the replacement therapy of dental caries.
Demonstration of three different subtypes of adenovirus type 7 by DNA restriction site mapping
Authors: Wadell G , Varsanyi T M
Published: January 2020

Restriction site mapping of the genomes of eight different isolates of adenovirus serotype 7 (Ad7) has been performed with six different restriction endonucleases. In this analysis, 37 different restriction sites were localized. Three distinctly different cleavage patterns of the genomes of the Ad7 strains were observed. These strains could not be distinguished by serological techniques. The following three subtypes were defined on the basis of their restriction site patterns: the Ad7 prototype, represented by strain Gomen originally isolated from a case of pharyngitis; subtype Ad7a, represented by the Ad7 vaccine strain and strains isolated from undifferentiated respiratory disease and from a healthy carrier; and a third subtype of Ad7, represented by three strains which were isolated from Swedish patients, all having pronounced clinical symptoms indicating severe systemic infection. A comparison of the restriction site maps of the protype of Ad3 and the three subtypes of Ad7 indicated greater differences in the position of restriction sites between strains of Ad7 than between strains of the two serotypes. This technique is consequently recommended to obtain a more precise definition of distinct entities of viruses.
Characterization of glucosyltransferase-deficient, plasmid-containing mutants of Streptococcus mutans LM-7
Authors: Donkersloot J A , Flatow U , Gibson E , Chassy B M
Published: January 2020

The possibility that glucosyltransferase (GT)-mediated insoluble-glucan synthesis from sucrose is controlled by the 3-megadalton plasmid pAM7 in Streptococcus mutans LM-7 has been examined. A low-sucrose agar medium was developed to readily detect and quantitate presumptive GT-negative mutants. Such mutants were isolated from Todd-Hewitt broth cultures grown either with or without sodium dodecyl sulfate (10 microgram/ml) or acriflavine (0.5 microgram/ml) at frequencies ranging from about 0.01 to 1%. Independently isolated mutants had the following characteristics: (i) cells were virtually devoid of cell-associated GT and did not aggregate upon addition of sucrose; (ii) cell-free culture fluids synthesized 10X less insoluble glucan than those of the parent; and (iii) cultures grown with sucrose did not form adherent deposits on the wall of the culture tube, as is typical of S. mutans. Both parent and mutants formed relatively little soluble glucan in 1-h assays. Three independently isolated mutants and the parent were found to contain similar amounts of plasmid DNA. Analysis by sucrose density gradient centrifugation and agarose gel electrophoresis did not reveal a size difference between the plasmids from parent and mutants. These results show that (i) S. mutans LM-7 generates GT-deficient mutants at relatively high frequency that still contain a 3-megadalton plasmid; (ii) both cell-associated and extracellular GT levels are depressed in the mutants, which suggests that these activities are directly or indirectly controlled by the same gene or by genes that segregate as a unit.
Long-term fecal excretion and resistance induced in mice infected with Yersinia enterocolitica
Authors: Ricciardi I D , Pearson A D , Suckling W G , Klein C
Published: January 2020

European isolates of Yersinia enterocolitica serotypes O3 and O9 were shown to infect but not kill mice, which became fecal excreters for up to 135 days. The mice challenged with 500 50% lethal doses of the virulent WA strain of Y. enterocolitica serotype O8 survived, and some excreted the virulent strain. This rodent model may be of value in assessing the ecological significance of rodents in the maintenance of Y. enterocolitica.
Growth of salmonellae in orally infected germfree mice
Authors: Collins F M , Carter P B
Published: January 2020

Germfree mice were infected intragastrically, intravenously, or intraperitoneally with 10(3) to 10(9) viable Salmonella typhi Ty2, S. gallinarum 9240, or S. enteritidis 5694. The 50% lethal doses were compared with those for conventionally raised mice. Substantial growth of the salmonellae occurred in the intestinal tract of the germfree mice but, despite the presence of more than 10(9) viable S. typhi or S. gallinarum in the lumen, the liver and spleen cultures remained Salmonella-free, and all of the mice survived the oral challenge. The ileal and cecal Peyer's patches and the mesenteric lymph nodes of these mice contained 10(3) to 10(4) viable salmonellae within 24 h of introduction of the inoculum into the stomach. Despite this local involvement, the infection did not spread systemically even when host resistance was reduced by means of sublethal, whole-body gamma irradiation before oral challenge. Germfree mice infected orally with as few as 10 mouse-virulent S. enteritidis quickly developed severe diarrhea and died within 5 to 8 days as a result of a spreading systemic disease.
Characterization of an Escherichia coli plasmid encoding for synthesis of heat-labile toxin: molecular cloning of the toxin determinant
Authors: So M , Dallas W S , Falkow S
Published: January 2020

P307 is a plasmid isolated from a strain of Escherichia coli that was responsible for an outbreak of diarrheal disease in piglets. This 60 X 10(6)-dalton plasmid was subsequently shown to encode for the synthesis of a heat-labile toxin (LT). Using recombinant DNA technology, we isolated a 7.8 X 10(6)-dalton DNA fragment that contains the LT gene(s). This fragment was generated using an EcoRI partial digestion of P307 DNA, and the fragment was joined to a small multicopy plasmid, RSF2124. E. coli strains harboring the chimeric plasmid produced greater amounts of LT than did the same strains containing P307. The LT genes were also isolated on a 5.8 X 10(6)-dalton DNA fragment made by BamHI digestion, and we identified an EcoRI recognition sequence that is located in a position essential for LT synthesis.
Mechanisms of immunity in typhus infection: some characteristics of Rickettsia mooseri infection of guinea pigs
Authors: Murphy J R , Wisseman C L , Fiset P
Published: January 2020

Rickettsia mooseri infection has been studied in syngeneic guinea pigs inoculated intradermally with the objective of developing a model for the study of immune mechanisms. Characterization of infection included the following: a study of replication, dissemination, and clearance of rickettsiae; measurement of the antibody response with different rickettsial antigens and tests; and attempts to measure the cell-mediated immune response using the correlate of delayed-type hypersensitivity skin reactions. Following intradermal inoculation, rickettsiae replicate locally and then spread to the draining lymph nodes and subsequently cause systemic infection. Spread to draining lymph nodes occurred before the appearance of circulating antibody, whereas systemic infection occurred afterwards. Two distinct patterns of acquired resistance developed. The first was marked by a cessation of rickettsial growth within a given organ and the second by a clearance of rickettsiae. The duration of each of these phases differed markedly from one organ to another. Delayed-type hypersensitivity was not demonstrated by skin testing.
Hepatitis B surface antigen-specific cell-mediated immune responses in human chronic hepatitis B surface antigen carriers
Authors: Beutner K R , Tiku M L , Ogra P L
Published: January 2020

The presence of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs), hepatitis B e antigen (HBeAg) and antibody (anti-HBe), the nature of T-cell function, and specific cell-mediated immunity to HBsAg were determined and evaluated serially in groups of subjects with chronic HBsAg carrier states and in seronegative controls. The techniques of in vitro lymphocyte transformation, spontaneous rosette formation, radioimmunoassay, reverse passive hemagglutination, passive hemagglutination, rheophoresis, and liver function tests were employed for these studies. For the lymphocyte transformation assay, multiple concentrations of phytohemagglutinin and purified HBsAg were used as stimulants. Cell-mediated immunity to HBsAg was detectable in 50% of the chronic HBsAg carriers (responders) at one or more concentrations of HBsAg. The remaining carriers (nonresponders) and controls failed to manifest HBsAg-specific lymphocyte transformation activity. The profile of the responders was characterized by elevated serum glutamic pyruvic transaminase levels, the presence of anti-HBe, high HBsAg titers, and the conspicuous absence of HBeAg in the serum. The nonresponders were characterized by normal serum glutamic pyruvic transaminase levels, the presence of HBeAg and anti-HBe, and lower HBsAg titers. These observations demonstrate the presence of specific cell-mediated immunity to HBsAg in chronic HBsAg carriers who manifest biochemical evidence of liver disease.
Antibody-mediated recovery from subcutaneous herpes simplex virus type 2 infection
Authors: Oakes J E , Rosemond-Hornbeak H
Published: January 2020

Young adult mice infected with 3 X 10(6) plaque-forming units of herpes simplex virus type 2 (HSV-2) died within 9 to 12 days after spread of the virus from the sites of infection to the spinal cord and brain. Administration of HSV-2-neutralizing antisera prepared in syngenic mice or in rabbits inhibited spread of the virus from the footpad of infected animals and prevented death. A single intraperitoneal inoculum of antiserum (virus-neutralizing titer of 1:128) was effective in protecting mice when the antiserum was given at 8 to 48 h, but not at 72 h, after virus inoculation. Immune sera absorbed with HSV-2-infected cells no longer protected mice from subcutaneous infection, whereas absorption with noninfected cells had no effect. Thus, HSV-2-specific antibodies appeared to be responsible for the protection observed. If the mice were given a sublethal dose of irradiation (390 rads) at 24 h before antibody transfer, protection was no longer obtained. This suggested that the mechanism of protection probably was not solely due to in vivo neutralization of virus, but required the participation of a radiosensitive component which has not yet been defined.
Some ultrastructural effects of persistent infections by the rickettsia Coxiella burnetii in mouse L cells and green monkey kidney (Vero) cells
Authors: Burton P R , Stueckemann J , Welsh R M , Paretsky D
Published: January 2020

Mouse fibroblasts (L-929) and Vero (green monkey kidney) cells were infected with the rickettsia Coxiella burnetti, and persistent infections developed and were studied over a 6- to 10-month period. Ultrastructural comparisons were made between the two infected cell types, and both were tested cytochemically for the presence of acid phosphatase, a marker enzyme of lysozymes. Rickettsiae were always observed within vacuoles, and some infected L cells showed flattened endoplasmic reticulum as compared with uninfected cells. Rickettsiae in Vero cells were most often seen in vacuoles containing whorls of membranes ("myelin configurations") which were also seen in uninfected cells. Rickettsiae in Vero cells were pleomorphic, with acid phosphatase reaction product in their periplasmic space. This suggests either rickettsial degradation by lysosomal enzymes which penetrated the cell envelope or a penetration after the rickettsiae were dead. Vacuoles of infected Vero cells showed much more reaction product than that in infected L cells, and most rickettsiae in L cells had a normal appearance and showed no reaction product in their periplasmic space.
Interaction of Inflammatory Cells and Oral Microorganisms VII. In Vitro Polymorphonuclear Responses to Viable Bacteria and to Subcellular Components of Avirulent and Virulent Strains of
Actinomyces viscosus
Authors: Taichman Norton S. , Hammond Benjamin F. , Tsai Chi-Cheng , Baehni Pierre C. , McArthur William P.
Published: January 2020

Both virulent (V) and avirulent (AV) strains of
Actinomyces viscosus
T14 are capable of colonizing the oral cavity of gnotobiotic rats, but only T14-V causes destructive periodontal disease. The basis for this difference in in vivo pathogenicity has not been adequately defined. In the present study we compared the capacities of T14-AV and T14-V to provoke in vitro extracellular release of lysosomal constituents from human polymorphonuclear leukocytes (PMNs). In serum-free cultures, viable T14-V but not T14-AV stimulated discharge of PMN lysosomes. The release response was correlated with PMN phagocytic activity; thus, PMNs readily ingested T14-V but not T14-AV. To explain these differences in PMN-bacteria interactions, subcellular fractions of T14-AV or T14-V were incubated with PMNs. A crude, insoluble sonic extract derived from T14-V caused PMN lysosome release, but a similar fraction from T14-AV was inactive. However, following extensive washing and treatment with deoxyribonuclease or sodium dodecyl sulfate, cell wall fractions of T14-AV stimulated lysosome release. These procedures apparently removed an extracellular polysaccharide slime which is synthesized by T14-AV but not by T14-V. There was a significant reduction in the capacities of viable T14-V or cell wall fractions of T14-V or T14-AV to provoke PMN lysosome release when these agents were preincubated with a slime material isolated from T14-AV. This inhibitory influence of slime was overcome by the addition of fresh or heated (56°C, 30 min) serum to the PMN-bacteria cultures. The data suggest a relationship between the abilities of the avirulent and virulent strains of
A. viscosus
T14 to act as periodontal pathogens in vivo and to serve as stimuli for PMN lysosome release in vitro.
Cyclophosphamide effects on murine cryptococcosis
Authors: Graybill J R , Mitchell L
Published: January 2020

BALB/c mice were given cyclophosphamide and challenged with Cryptococcus neoformans. Delayed-type hypersensitivity was transiently depressed, and survival was either unaffected or shortened by cyclophosphamide.
Some properties of beta-toxin produced by Clostridium perfringens type C
Authors: Sakurai J , Duncan C L
Published: January 2020

Purified beta-toxin from Clostridium perfringens type C was found to be a single polypeptide chain protein with a molecular weight of approximately 30,000. The toxin was heat labile, with 75% of its activity being inactivated by incubation at 50 degrees C for 5 min. Biological activity of the purified toxin was completely destroyed on exposure to trypsin for 30 min at 37 degrees C. The 50% lethal dose for mice was 1.87 microgram of purified toxin.
Experimental Murine Candidiasis: Pathological and Immune Responses in T-Lymphocyte-Depleted Mice
Authors: Giger Donald K. , Domer Judith E. , Moser Stephen A. , McQuitty J. T.
Published: January 2020

Mice depleted of T-lymphocytes by thymectomy and irradiation (TXB) and immunologically competent mice were compared for gross and histological pathology as well as immune responses after cutaneous and/or intravenous challenge with
Candida albicans
. In response to a first cutaneous inoculation with viable
Candida
, TXB, sham-operated (SXB), and unmanipulated (normal) mice, all developed lesions of comparable size, duration, and histopathology. When challenged a second time cutaneously, normal and SXB mice developed lesions which were greatly increased in size when compared with those produced by a first cutaneous infection, whereas TXB mice developed lesions comparable in size to those initiated by the first infection. Histologically, the first and second lesions in all animals were acute abscesses predominantly comprised of polymorphonuclear leukocytes. The larger second lesions in SXB and normal mice were accompanied by detectable circulating antibody and by delayed hypersensitivity. Neither circulating antibody nor delayed hypersensitivity were stimulated in the TXB mice. When challenged intravenously, all previously uninfected mice, regardless of T-cell status, were equally susceptible to
C. albicans.
Contrary to SXB or normal mice, however, TXB mice which had been infected cutaneously were not more resistant to a subsequent intravenous challenge as judged by 6-week survival. The results suggest that T-cells do not play a significant role in innate resistance of mice to systemic candidiasis, but that such cells are important in the development of acquired resistance.
Investigations on strain-specific and common antigen antihemagglutinin antibodies oriented to the influenza virus H3N2 strains A/Hong Kong/1/68 and A/Port Chalmers/1/73
Authors: Drescher J , Verhagen W
Published: January 2020

Antisera raised by vaccination of chickens with the H3N2 influenza virus strains A/Hong Kong/1/68 and A/Port/Chalmers/1/73 were found to contain common antigen antibody (CAA), combining with both viruses, and strain-specific antibody (SSA), combining with homologous virus only. The reaction of CAA with homologous and heterologous viruses and of SSA with homologous virus was investigated by means of equilibrium filtration. CAA was found to be antibody of higher quality than was SSA. The virus strains tested were found not to contain identical common antigenic determinants, and CAA and SSA competed for the same antigenic sites when allowed to react simultaneously with homologous virus. The kinetics of reaction of CAA and SSA with the corresponding viruses was tested by means of the photometric antibody concentration unit method. It was found that SSA and CAA of a given strain have the same specificity and that the reaction of CAA with heterologous virus is registered as heterologous antigen-antibody interaction. These findings suggest that SSA and CAA are antibodies of the same specificity but with differences in quality.
Role of hydrogen peroxide and peroxidase in the cytotoxicity of Trypanosoma dionisii by human granulocytes
Authors: Thorne K J , Svvennsen R J , Franks D
Published: January 2020

The mechanism of the cytotoxic reaction of leukocytes to Trypanosoma dionisii was investigated. Cytotoxicity was measured by release of [99mTc]pertechnetate from labeled protozoa. Both granulocytes and lymphocytes were found to be cytotoxic to antibody-coated T. dionisii. The reaction was inhibited by diethyldithiocarbamate and by potassium cyanide, both of which inhibit myeloperoxidase. Myeloperoxidase from azurophil granules was toxic to T. dionisii, provided that hydrogen peroxide was also present. Hydrogen peroxide formation was induced in granulocytes and, to a lesser extent, in lymphocytes by antibody-coated T. dionisii. Inhibition of this hydrogen peroxide formation by treatment of the effector cell surface with p-diazobenzenesulfonic acid inhibited cytotoxicity. It is therefore concluded that granulocytes, and probably also lymphocytes, kill T. dionisii with hydrogen peroxide by a peroxidase-mediated reaction. Although hydrogen peroxide and myeloperoxidase alone were also cytotoxic to the lymphoblastoid cell line CLA4, it seems unlikely that this is the cytotoxic mechanism for this process because these cells were unable to induce hydrogen peroxide formation.
Protective effect of early serum from mice after cytomegalovirus infection
Authors: Araullo-Cruz T P , Ho M , Armstrong J A
Published: January 2020

Serum obtained from mice 3 to 5 days after cytomegalovirus infection contained complement-requiring neutralizing antibody, which, when passively transferred, protected mice from lethal infection with the homologous virus. The active substance was largely heat-stable 7s immunoglobulin.
Peritoneal macrophage activation indicated by enhanced chemiluminescence
Authors: Schleupner C J , Glasgow L A
Published: January 2020

A number of studies have demonstrated the ability of various bacterial preparations, protozoa, and chemicals to activate macrophages and concomitantly to enhance host resistance to both tumors and infections. Recently, viral infections have been shown to have a similar effect upon macrophage function. To better define the metabolic state of activated macrophages, we have evaluated the ability of peritoneal cells (PC) from vaccinia virus- or murine cytomegalovirus-infected or Corynebacterium parvum-treated mice to emit chemiluminescence (CL) during phagocytosis of zymosan particles or yeasts. PC from C. parvum-treated mice (1,400 microgram intraperitoneally) emitted enhanced CL over controls on days 3, 6, 14, and 21 after treatment, thereby establishing the emission of CL as a correlate of metabolic activation. Previous evidence for activation of PC from vaccinia virus-infected mice (10(8) plaque-forming units) was confirmed by demonstration of enhanced levels of CL on days 3, 6, and 13 after murine infection. Likewise, PC from mice infected with murine cytomegalovirus (10(5) plaque-forming units) 3, 6, or 13 days previously demonstrated augmented levels of CL over controls. Opsonized virus particles (vaccinia virus or murine cytomegalovirus) failed to induce the emission of CL with PC from mice infected with the isologous virus. Our data further demonstrate the immunomodulationinduced by virus infections and suggest that the detection of CL is an easily quantitated correlate of macrophage activation which may be helpful in defining metabolic alterations induced during activation.
Characterization of group A streptococcal T-12 protein purified by ion-exchange column chromatography
Authors: Ludwicka A , Kłoczewiak M
Published: January 2020

The aim of the present study was to describe the physicochemical characteristics of streptococcal T antigen. T protein isolated from Streptococcus pyogenes type 12 (R53/1077, Colindale) and purified by ion-exchange column chromatography resulted in a preparation that was homogeneous when tested electrophoretically (in two systems, in presence and in absence of sodium dodecyl sulfate) and by gel filtration on Sephadex G-100. The purified T antigen was resistant to enzymatic degradation by trypsin and pepsin. It formed a single precipitin line with standard T-12 antiserum and was not contaminated with group A carbohydrate and M protein. The molecular weight of protein T, determined by means of polyacrylamide gel electrophoresis and calculated from its amino acid composition, was about 39,000. The molecular weight of this protein, determined by means of high-speed sedimentation equilibrium, ranged between 80,000 and 120,000. Glutamic and asparatic acids, lysine, alanine, and leucine were the predominant amino acids.
Nature and Specificity of Effector Cells in Cell-Mediated Cytolysis of Mouse Adenovirus-Infected Cells
Authors: Inada Toshiki , Uetake Hisao
Published: January 2020

The type of effector cells in immune spleen cells (ISC) responsible for cell-mediated cytolysis of mouse adenovirus-infected cells was characterized. When ISC were pretreated with anti-mouse thymocyte or anti-Thy1.2 serum and complement, their cytolytic activity assayed by the
51
Cr release test was completely abolished, whereas it was not significantly reduced either when ISC were pretreated with anti-mouse immunoglobulin serum and complement or after ISC were kept standing at 37°C for 2 h in a plastic dish to remove adherent cells. These data indicate that the effector cells in ISC are T cells. The release of nonspecific or specific soluble cytotoxic factor(s) from ISC upon contact with mouse adenovirus-infected cells was not demonstrated, but about 30 U of interferon activity per ml was detected. However, 10 times as many units of exogenous interferon or more showed no effect on
51
Cr release from target infected cells or on the inhibition of viral antigen synthesis in infected cells. Experiments with mouse cells of different major histocompatibility antigens indicated that the cytotoxicity of ISC is effective when sensitizer and target cells share all or part of the same
H-2
gene complex but not effective when they are of a different
H-2
gene complex.
Protective effects of a supernatant factor from Salmonella typhimurium on Salmonella typhimurium infection of inbred mice
Authors: Plant J , Glynn A A , Wilson B M
Published: January 2020

A supernatant factor prepared from 48-h cultures of Salmonella typhimurium has been used to immunize mice against subsequent challenge with normally lethal doses of S. typhimurium. The mouse strains used, C57BL and BALB/c, were sensitive to S. typhimurium with 50% lethal doses of less than 50 organisms. Two doses of supernatant factor, given intraperitoneally 20 days apart, protected mice against a subcutaneous challenge dose 10 days later of 100 50% lethal doses of S. typhimurium, resulting in 50 to 80% survival. The viable counts were reduced initially in organs of immunized mice compared with controls, and the multiplication of bacteria was delayed, although the final levels found in the organs would normally have been lethal. Protection obtained was specific for S. typhimurium in that no increased survival was shown after Salmonella enteritidis challenge of immunized mice. Although lipopolysaccharide was demonstrated in the supernatant factor, lipopolysaccharide alone did not protect challenged mice. Supernatant factor produced delayed-type hypersensitivity reactions in mice sensitized with nonlethal doses of Salmonella. The nature of the active factor, found to be partially protein, has yet to be elucidated.
DNA release as a direct measure of microbial killing by phagocytes
Authors: Friedlander A M
Published: January 2020

A new assay for the precise measurement of microbial killing by leukocytes is presented. The method assumes that release of radioactively labeled DNA from the microbe is direct evidence of cell death. Human peripheral blood leukocytes incubated with [14C]thymidine-labeled Salmonella typhimurium released 32 to 59% of the radioactivity after 4 h and 63 to 75% after 18 h. Inactivated leukocytes released less than 5% of the radioactivity. None of the released radioactivity is retained within the leukocyte, and 60% remains precipitable with trichloroacetic acid. Leukocytes released substantial radioactivity from labeled Escherichia coli but only a slight amount from staphylococci. Mouse peritoneal macrophages were also shown to release radioactivity from Salmonella. The DNA release assay avoids the errors inherent in prior killing methods which measure viability by growth inhibition. It is rapid, reproducible, and highly specific.
Detection of antibodies to Mycoplasma pulmonis by an enzyme-linked immunosorbent assay
Authors: Horowitz S A , Cassell G H
Published: January 2020

The enzyme-linked immunosorbent assay, which entails the use of antigen-coated tubes and enzyme-labeled anti-immunoglobulins, was applied for the detection of antibodies against Mycoplasma pulmonis in mice. A lysate of M. pulmonis was used as the antigen, and anti-mycoplasmal antibodies of the different immunoglobulin classes were detected by class-specific anti-immunoglobulin labeled with alkaline phosphatase. The optimal conditions for the test were determined, the specificity was evaluated, and the assay was compared with other procedures for detection of mycoplasmal infection. The enzyme-linked immunosorbent assay was found to be a specific, highly sensitive, and reliable procedure for detecting anti-mycoplasmal antibodies in mice.
Genetic separation of serum opacity factor from M protein of group A streptococci
Authors: Cleary P P
Published: January 2020

Mutagenized cultures of three strains of group A streptococci which were M positive and produced the extracellular serum opacity factor (OF) were screened for mutants which failed to exhibit OF activity on serum agar plates. All cell fractions from three mutants studied in detail, including culture supernatants, protoplast membranes, and cytoplasmic fractions, were completely devoid of activity. Two OF- isolates also lacked OF antigen, whereas the third continued to produce cross-reacting antigen. All three mutants were resistant to phagocytosis and yielded acid-extractable M antigen, indicating that the M protein of each strain was unaltered by the mutations. The separation of the OF+ and M+ phenotypes by mutation establishes that genes which code for the M protein and OF are distinct; therefore, the activities and antigenic determinants of each must be associated with separate, distinct protein molecules.