bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotype-Nonspecific Protection Induced by Ribonucleic Acid Isolated from the Ribosomal Vaccine of
Pseudomonas aeruginosa
Authors: Gonggrijp Rinske , Mullers Wil J. H. A. , van Boven C. P. A.
Published: January 2020

A ribosomal vaccine of
Pseudomonas aeruginosa
and a vaccine containing purified lipopolysaccharide (LPS) were compared with respect to their capacity to protect mice against a lethal challenge with
P. aeruginosa.
The route of vaccination appeared to be important for the protective activity of the ribosomal vaccine. Optimal protection was measured if both the immunizing and the challenge injection were given intraperitoneally. The ribosomal vaccine protected mice as early as 1 day after vaccination, and the protection lasted at least 6 days. LPS-specific antibodies were detectable 6 but not 2 days after vaccination. The ribosomal vaccine protected mice also against a heterologous serotype of
Pseudomonas.
Injection of purified LPS did not protect mice earlier than at day 3, and the protection induced by LPS was serotype specific. Ribonucleic acid (RNA) isolated from the ribosomal vaccine had the same protective properties as the ribosomes. RNA induced serotype-nonspecific protection as quickly as 1 day after injection, and the protection lasted at least 6 days. However, the capacity to induce antibodies to LPS was lost or reduced. It is concluded that the serotype-nonspecific protection induced by RNA and the serotype-specific protection induced by LPS are due to different mechanisms. Experiments with combined vaccines containing RNA and LPS demonstrated that the addition of RNA to LPS resulted in a slight increase in LPS-specific antibodies. The data presented indicate that both the serotype-specific protection induced by LPS and the serotype-nonspecific protection induced by RNA contribute to the protective activity of the ribosomal vaccine.
Murine cytomegalovirus infection: hematological, morphological, and functional study of lymphoid cells
Authors: Cheung K S , Li J K , Falletta J M , Wagner J L , Lang D J
Published: January 2020

Mice were studied for 3 to 4 months after murine cytomegalovirus (MCMV) infection. Serial hematological parameters were evaluated. It was found that MCMV infection of mice were accompanied by the appearance of many atypical lymphocytes similar to those seen in association with the hematological features of mononucleosis associated with human CMV infection. Certain functions of splenocytes were studied in infected and uninfected animals during the 4 months after MCMV infection. Three periods were identifiable by the functional response of splenocytes during the course of MCMV infection. The initial phase was characterized by an elevated response of splenocytes to a T cell mitogen and a B cell mitogen (phytohemagglutinin and lipopolysaccharide, respectively). The intermediate phase was marked by productive virus replication in the salivary gland, injury to lymphoid elements, a depressed response of splenocytes to mitogens (phytohemagglutinin and lipopolysaccharide), and decreased humoral splenocytes to phytohemagglutinin stimulation was again increased, and a nonproductive latent infection was established. Study by scanning electron microscopy of splenocytes during the course of infection revealed morphological changes which were correlated with functional alterations.
Antigenic and immunogenic properties of defined physical forms of tick-borne encephalitis virus structural proteins
Authors: Heinz F X , Tuma W , Kunz C
Published: January 2020

Polymeric, delipidated glycoprotein complexes of defined size and composition were prepared from tick-borne encephalitis virus by solubilization with Triton X-100 or cetyltrimethylammonium bromide, followed by centrifugation into detergent-free sucrose density gradients. The antigenic reactivities and immunogenicities of these complexes were compared with those of complete inactivated virus. These glycoprotein preparations induced hemagglutination-inhibiting and neutralizing antibodies which proved to be protective in passive mouse protection tests and monospecifically reacted only with the viral envelope and not with the internal core. In a competitive radioimmunoassay the glycoprotein complexes revealed about 10-fold higher antigenicity than whole virus when tested at equal protein concentrations. The important implications of these results with respect to antigen quantification in vaccines are discussed. As shown in the mouse challenge potency test, glycoprotein complexes prepared after Triton X-100 solubilization actively protected mice almost as well as did complete inactivated virus at the same protein concentration, whereas those prepared after cetyltrimethylammonium bromide solubilization had a somewhat lower protective activity per microgram of protein.
Polymyxin B Inactivation of Lipopolysaccharide in Vaccines of Gram-Negative Bacteria
Authors: Cooperstock Michael , Riegle Linda
Published: January 2020

Endotoxin activity in suspensions of
Bordetella pertussis, Escherichia coli, Haemophilus influenzae
, and
Pseudomonas aeruginosa
was often markedly decreased by polymyxin B. Polymyxin B treatment may be a means to reduce inflammatory reactivity of lipopolysaccharide in vaccines of gram-negative bacteria.
Serological Investigation of the possibility of congenital transmission of papovavirus JC
Authors: Daniel R , Shah K , Madden D , Stagno S
Published: January 2020

In an examination of paired sera from pregnant women, 9 of 57 women who had JC virus antibodies in their first specimens exhibited virus reactivation, as judged by a fourfold or greater rise in JC virus hemagglutination-inhibiting antibodies; 43 women remained seronegative through pregnancy. JC virus-specific immunoglobulin M was not demonstrated in umbilical cord sera of six infants born to mothers showing reactivation or in 300 additional umbilical cord sera from normal pregnancies.
Cellular and humoral immunity in subacute sclerosing panencephalitis
Authors: Dhib-Jalbut S S , Abdelnoor A M , Haddad F S
Published: January 2020

Cellular and humoral immunity was studied in 26 patients with subacute sclerosing panencephalitis. Results were compared with those of 14 normal controls and 11 patients suffering from other neurological disorders. It was shown that cellular and humoral immune responses are adequate in subacute sclerosing panencephalitis. The persistently elevated levels of serum immunoglobulin G (IgG) and IgA indicated a persistent infection, and their progressive rise in later stages correlated with the progressive nature of the illness. IgG progressively increased with the clinical stage in the cerebrospinal fluid unaccompanied by a corresponding rise in the measles antibody titer. This suggests that antigenic determinants other than those tested play a role in the production of IgG in the cerebrospinal fluid. The progressive increase in the ratio of cerebrospinal fluid to serum IgG with the advance of the disease suggests synthesis of IgG locally in the central nervous system. Elevated measles antibody titer in serum and cerebrospinal fluid is a consistent aid in the diagnosis of subacute sclerosing panencephalitis. It is more specific in cerebrospinal fluid than in serum. Its level did not vary significantly with the clinical stages or duration of illness. Depressed serum complement activity has been detected in some subacute sclerosing panencephalitis patients in whom serum levels of the third and fourth components of the complement were normal.
Age-related susceptibility of mice to ocular challenge with Pseudomonas aeruginosa exotoxin A
Authors: Berk R S , Iglewski B H , Hazlett L D
Published: January 2020

We studied the responses of mice to ocular challenge with purified exotoxin A from Pseudomonas aeruginosa in 5-, 10-, 16-, 21-, and 30-day-old animals. In the absence of trauma, injection of 3 to 6 microgram of exotoxin per mouse beneath the fused eyelids of 5-day-old Swiss-Webster mice resulted in death of all animals within 24 h. Administration of 1.5, 0.75, and 0.375 microgram of exotoxin per mouse resulted in 24-h mortality rates of 50, 22, and 20%, respectively. Additional deaths were recorded throughout the next 4 days. Similar lethality results were obtained with 10-day-old animals that received equivalent amounts of exotoxin beneath the fused eyelid and in these experiments, the 72-h 50% lethal dose was 0.49 microgram of exotoxin per mouse. Mice that were 16 and 21 days old, whose eyelids were open, each received from 0.375 to 15 microgram of exotoxin topically applied to the surface of a wounded cornea. Cataracts were observed within 1 week in both groups, and none of the animals that received the higher concentrations of toxin died. Young adult (30-day-old) animals also received from 1.8 to 15 microgram of exotoxin topically on the surfaces of wounded corneas. Corneal swelling and slight opacity were observed at 24 h and within 1 month; 80% of these mice had cataracts of the ocular lens.
Role of interbacterial adherence in colonization of the oral cavities of gnotobiotic rats infected with Streptococcus mutans and Veillonella alcalescens
Authors: McBride B C , Van der Hoeven J S
Published: January 2020

The role of interbacterial adherence in the colonization of the rate oral cavity was investigated with aggregating and nonaggregating strains of Veillonella alcalescens and Streptococcus mutans. V. alcalescens V-1 and S. mutans M-7 rapidly formed large stable aggregates when mixed in vitro. Aggregates could be reduced in size by sonication, but they could not be completely dispersed, indicating that bonding between the organisms was strong. V. alcalescens V-1 did not coaggregate with S. mutans C67-1, and V. alcalescens OMZ193 did not coaggregate with either S. mutans strain C67-1 or M-7. Osborne-Mendel rats monoassociated with either S. mutans C67-1 or M-7 were inoculated with veillonellae, molar teeth were removed at 2 h and at 14 days, and the number of veillonellae was determined. At 2 h post-inoculation there were 600 times as many colony-forming units of V. alcalescens V-1 adherent to the teeth of animals monoassociated with S. mutans M-7 when compared with animals monoassociated with the nonaggregating S. mutans C67-1. The number of colony-forming units of V. alcalescens V-1 was 1,000 times greater than the number of nonaggregating V. alcalescens OMZ193 in S. mutans M-7-infected animals. Similar results were obtained when teeth were samples 14 days after inoculation. Veillonellae inoculated into the mouths of germfree animals rapidly disappeared from tooth surfaces.
Vascular permeability activity in Escherichia coli heat-stable enterotoxin
Authors: Craig J P , Yamamoto K , Takeda T , Takeda Y , Miwatani T
Published: January 2020

Purified heat-stable enterotoxin (ST) prepared from supernatants of Escherichia coli strain 53402 A-1, isolated from a patient with diarrhea, caused an increase in the permeability of the small blood vessels of the skin of adult rabbits after intracutaneous injection. Increased permeability was manifested by localized accumulation of intravenously injected blue dye at the injection sites. Permeability factor (PF) activity reached a peak 1 h after injection, and recovery of normal permeability was nearly complete in 3 h. Residual PF activity had disappeared by 24 h. Dose-response curves demonstrated a straight-line relationship between the logarithm of the dose and mean blueing diameter over a range of 3 to 12 mm. The PF assay was less sensitive that the suckling mouse assay, and adult rabbits varied in their sensitivity to the PF effect. Five to 100 mouse units of ST were required to consistently evoke strong and unequivocal blue lesions of 7 mm or more in diameter. PF activity was reduced 50 to 70% by heating at 70 degrees C for 30 min, 60 to 80% by boiling for 30 min, and 95 to 98% by autoclaving for 15 min, but it was unaffected by treatment with cholera antitoxin. These findings are consistent with the notion that PF activity is a property of the ST molecule itself. This PF assay cannot be used for the detection of ST in crude culture supernatant fluid because of low sensitivity and the presence of nonspecific PF effects of culture media and other E. coli products.
Autorosette formation of erythrocytes on peripheral blood mononuclear cells in dogs vaccinated with canine distemper live-virus vaccine
Authors: Chandler J P , Yang T J
Published: January 2020

A time course study of the peripheral blood leukocytes of dogs vaccinated with canine distemper live virus (a paramyxovirus) vaccines showed that autorosette-forming leukocytes appeared from day 3 to day 10 after vaccination. The number of these cells peaked at day 7 when as many as 35% of mononuclear cells formed rosettes with autologous erythrocytes. In contrast, in nonvaccinated dogs, only 0.6 +/- 0.3% (standard error of the mean) of mononuclear cells formed rosettes throughout the 2-week period.
Differentiation of members of the human herpesviridae family by radioimmunoassay
Authors: Smith K O , Kennell W
Published: January 2020

Many individuals who are seronegative for one member of the human Herpesviridae family are strongly seropositive for other members. Using sera from such individuals, the radioimmunoassay technique demonstrated absence of antigen-antibody cross-reactions between varicella-zoster virus (VZV) and herpes simplex virus (HSV) at levels of less than one part in 1,000. Sera containing antibody to both HSV and VZV were absorbed with antigens of one agent without significantly altering the amount of remaining antibody to the other antigen. This further suggests that HSV and VZV do not share a common antigen. The same radioimmunoassay technique and serum absorption method that revealed no serological cross-reactions between HSV and VZV revealed the expected cross-reaction between HSV type 1 (HSV-1) and HSV-2. Reciprocally absorbed anti-HSV-1 and anti-HSV 2 sera were able to differentiate the two HSV types reliably. No cross-reactions were seen between cytomegalovirus, VZV, and HSV or between Epstein-Barr virus, VZV, and HSV. We postulate that heterotypic antibody responses sometimes observed for VZV after primary infections by HSV may not be due to shared antigens, but to activation of latent VZV infections, release of new VZV antigens, and consequent stimulation of new antibody production to VZV.
Cell-mediated immunity in American visceral leishmaniasis: reversible immunosuppression during acute infection
Authors: Carvalho E M , Teixeira R S , Johnson W D
Published: January 2020

Cell-mediated immunity was assessed in 14 Brazilian patients with acute untreated American visceral leishmaniasis (AVL) and in 11 healthy patients successfully treated 1 to 14 years previously. The diagnosis of AVL was established by demonstration of leishmania in bone marrow aspirates. The responsiveness of peripheral blood mononuclear cells to Leishmania chagasi antigens and phytohemagglutinin was studied in vitro. Soluble preparations of L. chagasi antigens were obtained from frozen-thawed promastigote cultures. L. chagasi antigen-stimulated lymphocytes from untreated AVL patients were unresponsiveness and incorporated a mean of 1.2 +/- 0.5 X 10(-3) cpm after a [3H]thymidine pulse. The cured AVL patients had 19.1 +/- 7.2 cpm, and 15 normal control subjects had 0.8 +/- 0.1 cpm. There were no differences in the response of controls and either untreated or cured AVL patients to phytohemagglutinin stimulation. Three of four untreated AVL patients responded to L. chagasi antigens when studied 2 to 4 weeks after therapy. The impaired response of lymphocytes from untreated AVL patients could not be attributed to either reduced numbers of circulating T cells or the inhibitory effect of monocytes or serum factors.
Fibrinogen enhances complement-mediated augmentation of retention of polymorphonuclear leukocytes by nylon columns
Authors: Phair J P , Bassaris H P , Morlock B A
Published: January 2020

Retention of polymorphonuclear leukocytes (PMN) by nylon columns is significantly increased when PMN are suspended in zymosan-activated plasma. In zymosan-activated plasma, 25.8 +/- 4.9% of PMN were retrained as compared with 11.1 +/- 2.7% suspended in zymosan-activated serum (ZAS) (P = 0.001) and 7.9 +/- 3.2% in fresh serum (P = 0.0005). Addition of heated plasma (56 degrees C for 30 min) to ZAS restored optimal retention. These results suggested a role for a heat-stable factor(s) in plasma, which augmented complement-mediated enhancement of PMN adhesiveness. This study was designed to determine whether fibrinogen enhanced retention by nylon columns of PMN in the presence of activated complement. Addition of defibrinated plasma to ZAS failed to enhance adhesiveness to nylon. The retention of PMN suspended in ZAS was 11.1 +/- 2.7%, as compared with 10.5 +/- 3.7% in ZAS plus defibrinated plasma. Retention of PMN suspended in ZAS plus fibrinogen was 27.92 +/- 13.2% as opposed to 16.35 +/- 7.5% (P = 0.045) in ZAs. In contrast, retention of cells in serum was 12.96 +/- 7.5%. These results suggest that the process which enhances PMN adhesiveness involves the interaction of cells, activated complement, and fibrinogen.
Pulmonary opsonins in Klebsiella pneumoniae pneumonia in rats
Authors: Coonrod J D
Published: January 2020

Klebsiella pneumoniae was inoculated intrabronchially into rats, and bronchoalveolar lavage fluid and sera were obtained during the ensuring pneumonia. Klebsiellae recovered by lavage were not maximally coated with C3, as judged by studies with fluorescent antibody, whereas the organisms could be coated fully with C3 by a brief incubation in rat serum. The levels of C1 and C3 in lavage fluid obtained during infection were only a small fraction of the levels in the serum, and klebsiellae were not opsonized during incubation with concentrated lavage fluid. Systemic decomplementation did not affect the severity of K. pneumoniae pneumonia, as judged by the measurement of lung weight or by the numbers of klebsiellae in the lungs, but decomplemented rats had a larger number of klebsiellae in the blood at 24 h of infection than did controls. There were fewer klebsiellae in the lungs 4 h after inoculation of preopsonized organisms than after inoculation of organisms which were incubated in control (heat-inactivated) sera. These studies indicate that the concentration of complement and heat-labile opsonins within the alveoli is lower than that in the systemic circulation and is not adequate for effective opsonization of klebsiellae.
Isolation of the intracellular stage of Trypanosoma cruzi and its interaction with mouse macrophages in vitro
Authors: Carvalho R M , Meirelles M N , de Souza W , Leon W
Published: January 2020

Interaction between Trypanosoma cruzi spheromastigotes (amastigotes) and mouse macrophages was studied. The spheromastigotes, isolated from the spleens of infected mice, were incorporated and digested by the macrophages. By use of horseradish peroxidase labeling of the macrophage lysosomes we showed that fusion of lysosomes with phagocytic vacuoles containing T. cruzi occurred. Parasites showing alterations indicative of digestion were seen inside the phagocytic vacuoles. Our results suggest that intracellular sphermastigotes of T. cruzi, isolated from the spleens of infected mice, and not able to induce a protective infection in mouse macrophages maintained in vitro.
Ability of Neisseria gonorrhoeae, Neisseria meningitidis, and commensal Neisseria species to obtain iron from transferrin and iron compounds
Authors: Mickelsen P A , Sparling P F
Published: January 2020

The ability of Neisseria species to use iron compounds and to compete with iron-binding proteins was examined with deferrated defined medium and the iron chelator deferoxamine. All Neisseria species were able to assimilate a variety of ferric and ferrous iron salts. They were not able to efficiently solubilize an inorganic iron salt such as ferric nitrate, but were able to use iron chelated by citrate, oxalacetate, pyrophosphate, or nitrilotriacetate. Each of the 95 Neisseria isolates examined was able to use hemin as a sole source of iron, and most, but not all, of the isolates were able to obtain iron from hemoglobin. Heated human serum stimulated growth of all gonococci, meningococci, and some commensal Neisseria species in iron-deficient medium. All gonococci and meningococci were able to scavenge iron from 25% saturated transferrin, whereas most commensal organisms were inhibited by this iron-binding protein. The ability to compete with transferrin was specific, since partially saturated conalbumin was bacteriostatic for all Neisseria species. Although the pathogenic Neisseria species were able to compete more efficiently with transferrin for iron than were the nonpathogenic Neisseria species, no correlation was observed between the virulence of different strains or colony types of gonococci and the ability to scavenge iron in vitro from transferrin or other chelators.
Experimental retrograde pyelonephritis and cystitis induced in rabbits by a group D Streptococcus sp.: serum antibody assay by a hemagglutination test
Authors: Desnottes J F , Bensman A , Ave-Virat A , Fontaine J L
Published: January 2020

Experimental models of urinary tract infection caused by a group D Streptococcus sp. in rabbits are described: retrograde pyelonephritis was induced by injecting 10(9) group D streptococci into the renal pelvis and obstructing the ureter by ligature for 24 h; cystitis was induced by injecting 5.10(9) group D streptococci through a transurethral catheter. The animals were observed for 3 months. Microbiological data from the urine and from the renal parenchyma were well correlated in 12 of 14 animals. A hemagglutination test for titration of serum antibodies in these infected rabbits is described. Before the beginning of experimentation, hemagglutination titers for all animals were below 160. During experimentation, titers for rabbits with cystitis were always below 640; in those with pyelonephritis, the highest titer was much greater than 640. These results show a positive correlation between serum antibody levels and the localization of urinary tract infection.
Serum bacterial reaction by the alternative pathway of complement: potentiation by target multiplicity and modulation by serum factors
Authors: Fietta A , Fortunato A , Dos Santos C , Grassi F , Siccardi A G
Published: January 2020

The bactericidal reactions of normal human serum and of ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid (trisodium salt)-Mg2+-treated human serum differ in a number of aspects. The latter reaction was shown (i) to require the integrity of the alternative pathway of complement, (ii) to display two levels of efficiency depending on the concentration of target bacteria, and (iii) to be modulated by the addition of thermostable serum fractions with inhibitory and stimulatory activities. The inhibitory activities were characterized to a certain extent; they comprised several glycoprotein species of molecular weights between 60,000 and 20,000. The stimulatory activities could be measured only after depletion of the inhibitors by concanavalin A-Sepharose or heat-killed bacteria and could be fractionated into several peaks by gel filtration.
Two antigenic groups of human coronaviruses detected by using enzyme-linked immunosorbent assay
Authors: Macnaughton M R , Madge M H , Reed S E
Published: January 2020

Paired sera from volunteers inoculated with one of the five recently isolated strains of human coronavirus (HCV), AD, GI, HO, PA, and RO, none of which has been grown in tissue culture, or with strain OC38 were tested against coronavirus antigens by enzyme-linked immunosorbent assay. When HCV strains OC43, 229E, or the 229E-related tissue culture-adapted strains PR and TO were used as antigens, it was shown that all strains fell into one of two antigenic groups. The HCV OC43 group was comprised of strains OC43, GI, HO, and RO, and the HCV 229E group contained strains AD and PA as well as the tissue culture-adapted strains PR, TO, and KI. Enzyme-linked immunosorbent assay of the paired sera with the coronavirus mouse hepatitis virus strain 3 as antigen confirmed the relationship of this virus to the HCV OC43 group but not to the HCV 229E group.
Immunochemical characterization of major outer membrane components from Salmonella typhimurium
Authors: Kuusi N , Nurminen M , Sarvas M
Published: January 2020

We used crossed immunoelectrophoresis to study detergent-solubilized components of the outer membrane of Salmonella typhimurium under nondenaturing conditions. The antisera used were raised against nondenatured outer membrane preparations. Lipopolysaccharide and lipoprotein were identified easily as discrete precipitates when they were solubilized with Triton X-100. However, solubilization of the porins with Triton X-100 resulted in a complex precipitate pattern, indicating incomplete dissociation of protein-protein interactions. A clear-cut pattern was obtained when the porins were first solubilized and denatured with hot sodium dodecyl sulfate, followed by removal of the sodium dodecyl sulfate and renaturation in the presence of Triton X-100. Our findings suggested that crossed immunoelectrophoresis can be used to study the antigenicity of nondenatured porins and the antibody responses to them.
Immune response to parental and rough mutant strains of Salmonella minnesota
Authors: Michael J G , Mallah I
Published: January 2020

Specificity of immune response to smooth and rough mutant strains of Salmonella minnesota was investigated. Immunization of mice with Rd and Re rough mutants resulted in formation of bactericidal plaque-forming cells directed against the lipopolysaccharide structure of both the mutants and the parental smooth strain. These antibody plaques, however, were not bactericidal for smooth strains of other gram-negative species, i.e., Escherichia coli, Salmonella typhosa, Klebsiella pneumoniae, Shigella dysenteriae, and Pseudomonas aeruginosa. Plaques produced against the smooth strain of S. minnesota or other species were not bactericidal for rough strains. It was concluded that immunization with rough mutants produces bactericidal antibodies directed against the closely related parental strain but not against smooth strains of unrelated bacterial species. The relevance of these observations to the nonspecific protection by rough mutants is discussed.
Antibody levels to bacterial peptidoglycan in human sera during the time course of endocarditis and bacteremic infections caused by Staphylococcus aureus
Authors: Zeiger A R , Tuazon C U , Sheagren J N
Published: January 2020

Sera from patients with endocarditis and bacteremia due to Staphylococcus aureus were compared for peptidoglycan-binding capacity with those from normal blood donors. Those patients treated with beta-lactam antibiotics had higher antigen-binding levels than normal donors and patients treated exclusively with vancomycin (P less than 0.01). The factor responsible for this activity was purified by affinity chromatography from a normal donor and shown to be an immunoglobulin. Specificity studies indicated that the immunodominant determinant was a peptide sequence found in peptidoglycan precursors. Since soluble peptidoglycan molecules having the precursor peptide sequence are known to be secreted by some gram-positive bacteria like Micrococcus luteus when grown in the presence of beta-lactam antibiotics, these soluble molecules may constitute the "natural" immunogen. Such a hypothesis is consistent with the study of the peptidoglycan-binding capacities in the sera of these patients during the course of treatment. For most of the responding patients studied (four of four with bacteremia and seven of nine with endocarditis), a significant increase in peptidoglycan-binding capacity was observed in sera taken 1 to 5 weeks after the initiation of beta-lactam antibiotic therapy (compared with the initial serum studied). No such increase in the peptidoglycan-binding capacity over a similar time span was noted in the sera of people not receiving beta-lactam antibiotics (none of seven).
Respiratory infectivity of a recently isolated Egyptian strain of Rift Valley fever virus
Authors: Brown J L , Dominik J W , Morrissey R L
Published: January 2020

The respiratory infectivity of a strain of Rift Valley fever virus isolated in Egypt (strain ZH-501) was compared with that of one isolate from Uganda (Entebbe strain) and two isolates from South Africa (strains SA-51 and SA-75). Studies were performed with ICR mice which were infected by exposure to infectious aerosols composed of particles with a mass median diameter of 0.96 micrometer. The respiratory median lethal doses for ZH-501, Entebbe, SA-51, and SA-75 were 2.2, 1.9, 2.6, and 1.9 log10 plaque-forming units, respectively. Although these values are statistically different, the biological implications of such differences seem unimportant. In an additional study of pathogenesis, a single group of mice was infected with 3.1 log10 plaque-forming units of ZH-501, and tissues were assayed sequentially through 96 h postinfection. Between 6 and 30 h, demonstration of an increasing virus concentration only in the lungs indicated that initial replication occurred there; however, determination of histopathological changes did not reveal evidence of pneumonia. Virus was isolated from the liver by 48 h, and the ultimate outcome of infection was a fulminating and fatal hepatic necrosis.
Characterization of rabbit corneal damage produced by Serratia keratitis and by a serratia protease
Authors: Lyerly D , Gray L , Kreger A
Published: January 2020

The structural alterations elicited in the rabbit corneal stroma by experimental Serratia marcescens keratitis and by a highly purified serratia protease preparation were compared by gross observation, biochemical analyses, and electron microscopic examination of the affected tissue. Acute inflammation, liquefactive necrosis of the cornea, and descemetocele formation occurred during the development of the infection and after the intracorneal injection of submicrogram amounts of the protease. In vitro incubation of insoluble corneal stromal tissue with the bacterium or with the protease resulted in solubilization of the stromal proteoglycan ground substance; however, specific collagenase activity was not detected. Electron microscopic examination of corneas damaged by the bacterial infection and by the protease revealed loss of ruthenium red staining of the proteoglycan ground substance and dispersal of ultrastructurally normal collagen fibrils. Thus, our findings indicate that the major corneal damage which occurs during serratia keratitis and after the injection of the serratia protease is caused by solubilization and loss of the ground substance of the tissue. In addition, the observation that the major structural alterations observed during serratia keratitis can be reproduced by the bacterial protease supports the idea that the enzyme is involved, at least in part, with the production of severe corneal damage by the bacterium.
Growth of the Pittsburgh Pneumonia Agent in Animal Cell Cultures
Authors: Rinaldo Charles R. , Pasculle A. William , Myerowitz Richard L. , Gress Francis M. , Dowling John N.
Published: January 2020

Pittsburgh pneumonia agent (
Legionella micdadei
) grew in monkey, chicken, and human cell cultures. Pittsburgh pneumonia agent grew predominantly in the cytoplasm, resulting in a nonfocal, mild cytopathic effect.
Detection of antibody-accessible proteins on the cell surface of Haemophilus influenzae type b
Authors: Hansen E J , Frisch C F , Johnston K H
Published: January 2020

A radioimmunoprecipitation method has been devised which permits the direct identification of those proteins which are both exposed on the cell surface of Haemophilus influenzae type b and accessible to antibody. Both extrinsically and intrinsically radiolabeled cells of this organism were employed as the sources of antigen in radioimmunoprecipitation experiments which involved incubation of intact bacterial cells with antisera. Several different proteins, ranging in apparent molecular weight from 33,000 to 160,000, were shown to be accessible to antibody on the cell surface of this pathogen.
Functional and metabolic properties of alveolar macrophages in response to the gas phase of tobacco smoke
Authors: Drath D B , Shorey J M , Huber G L
Published: January 2020

The effect of whole tobacco smoke and the gas phase of tobacco smoke on the metabolism and phagocytic ability of alveolar macrophages was monitored over a 30-day exposure period. It was demonstrated that both the gas phase and whole tobacco smoke induced a weight loss in exposed rats. Alveolar macrophage oxygen consumption was markedly increased by both exposure regimens. Superoxide generation was not affected by whole tobacco smoke exposure but was increased in response to the filtered gas phase. Hexose monophosphate shunt activity was not altered by either treatment. When metabolic alterations were seen in response to the separate exposures, they were seen only after a phagocytic challenge to the macrophage and not when the cell was unchallenged. Neither whole tobacco smoke nor the gas phase had any significant effect on the ability of alveolar macrophages to phagocytize a viable challenge of Staphylococcus aureus. Our results suggest that many of the metabolic and functional effects of tobacco smoke on alveolar macrophages can be attributed to the gas-phase component of whole tobacco smoke.
Mitogen- and viral antigen-induced transformation of lymphocytes from normal mink and from mink with progressive or nonprogressive Aleutian disease
Authors: An S H , Wilkie B N
Published: January 2020

Peripheral blood lymphocytes (PBL) from mink with progressive Aleutian disease (AD) were shown to be significantly less responsive to phytohemagglutinin, concanavalin A, and pokeweed mitogen than were PBL from normal mink and from mink with a nonprogressive form of AD. Response to the virus of AD was significantly greater in PBL cultures from mink with nonprogressive AD than in those from normal mink or mink with progressive AD. After experimental infection with AD virus, mink PBL were responsive to viral antigen only transiently. These findings suggest that lymphocyte responsiveness as indicated by transformation induced by mitogens or viral antigen may be an important aspect of host response to infection with the parvovirus of AD.
Mitogenicity of influenza hemagglutinin glycoproteins and influenza viruses bearing H2-hemagglutinin
Authors: Armstrong R B , Butchko G M , Kiley S C , Phelan M A , Ennis F A
Published: January 2020

The hemagglutinin glycoprotein is responsible for the mitogenic effect of influenza A viruses of the H2N2 subtype. This was indicated by the ability of viruses bearing the H2-hemagglutinin glycoprotein, regardless of its associated neuraminidase, to induce lymphocyte proliferation in normal spleen cell suspensions and by the ability of antisera with specificity for the H2-hemagglutinin to block this response. Moreover, purified hemagglutinin from representative viruses from the H0N1, H1N1, H2N2, H3N2, and influenza B subtypes were also shown to be mitogenic.
Production of exoenzyme S by clinical isolates of Pseudomonas aeruginosa
Authors: Sokol P A , Iglewski B H , Hager T A , Sadoff J C , Cross A S , McManus A , Farber B F , Iglewski W J
Published: January 2020

Exoenzyme S differs from toxin A and diphtheria toxin in that it does not adenosine diphosphate (ADP)-ribosylate elongation factor-2, but rather catalyzes the transfer of the ADP-ribose moiety of nicotinamide adenine dinucleotide to a number of different proteins in extracts of eucaryotic cells. Polyoma-transformed BHK-21 cells were isolated which were resistant to diphtheria toxin and toxin A. Extracts from these cells are ADP-ribosylated by exoenzyme S but not toxin A or diphtheria toxin, providing an assay which distinguishes between S and A activities. A total of 124 clinical isolates of P. aeruginosa were analyzed for production of toxin A and exoenzyme S. Exoenzyme S production was detected in 38% of the strains, whereas 80% of the strains produced toxin A.
Interactions of killed Listeria monocytogenes with the mouse complement system
Authors: van Kessel K P , Antonissen A C , van Dijk H , Rademaker P M , Willers J M
Published: January 2020

Incubation of mouse serum with Listeria monocytogenes involved activation of the alternative complement pathway, resulting in depletion of both classical and alternative pathway activity. The activation process gave rise to reactive (calcium- and magnesium-independent) lysis of, specifically, rabbit erythrocytes, which become resistant to this form of hemolysis by sensitization with antibodies. The possible implications of these findings for L. monocytogenes as an intracellular parasite and for rabbit erythrocytes as target cells for mouse alternative complement pathway activity are discussed.
Heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylated variants of a single polypeptide chain
Authors: Murphy P A , Cebula T A , Windle B E
Published: January 2020

Rabbit endogenous pyrogens were of about the same molecular size, but showed considerable heterogeneity of their isoelectric points. We attempted to show that this heterogeneity was attributable to variable glycosylation of a single polypeptide chain. When peritoneal exudate cells were stimulated to make pyrogens in the presence of 2-deoxy-D-glucose, there was a relatively trivial suppression of pyrogen release, and analysis by isoelectric focusing showed parallel inhibition of secretion of all the forms of endogenous pyrogen. When cells were stimulated in the presence of 3H-labeled amino acids and 14C-labeled glucosamine or glucose, the purified pyrogens were labeled with 3H but not with 14C. Macrophage membrane preparations were made which contained glycosyl transferases and could transfer sugar residues from sugar nucleotides to deglycosylated fetuin. These macrophage membrane preparations did not transfer sugars to the pI 7.3 endogenous pyrogen. Treatment of endogenous pyrogens with neuraminidase or with periodate produced no evidence suggesting that the pyrogens were glycosylated. Last, endogenous pyrogens did not bind to any of four lectins with different carbohydrate specificities. This evidence suggests that the heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylation and must have some other cause.
Role of chemotaxis in the association of motile bacteria with intestinal mucosa: in vitro studies
Authors: Freter R , Allweiss B , O'Brien P C , Halstead S A , Macsai M S
Published: January 2020

Various Sephadex G-15 fractions of pepsin-digested mucosal extract inhibited the in vitro association of cholera vibrios with mucosal slices. Inhibitory activity paralleled the taxin activity of the fractions for these bacteria. This supports the theory that inhibition of mucosal association by pepsin-digested mucosal scrapings was due to the blocking of taxin receptors on the bacterial surface. Nonchemotactic mutants were significantly less efficient than the chemotactic parent or revertant strains in associating with mucosal slices in vitro. Control experiments in which filter paper disks replaced the mucosal slices showed a comparable extent of association of chemotactic and nonchemotactic vibrios with this material. Histological studies indicated that vibrios associated predominantly with the mucus gel of the intestinal slices rather than with the mucosal epithelium or the serosal surface. Intestinal slices attracted chemotactic vibrios even after prolonged washing, suggesting continuous production of the taxin by the tissue. Inert polystyrene particles 1.1 micrometers in diameter penetrated the mucus gel of intestinal slices very poorly, but nevertheless could be detected in low numbers in the deep intervillous spaces within 15 min. In contrast, chemotactic vibrios reached the deep intervillous spaces in significantly higher numbers, whereas motile, non-chemotactic vibrios reacted like the inert particles. It is concluded that mucus gel represents a partial barrier to the penetration of particles of bacterial size and that this barrier can be invaded efficiently by motile bacteria, but only when their locomotion is guided by chemotactic stimuli.
Modified method for studying bacterial adhesion to isolated uroepithelial cells and uromucoid
Authors: Chick S , Harber M J , Mackenzie R , Asscher A W
Published: January 2020

Several problems have been encountered with the application of published methods for the study of bacterial adherence to isolated uroepithelial cells. Of particular importance is the observation that urinary mucus traps some organisms but not others. Established techniques have been modified to overcome these difficulties and so allow a distinction to be made between adherence of bacteria to uromucoid and adherence to uroepithelial cells per se. The modified method was used to assess the ability of 34 urinary isolates of Escherichia coli to adhere to uroepithelial cells, uromucoid, or both after serial subculture in nutrient broth. The ability of the organisms to produce mannose-sensitive (MS) agglutination of guinea pig erythrocytes and mannose-resistant (MR) agglutination of human erythrocytes was tested simultaneously and taken to indicate possession of MS type 1 fimbriae andated MR fimbriae, respectively. Results revealed that only MS-positive organisms adhered to uromucoid (P less than 0.001), whereas MR-positive strains showed significantly greater attachment to uroepithelial cells than did MR-negative strains (P less than 0.05). These observations demand that published data derived from the use of a methodology in which no differentiation can be made between adherence to uromucoid and adherence to cells should be interpreted with caution.
Cytadsorption of
Mycoplasma pulmonis
to Rat Ependyma
Authors: Kohn Dennis F. , Chinookoswong Narumol
Published: January 2020

Mycoplasma pulmonis
was inoculated intracerebrally into neonatal rats. Hydrocephalus was induced, and the lateral ventricles and aqueduct were examined by scanning electron microscopy. Mycoplasmas were observed to be cytadsorbed to the ependymal surface.
Experimental Cholera in Germfree Suckling Mice
Authors: Shimamura Tadakatsu , Tazume Seiki , Hashimoto Kazuo , Sasaki Shogo
Published: January 2020

Vibrio cholerae
V86 El Tor Inaba caused experimental cholera in germfree ICR suckling mice. Sucklings born of gnotobiotic mothers monoassociated with the same strain were completely protected against live oral homologous challenge.
Nonspecific suppression of initiation of memory cells in Toxoplasma gondii-infected mice
Authors: Suzuki Y , Watanabe N , Kobayashi A
Published: January 2020

The effect of Toxoplasma infection on initiation and expression of memory cells to dinitrophenol (DNP)-conjugated protein antigens in humoral immune responses was studied in mice. Marked suppression in the initiation of memory cells to DNP-conjugated keyhole limpet hemocyanin occurred in the acute phase of infection. However, once the memory cells were induced before infection, expression of the memory cells was not affected. Moreover, the suppression of priming occurred on both T and B cells. The suppressive effect was observed in all immunoglobulin classes tested, i.e., immunoglobulin M (IgM), IgG1, IgG2, and IgE, regardless of the four kinds of DNP-conjugated protein antigens. This nonspecific suppression could be induced only by living toxoplasmas, by either the peroral or parenteral route, but not by lysed organisms. A transfer of normal spleen cells could not restore the ability of infected mice to initiate memory cells. Furthermore, the suppressive effect of the infected mice was not removed by 400 R of gamma-irradiation. These results suggested that irradiation-resistant suppressor cells cause nonspecific suppression of the initiation of memory cells in Toxoplasma-infected mice.
In vivo reactivation of herpes simplex virus in rabbit trigeminal ganglia: electrode model
Authors: Green M T , Rosborough J P , Dunkel E C
Published: January 2020

The rabbit provides an excellent model for the study of ocular herpes because herpetic keratitis in the rabbit eye resembles human disease in its clinical features and in its propensity for spontaneous recurrence. This paper presents a method for the electrical induction of multiple episodes of in vivo reactivation of latent HSV-1 infection with peripheral shedding of virus. Physiological levels of current delivered via an electrode implanted over the trigeminal ganglion of latently infected animals has enabled us to modify and synchronize virus shedding in preocular tear film and to cause multiple episodes of reactivation in a single animal. For this reason, the model is well suited for antiviral efficacy testing and provides an excellent opportunity for investigation of virus-host cell interactions in latent and recurring herpetic disease.
Shigella sonnei plasmids: evidence that a large plasmid is necessary for virulence
Authors: Sansonetti P J , Kopecko D J , Formal S B
Published: January 2020

Virulent form I Shigella sonnei strains contain a 120-megadalton plasmid that is absent in their form II derivatives, which are always avirulent and devoid of O side chains. In the present study, 165 biochemical and antibiotic traits were assessed, but no experimentally useful phenotype could be associated with this large form I plasmid. Therefore, the form I plasmids of several S. sonnei strains were tagged with the antibiotic resistance transposons Tn3, Tn5, or Tn10. Transposon-tagged form I plasmids were not self-transmissible, but could be mobilized by the plasmid R386. Form II S. sonnei transconjugants for the form I plasmid acquired both virulence and the ability to synthesize form I antigen, establishing that these properties are plasmid mediated. Further studies indicate that this 120-megadalton form I plasmid is physically unstable in any of several host bacteria and suggest that it is a member of the FI incompatibility group. Also, two commonly observed, small plasmids of S. sonnei, of 3.2 and 3.9 megadaltons, were shown to encode either colicin E1 production or resistance to streptomycin and sulfonamide, respectively.
Cell-mediated immunity and lymphocyte populations in experimental Argentine hemorrhagic fever (Junín Virus)
Authors: Carballal G , Oubiña J R , Rondinone S N , Elsner B , Frigerio M J
Published: January 2020

Guinea pigs infected with the XJ prototype strain of Junín virus reproduce the main features of Argentine hemorrhagic fever, showing hemorrhages, leukothrombocytopenia, and focal lymphoid tissue necrosis. Viral lymphotropism is shown by the presence of viral antigens, severe cytopathic effect, and high virus titers in lymphoid organs. A pronounced depression of humoral immune response to sheep erythrocytes as well as to the virus is described. This study was carried out to determine whether cellular immune response was also modified and which cell populations were affected. Delayed hypersensitivity skin reaction to purified protein derivative was found to be markedly depressed after infection. A noticeable decrease in both percentages and absolute T lymphocyte numbers, detected by E rosettes, in spleen and lymph nodes, together with a low absolute T cell number in peripheral blood, were observed. Total cell counts in spleen, lymph nodes, and peripheral blood were also reduced. On the contrary, no modification in percentages of B lymphocytes, as measured by EAC rosettes, was found. These results indicate that cell-mediated immunity is markedly impaired in guinea pigs infected with the XJ strain of Junín virus. Its relationship with the pathogenesis of the disease is discussed.