bluuebunny/crossref_metadata_2025 huggingface dataset:
A phylogenetic tree of 16S rRNA sequences from sulfate-reducing bacteria in a sandy marine sediment
Authors: Devereux R , Mundfrom G W
Published: January 2020

The divergence of 16S rDNA sequences in marine sediment was investigated. Twenty unique partial sequences were found among 33 cloned following PCR. Thirteen shared 82 to 91% similarity with sequences of delta subclass sulfate-reducing bacteria. Three contained the target sequence for a sulfate-reducing bacterium-specific oligonucleotide probe designed from pure-culture studies.
Starvation-Induced Stress Resistance in
Lactococcus lactis
subsp.
lactis
IL1403
Authors: Hartke Axel , Bouche Sandrine , Gansel Xavier , Boutibonnes Philippe , Auffray Yanick
Published: January 2020

Carbohydrate-starved cultures of
Lactococcus lactis
subsp.
lactis
IL1403 showed enhanced resistance to heat, ethanol, acid, osmotic, and oxidative stresses. This cross-protection seems to be established progressively during the transitional growth phase, with maximum resistance occurring when cells enter the stationary phase. Chloramphenicol or rifamycin treatment does not abolish the development of a tolerant cell state but, on the contrary, seems to provoke this response in
L. lactis
subsp.
lactis.
Total and Free Ergosterol in Mycelia of Saltmarsh Ascomycetes with Access to Whole Leaves or Aqueous Extracts of Leaves
Authors: Newell Steven Y.
Published: January 2020

Three species of saltmarsh ascomycetes were grown in the presence of all of the constituents of their natural substrate (leaves of cordgrass) or were presented only with aqueous extracts of the leaves. These two growth-condition treatments had no significant effect on total ergosterol content of the fungal mycelia, contrary to an earlier hypothesis that availability of plant lipids would lower fungal ergosterol contents. Mycelial content of free ergosterol was about twice as variable as that for total (free plus esterified) ergosterol. Total ergosterol (data pooled for all species) was strongly correlated to organic mycelial mass (
r
2
= 0.43,
P
< 0.00001, and slope = 4.59 μg of ergosterol mg of organic mass
-1
).
Persistence of Adenovirus 5 in Guinea Pigs
Authors: Faucon N. , Chardonnet Y. , Sohier R.
Published: January 2020

One intracardiac inoculation of adenovirus 5 in guinea pigs leads to virus persistence in different organs, viz., 5 days in lungs and liver, 14 days in blood and lymph nodes, and 56 days or more in the spleen. After cultivation of tissue cells for 1 week, virus was recovered from blood, lymph nodes, or spleen lymphocytes, but virus could be detected directly in cells only when organs were removed within 48 h of inoculation. To determine how the virus persisted in low concentrations and as a latent infection, spleens were primarily selected for study by three techniques: homogenization of spleens, suspended Maitland fragment cultures, and in vitro cultivation of spleen cells. The last procedure showed virus in fibroblast-like cells (probably macrophages or reticuloendothelial cells) for 56 days after infection of guinea pigs. With other methods, the virus was found only within the first 2 days after inoculation.
Insect Immunity I. Characteristics of an Inducible Cell-Free Antibacterial Reaction in Hemolymph of
Samia cynthia
Pupae
Authors: Boman Hans G. , Nilsson-Faye Ingrid , Paul Kerstin , Rasmuson Torgny
Published: January 2020

Pupae of the silk moth,
Samia cynthia
, were found to contain an inducible antibacterial activity in their hemolymph. This immunity response was provoked by primary infections with either
Escherichia coli
K-12 or
Enterobacter cloacae.
In both cases the antibacterial activity was directed chiefly towards
E. coli.
During standard conditions, 1% of hemolymph could kill 10
3
to 10
4
viable
E. coli
, strain D31, within 5 min. A lower level of antibacterial activity was induced by injections of a sterile salt solution. The killing of strain D31 followed single-hit kinetics, and increasing rate constants were obtained for increasing amounts of hemolymph. The reaction was sensitive to pretreatment with trypsin and it was protected by reducing agents. The activity was inhibited by microgram quantities of lipopolysaccharide (LPS) prepared from certain LPS mutants of
E. coli
K-12. A comparison of the susceptibility showed that “heptose-less” LPS mutants were more sensitive to killing than other strains. During standard conditions hemolymph will lyse both
E. coli
and
Micrococcus lysodeikticus.
Lysis of
E. coli
followed a multi-hit kinetics and it was inhibited by LPS, whereas lysis of
M. lysodeikticus
was unaffected by LPS. Hemolymph was fractionated on Sephadex G-200, and the lytic activities were recovered in partly overlapping peaks. Reconstitution with pooled fractions gave synergistic effects with the killing assay.
Biological Properties of Two Strains of Simian Virus 40 Isolated from Patients with Progressive Multifocal Leukoencephalopathy
Authors: Narayan Opendra , Weiner L. P.
Published: January 2020

Biological properties of two strains of simian virus 40 (SV40) from brains of two patients with progressive multifocal leukoencephalopathy (PML) have been compared to those of a standard laboratory strain of SV40. Infectivity of both SV40-PML viruses was resistant to treatment with chloroform, low pH, and 50 C for 120 min. African green monkey kidney and BSC-1 cells were the most sensitive for viral replication, and cytopathology in these cultures was indistinguishable from that caused by SV40. Both viruses formed plaques in these cells. but, in African green monkey kidney cells, strain 1 virus produced plaques measuring 2 mm in diameter whereas strain 2 virus produced pleomorphic plaques varying from 1 to 10 mm in diameter. Hamster cells were not permissive for viral replication, and infection resulted only in viral transformation. Inoculation of human fetal glial cells resulted in a permissive lytic infection of one cell type and a persistent infection with only partial expression of the viral genome in the other. No morphological evidence of transformation was evident in the latter cells. Both strains of SV40-PML viruses were neutralized by commercial anti-SV40 serum, but in reciprocal kinetic neutralization tests differences in
K
values were noted when each was compared to SV40. Both viruses showed oncogenicity for hamsters, producing undifferentiated sarcomas when injected subcutaneously and choroid plexus papillomas after intracerebral inoculation. All hamster tumor cells contained intranuclear immunofluorescent tumor antigen. This was indistinguishable from SV40 T antigen in reciprocal staining reactions using hamster anti-T antibody induced by the two SV40-PML agents and SV40. These two human agents appear therefore to be new variants of simian virus 40.
Mycolic Acids from “Noncultivable” Mycobacteria
Authors: Etemadi A. H. , Convit J.
Published: January 2020

Chromatographic analysis, coupled to mass spectrometry with a high-resolution mass spectrometer, of materials isolated from skin lesions of patients with lepromatous leprosy allows the recognition of characteristic mycobacterial products, mycolic acids. This finding indicates that the “noncultivable” bacteria responsible for leprosy are mycobacteria.
Growth of Murine Cytomegalovirus in a Heterologous Cell System and Its Enhancement by 5-Iodo-2′-Deoxyuridine
Authors: Plummer G. , Goodheart C. R.
Published: January 2020

Mouse cytomegalovirus replicated in rabbit kidney cultures, a cell system of nonrodent origin. However, the sensitivity of these cultures, and the yields of virus therefrom, were lower than those of mouse cultures. Although a cytopathic effect developed in rabbit kidney cultures inoculated with sufficient amounts of the virus, such cultures were unsatisfactory for plaque assay. This was also true when rabbit fibroblast cultures were used, even though the murine cytomegalovirus replicated much better in mouse fibroblasts than in mouse kidney cultures, the latter of which contained extensive areas of epithelial cells. Viral growth in rabbit kidney cells was considerably enhanced when those cells had been initiated and grown in the presence of 5-iodo-2′-deoxyuridine; not only were the viral titers increased, but also the clarity and distinctness of the inclusion bodies.
Immunity to
Candida albicans
Induced by
Listeria monocytogenes
Authors: Marra Shirley , Balish Edward
Published: January 2020

Immunity to
Candida albicans
was studied in Swiss-Webster white female mice. Lethal and sublethal infections with
C. albicans
did not enhance immunity to a subsequent
Listeria monocytogenes
challenge. Mice sensitized to
L. monocytogenes
and then challenged with
C. albicans
intravenously were able to reduce the population of
C. albicans
in their kidneys after being boosted (rechallenged) with
L. monocytogenes.
However, the acquired cellular immunity so induced was very short-lived. Both
C. albicans
-sensitized and nonsensitized control mice showed an immediate-type and delayed-type skin test response to the cell wall antigen(s) of
C. albicans
but not to the cytoplasmic antigen(s). There did not appear to be any correlation between increase in skin test response and progression of the candida infection in mice.
Beta-Glucuronidase Response of Cells Infected with Adenovirus Types 5 and 12
Authors: Bardell D. , Metcalf T. G.
Published: January 2020

Beta-glucuronidase activity was investigated during a 48-h period in which virus replication and changes in cell morphology occurred. Infection of an established line of chimpanzee liver cells with either nononcogenic adenovirus 5 or highly oncogenic adenovirus 12 under one-step growth conditions produced differing patterns of enzyme activity. There was an increase in total activity and also enhanced leakage of beta-glucuronidase from cells infected with adenovirus 12. In contrast, the enzymatic pattern of cells infected with adenovirus 5 was similar to that of uninfected cells. Hydrocortisone prevented the abnormal release of beta-glucuronidase from adenovirus 12-infected cells. The compound had no effect on total enzyme activity or on virus replication and the development of cytopathology.
Alteration of Vascular Permeability in Rabbits by Culture Filtrates of
Bacillus cereus
and Related Species
Authors: Glatz Bonita A. , Spira W. M. , Goepfert J. M.
Published: January 2020

Crude culture filtrates of strains of
Bacillus cereus, B. thuringiensis, and B. mycoides
caused an increase in vascular permeability when injected intradermally into rabbits. The time course of the change in permeability was determined, and could easily be distinguished from a more transient effect induced by purified (from
B. cereus
) phospholipase C. The properties of the responsible factor were found to be similar to those reported for the guinea pig dermal factor and the ileal loop fluid inducing factor, namely: synthesis by vigorously aerated, logarithmically growing cells; inactivation by heating at 56 C; non-dialyzability; precipitation with ammonium sulfate; and antigenic characteristics. Permeability factor was not related to either the phospholipase C or the hemolysin produced by
B. cereus.
Activity of this
B. cereus
toxin, as measured in the vascular permeability and ileal loop assays, can easily be quantitated, but the greater simplicity, reliability, and economy of the vascular permeability test make it the method of choice for screening cultures or following toxin purification.
Suppression of Cell-Mediated Immunity in Experimental African Trypanosomiasis
Authors: Mansfield John M. , Wallace John H.
Published: January 2020

Adult New Zealand white rabbits were experimentally infected with a parasitic African hemoflagellate,
Trypanosoma congolense
, and were subsequently tested for in vivo and in vitro aspects of cell-mediated immune function. Chronically infected rabbits were sensitized to mycobacterial protein and skin-tested with purified protein derivative; all infected animals demonstrated much milder skin-test responses to antigen than control groups. Similarly, peripheral blood lymphocyte responses in vitro to purified protein derivative and, as well, to phytohemagglutinin were markedly suppressed. Supernatant fluids of antigen-stimulated lymph node cell cultures from
T. congolense
-infected rabbits failed to demonstrate migration inhibitory factor activity but did possess normal levels of blastogenic factor activity. An active infection was necessary for demonstration of suppressed immune responses, and components present in infected rabbit serum were apparently not responsible for the observed abnormalities. Suppression of T-lymphocyte subpopulations may well explain the occurrence of numerous immunological aberrations arising during human and animal infections with the African trypanosomes.
Pyrogenic Specificity of Streptococcal Exotoxins, Staphylococcal Enterotoxin, and Gram-Negative Endotoxin
Authors: Brunson K. W. , Watson Dennis W.
Published: January 2020

Streptococcal exotoxin and staphylococcal enterotoxin share several biological properties, including pyrogenicity, lymphocyte mitogenicity, and enhancement of gram-negative endotoxin lethality. These analogies of the toxins prompted comparative pyrogenic studies. When American Dutch rabbits were immunized by repeated intravenous injections of small amounts of staphylococcal enterotoxin, they exhibited a decreased febrile response upon challenge when compared with control animals not previously injected. The same animals responded similarly to control groups when challenged with streptococcal exotoxin A, B, or C. No cross-reactivity was observed in reciprocal cross-tests, using animals immune to the streptococcal toxins and challenging with staphylococcal enterotoxin. No cross-reactivity between either the streptococcal or staphylococcal toxins and bacterial endotoxin was observed.
Brain Polymorphonuclear Leukocyte Quantitation by Peroxidase Assay
Authors: Smith A.. L. , Rosenberg I. , Averill D. R. , Moxon E. R. , Stossel T. , Smith D. H.
Published: January 2020

Rat brain polymorphonuclear infiltration was quantitated by spectrophotometric assay of myeloperoxidase activity. Peroxidase was assayed by following the oxidation of
o
-dianisidine in the presence of a hydrogen peroxide generating system (glucose-glucose oxidase). Enzyme activity was proportional to the number of polymorphonuclear leukocytes present at densities between 10
5
and 10
6
cells. Brain tissue did not have detectable peroxidase activity and polymorphonuclear leukocytes added to brain homogenates were quantitatively estimated. In infant rats with
Haemophilus influenzae
meningitis, the correlation between the number of polymorphonuclear leukocytes found in brain by peroxidase activity measurement and independent histological grading was not precise, but there was an exact correlation in predicting presence or absence of polymorphonuclear leukocytes. Myeloperoxidase activity appears to afford a rapid convenient tool for quantitative determination of tissue polymorphonuclear leukocyte content.
Stimulation of Peripheral Blood Lymphocytes by Herpes Simplex Virus in Vitro
Authors: Scriba M.
Published: January 2020

A method for stimulating sensitized lymphocytes by inactivated herpes simplex virus was established by using cultures of washed whole blood cells. The development of the immune response of herpes simplex virus-infected guinea pigs was examined at different times in the 4-month period after infection. Humoral and cellular immune responses were compared in individual animals by measuring lymphocyte stimulation ratios and neutralizing serum antibodies.
Local Antibody Production Against the Murine Toxin of
Yersinia pestis
in a Golf Ball-Induced Granuloma
Authors: Hillam Robyn P. , Tengerdy Robert P. , Brown George L.
Published: January 2020

The method of Garra and Baygorria, for localized antibody production, has been adapted for obtaining high-titered and monospecific antibodies against the murine toxin of
Yersinia pestis.
A hollow, perforated plastic golf ball surgically implanted under the skin of rabbits induced the formation of a granuloma. When the murine toxin of
Y. pestis
was injected directly into the granulomatous cavity, an increased amount of antibody was found in the granuloma fluid as compared with serum or with serum antibody obtained by conventional immunization. The granuloma antibody consisted mainly of immunoglobulin G, probably produced locally by lymphoid cells of the granuloma. The immune granuloma fluid and the granuloma tissue were rich in plasma cells and lymphocytes. The chemical composition of the granuloma fluid indicated that it was a transudate.
Comparison of the Action of
Escherichia coli
Enterotoxin on the Thymocyte Adenylate Cyclase-Cyclic Adenosine Monophosphate System to That of Cholera Toxin and Prostaglandin E
1
Authors: Zenser Terry V. , Metzger Joseph F.
Published: January 2020

Mouse thymocytes were used to compare mechanisms by which
Vibrio cholerae
and heat-labile
Escherichia coli
enterotoxins activate the adenylate cyclase-cyclic adenosine monophosphate (AMP) system. Both enterotoxins had their time-delayed increase in cyclic AMP neutralized by antisera to
V. cholerae
or
E. coli
enterotoxin, blocked by low concentrations of ganglioside G
M1
, and destroyed by prior heating. Enterotoxin activation of adenylate cyclase was similarly affected. By contrast, prostaglandin E
1
-mediated increases in cyclic AMP were not affected by specific antitoxins or gangliosides. Combination of maximal stimulatory doses of both enterotoxins did not produce additive increases in cyclic AMP. Wash experiments suggested that both enterotoxins bind rapidly and tightly to thymocytes at 37 C. However, lowering the incubation temperature to 8 C reduced the affinity of
E. coli
enterotoxin but not cholera toxin for thymocytes. Results suggest that heat-labile
E. coli
enterotoxin and cholera enterotoxin may activate the same adenylate cyclase enzyme by similar mechanisms.
Neutralizing Antibody Response of Guinea Pigs to Lymphocytic Choriomeningitis Virus
Authors: Webster Janice M. , Kirk B. E.
Published: January 2020

A 24-h neutralization test that is based on fluorescent cell counting was used for the detection and quantitative determination of serum-neutralizing antibody against lymphocytic choriomeningitis virus. The earliest manifestation of serum-neutralizing antibody in guinea pigs was shown to occur within 1 week after inoculation with lymphocytic choriomeningitis virus. Within 11 weeks, serum-neutralizing antibody increased from 20- to 300-fold. Neutralizing end points of serum samples, obtained from 3 through 11 weeks, were enhanced as much as sevenfold by complement. Anti-guinea pig immunoglobulin G or anti-whole guinea pig serum potentiated the neutralizing activity of serum as much as 20- and 40-fold, respectively.
Reduced Nicotinamide Adenine Dinucleotide and Reduced Nicotinamide Adenine Dinucleotide Phosphate Diaphorase Activity in Human Polymorphonuclear Leukocytes
Authors: DeChatelet Lawrence R. , McPhail Linda C. , Mullikin Debra , McCall Charles E.
Published: January 2020

Total reduced nicotinamide adenine dinucleotide (NADH) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activities were examined in human neutrophils. Approximately two-thirds of each enzyme activity was located in the granule fraction with the remainder in the soluble. The activities in a 27,000 ×
g
supernatant from a sonic extract of human polymorphonuclear leukocytes were characterized. Both NADH and NADPH diaphorase were insensitive to cyanide and azide and showed greater activity at acid pH.
K

m

values for nitroblue tetrazolium were not markedly different (33 μM with NADH and 12 μM with NADPH), but there was a 40-fold difference in
K

m

for the reduced pyridine nucleotides (10 μM with NADH and 400 μM for NADPH). Since the intracellular concentration of both nucleotides is estimated to be about 50 μM, it is much more likely, from a kinetic argument, that the respiratory burst of phagocytosis is intiated by the oxidation of NADH rather than of NADPH.
Effect of Synthetic Disaccharide-Protein Conjugate as an Immunogen in
Salmonella
Infection in Mice
Authors: Lindberg A. A. , Rosenberg L. T. , Ljunggren Å. , Garegg P. J. , Svensson S. , Wallin N.-H.
Published: January 2020

The synthetic disaccharide 3-
O
-α-tyvelopyranosyl-α-D-mannopyranoside, identical to the O antigen 9 determinant in
Salmonella
, covalently linked to bovine serum albumin and suspended in Freund complete adjuvant, was used as an immunogen in mice. Antibodies in high titer were formed against the O9 determinant as estimated by a bactericidal assay, whereas only low titers of hemagglutinating antibodies were found. A sensitive in vivo assay demonstrated that in immunized mice, after challenge with two strains of equal virulence but with different O antigens (O9, 12 and O4, 5, 12, respectively), the growth of the strain with the O9 determinant was suppressed in comparison to that with the O4 determinant.
Measurement of Intracellular Iodophilic Polysaccharide in Two Cariogenic Strains of
Streptococcus mutans
by Cytochemical and Chemical Methods
Authors: DiPersio J. R. , Mattingly S. J. , Higgins M. L. , Shockman G. D.
Published: January 2020

Quantitative cytological and chemical methods have been developed to study the intracellular iodophilic polysaccharide (IPS) content of two strains of
Streptococcus mutans.
The cytological method uses a periodic acid-chlorite treatment of thin sections to increase the affinity of IPS for uranyl and lead salts. This results in the IPS appearing as individual electron-dense granules which can be counted for quantitative studies. As a basis for these quantitative studies, IPS was measured chemically by dissolving whole cells with hot KOH and quantitating spectrophotometrically the amount of iodine-polysaccharide complex formed.
Studies on Gonococcus Infection V. Observations on In Vitro Interactions of Gonococci and Human Neutrophils
Authors: Swanson John , Sparks Edward , Zeligs Barbara , Siam Monir A. , Parrott Carol
Published: January 2020

The association of in vitro human leukocytes with pilated, type 2
Neisseria gonorrhoeae
exceeds that for nonpilated, type 4 organisms but is less than that for nonpilated, type 4
*
gonococci. The two nonpilated forms of gonococci (types 4 and 4
*
) attach to tissue culture cells to a much lesser extent than do pilated, type 2 organisms of the same strain. Trypsin treatment of either pilated (type 2) or nonpilated (type 4
*
) gonococci markedly reduces the attachment-ingestion of these organisms with leukocytes, but the same trypsin treatment does not depilate the type 2 organisms nor visibly alter the morphology of their pili. Similar reductions in association with leukocytes are found if the gonococci are pretreated with chymotrypsin, heat, or glutaraldehyde. High levels of association between gonococci and leukocytes are reestablished if the trypsin or chymotrypsin-treated organisms are reincubated in protease-free medium. These data suggest that interactions between gonococci and human neutrophils are mediated through surface characteristics of the bacteria, different from those which influence attachment of the organisms to tissue culture cells. In the latter instance, pili appear to positively influence gonococcal attachment, whereas in the former a nonpilus bacterial cell wall nonpilus protein is probably the major determiner in the interaction between leukocytes and gonococci.
Studies on Gonococcus Infection VI. Electron Microscopic Study on In Vitro Phagocytosis of Gonococci by Human Leukocytes
Authors: Swanson John , Zeligs Barbara
Published: January 2020

The ingestion of
Neisseria gonorrhoeae
by isolated human leukocytes in vitro has been studied by electron microscopy. Use of the modified critical-point drying method allows clear visualization of progressive ingestion of both pilated and nonpilated gonococci by leukocytes. Incomplete ingestion of pilated gonococci with protrusion of tangled masses of pili from sites of phagocytosis are also found.
Interrelationship Between Serum Beta-Lysin, Lysozyme, and the Antibody-Complement System in Killing
Escherichia coli
Authors: Donaldson David M. , Roberts Robert R. , Larsen Hal S. , Tew John G.
Published: January 2020

The effects of different serum components alone and in conjunction with each other on
Escherichia coli
B were investigated. In general, the viability, turbidity, and electron microscope results were compatible with the following conclusions. The most efficient killing and destruction of
E. coli
B occurred when beta-lysin, lysozyme, and the antibody-complement system functioned in cooperation with each other at the serum concentration in isotonic solutions. The addition of sucrose protected the bacteria from the lethal and lytic action of these agents. Elimination of lysozyme from serum had the least effect on bactericidal activity, even though lysozyme treatment caused the cell wall to separate from the cytoplasmic membrane and caused clear areas to appear in the inner granular layer of the cell wall. Beta-lysin removal had an intermediate effect on the serum bactericidal activity. Beta-lysin treatment caused cell walls to collapse, allowed cytoplasmic contents to leak out of the cells, and stopped the separation of cell wall and cytoplasmic membrane, which normally takes place in 0.5 M sucrose solution. Inactivation of the complement eliminated the serum bactericidal activity against
E. coli
B. After treatment with antibody and complement, the cell walls became thick and indistinct, a portion of the cytoplasmic contents escaped, and patches of the middle layer of the cell wall appeared in freeze-etch preparations. Beta-lysin damaged the cytoplasmic membrane, lysozyme damaged the inner peptidoglycan layer of the cell wall, and the antibody-complement system damaged both the middle lipopolysaccharide layer of the cell wall and the cytoplasmic membrane.
Characterization of Plasmid Deoxyribonucleic Acid from
Neisseria gonorrhoeae
Authors: Mayer Leonard W. , Holmes King K. , Falkow Stanley
Published: January 2020

Five of six independent gonococcal isolates have been found to harbor a plasmid pool of covalently closed-circular deoxyribonucleic acid about 2.4 × 10
6
daltons in size. The plasmid species were 0.5-mol fraction of guanine plus cytosine and comprised 6 to 8% of the total gonococcal deoxyribonucleic acid equivalent, to approximately 24 to 32 copies per cell. There was no apparent correlation between the presence of these plasmid species and the in vitro clonal variation of gonococci associated with the loss of pili.
Urea Utilization by
Leptospira
Authors: Kadis Solomon , Pugh William L.
Published: January 2020

One representative of each of five different pathogenic serotypes of
Leptospira
as well as one saprophytic strain were capable of growing on medium containing urea in place of an ammonium salt as a nitrogen source. Growth of all of the organisms tested on 1% urea was substantial, but only those that exhibited strong urease activity could grow to any appreciable extent on urea at a concentration as high as 2%. Intact urea-grown cells of the pathogenic serotypes tested (grippotyphosa and icterohaemorrhagiae) exhibited urease activity, with the level of activity of the former being considerably greater. No urease could be detected in cells of the saprophytic strain. When the pathogenic leptospires were sonicated or treated with toluene, the urease activity was greatly enhanced. When cultivated on NH
4
Cl, neither intact nor disrupted cells of any of the strains tested exhibited any urease activity. Cells of the grippotyphosa and icterohaemorrhagiae strains exhibited diauxic growth when cultivated in the presence of both NH
4
Cl and urea, whereas only monophasic growth could be detected for the saprophytic test strain. The experimental data on urea utilization and urease activity, when considered in the light of previously reported findings on leptospiral pathology, renal physiology, and the role of urease in other bacterial infections, suggests a significant role for leptospiral urease (in addition to other factors) in determining localization of the organism in the kidney and contributing to the resultant kidney pathology.
Immune Responses in Infections with Coccidia: Macrophage Activity
Authors: Rose M. Elaine
Published: January 2020

Peritoneal exudate cells from chickens immunized with two species of coccidia,
Eimeria tenella
or
Eimeria maxima
, were examined for their capacity to phagocytose stages of the parasite in vitro. True phagocytosis of the sporozoite stage is difficult to estimate because of its ability to invade cells, but may be evaluated by comparison with control suspensions. Peak activity (compared with cells from coccidia-free chickens) was found 3 to 5 weeks after the first inoulum of oocysts of
E. tenella
, and 1 week after the first inoculum of
E. maxima
— times which correspond to the onset of complete immunity to infection. Cells from coccidia-free chickens, in the presence of serum from birds immunized with
E. tenella
, phagocytosed sporozoites of
E. tenella
in a similar manner to cells from immunized birds. The immune serum had both cytophilic and opsonic adherence properties and the latter was species specific (for the two species tested).
Pathogenesis of Human Parainfluenza Type 3 Virus Infection in Hamster Tracheal Organ Culture
Authors: Klein Joel D. , Collier Albert M.
Published: January 2020

Hamster tracheal organ culture was employed as a model for the study of the pathogenesis of human parainfluenza type 3 virus infection. It clearly supported replication of the virus over a 2-week period of time. Infected tracheal explants were examined with light, electron, and immunofluorescence microscopy. They exhibited specific cytopathologic alterations including nuclear swelling and chromatin margination, multinucleated syncytia and binucleated epithelial cells, and fibroblasts and chondrocytes. Focal destruction and denudation of the respiratory epithelium occurred in later stages of infection. Virus was detected in close association with cilia and was observed budding off the unit membrane of epithelial cells.
Rapid Effective Measure of a Humoral Substance(s) Reacting Specifically with
Mycobacterium leprae
Antigens
Authors: Reich Claude V.
Published: January 2020

Leprosy-specific humoral reactants were demonstrated by light scatter. Of 132 lepromatous leprosy sera, 70% gave more extensive reactions than 99% of 100 normal sera.
Cell-Mediated Immune Responses of Preleukemic AKR Mice
Authors: Martig Robert J. , Tribble Jack L.
Published: January 2020

Splenic lymphocytes from preleukemic AKR mice are capable of participating in various cell-mediated immune responses. Spleen cells from AKR mice aged 1 to 10 months produced a significant graft-versus-host reaction when injected into 8-day-old AKR × C57Bl/6 F
1
hybrids. Splenic lymphocytes from similarly aged mice were also capable of responding to allogenic stimulation in a mixed lymphocyte reaction. AKR mice aged 1 to 10 months developed a contact sensitivity response to picryl chloride. It was concluded that mice of this high-leukemic strain have a competent cell-mediated immune system and there is no depression of immunity during the preleukemic period.
Enhancement of Primary Antigen-Specific Resistance in Infant Mice with Divinyl Ether-Maleic Anhydride
Authors: Richmond J. Y. , Campbell C. H.
Published: January 2020

The early response of infant mice to foot-and-mouth disease viral antigens, measured by greater resistance and increased serum-neutralizing antibody, was enhanced by divinyl ether-maleic anhydride (DVE/MA). Preparations of known antigen concentration were used to study various parameters influencing this enhancement. Resistance and antibody levels were increased when DVE/MA was administered with aqueous or oil-emulsified antigens, whether given separately or mixed with the antigens, but was dependent on the dose and route of the DVE/MA and antigen. Enhanced resistance developed rapidly, was antigen-specific, and may have been related to the level of neutralizing antibody.
Persistent Infection of Mice with the Virus of Lymphocytic Choriomeningitis: Virus-Specific Immunological Tolerance
Authors: Cihak Josef , Lehmann-Grube Fritz
Published: January 2020

Lymphocytic choriomeningitis (LCM) virus-infected culture cells as targets were markedly reduced in numbers when incubated in vitro with spleen cells from LCM virus-immune mice, even if the cells were taken months after a subcutaneous immunizing infection of the donor animal. Spleen cells from mice persistently infected with LCM virus had no effect on target cells. Also, mitomycin C-blocked LCM virus-infected culture cells stimulated the incorporation of radiolabeled thymidine into spleen cells from LCM virus-immune mice. No stimulation was observed with spleen cells from LCM virus carrier mice. It was concluded that cell-mediated immunity directed against LCM virion surface antigen(s) is absent in LCM virus carrier mice.
Bactericidal Activity of Metal-Mediated Peroxide-Ascorbate Systems
Authors: Drath David B. , Karnovsky Manfred L.
Published: January 2020

Model systems containing ascorbate, hydrogen peroxide, and divalent copper or cobalt have been shown to possess marked bactericidal activity. At equivalent concentrations, copper-containing systems were more bactericidal than the corresponding mixtures containing cobalt. Cobalt at concentrations below 10
−4
M did not appreciably augment microbicidal activity, whereas systems containing copper at concentrations as low as 5 × 10
−6
M were still capable of causing some bacterial death. Manganese was inactive. None of these systems was as potent as the well known myeloperoxidase-peroxide-halide system. The mechanisms of action of these systems are not as yet clear. The possibility that they function through the generation of superoxide (O
2
−
), hydroxyl radical (OH·), or other free radicals was explored through the use of superoxide dismutase and several free radical scavengers. It seems likely at present that the two active metal-mediated systems function via separate mechanisms. The copper system acts with dehydroascorbate, whereas the cobalt system does not. Activity in the cobalt system appears to depend upon the generation of free radicals.
Experimental Cholera in Chinchillas: the Immune Response in Serum and Intestinal Secretions to
Vibrio cholerae
and Cholera Toxin
Authors: Blachman Uzy , Graboff S. R. , Haag G. E. , Gottfeld E. , Pickett M. J.
Published: January 2020

The immune response to
Vibrio cholerae
and cholera toxin was studied in chinchillas inoculated intra-intestinally with 10
8
viable
V. cholerae
596B. Sera and intestinal fluids were collected from animals on days 1, 2, 3, 5, 7, 10, 14, 30, and 60 postinoculation, and antibodies were quantified by various methods. When radiovibriolytic and radiotoxin precipitin tests were used, a significant (fourfold) rise in both antibacterial and antitoxic titers was detected in intestinal fluids on the 2nd day of infection. In contrast, a significant rise in serum antibodies occurred between days 3 and 5. Since the acute phase of the chinchilla disease lasts 1 to 3 days, recovery coincided with rise in intestinal antibody but not with rise in serum antibody. Our results indicate that both antibacterial and antitoxic mechanisms are operative in chinchilla cholera and that the initial and crucial immune response is local in nature.
Endotoxin-Altering Activity of Plasma Does Not Affect Antigenicity of Native Protoplasmic Polysaccharide
Authors: Rudbach Jon A. , Luoma M. Kay
Published: January 2020

The capacity to precipitate quantitatively with homologous antiserum of native protoplasmic polysaccharide from
Escherichia coli
was not reduced by incubation in human plasma; it was reduced with the immunochemically related lipopolysaccharide.
Some Immunochemical Properties of Dextransucrase and Invertase from
Streptococcus mutans
Authors: Fukui Kazuhiro , Fukui Yoshio , Moriyama Takafumi
Published: January 2020

Dextransucrase and invertase of some strains of
Streptococcus mutans
were examined by immunodiffusion with antisera against enzymes purified from strain HS-6 (Bratthall's serotype
a
). Both antisera cross-reacted with crude enzyme preparations from the other serotype
a
(strains HS-1 and AHT) and
d
organisms (strains KIR, OMZ176, and OMZ65) but not with those from serotype
b
(strains FA-1 and BHT) or
c
organisms (strains GS-5, Ingbritt, and NCTC 10449). Based upon the antiserum used, the orders of antigenic similarity of the cross-reacting enzymes to the HS-6 enzymes were HS-6 > HS-1 > AHT = KIR = OMZ176 = OMZ65 for dextransucrase and HS-6 = HS-1 > AHT = KIR = OMZ176 = OMZ65 for invertase. It was found that the enzymes from serotype
a
organisms were not always antigenically homogeneous, as seen between strains HS-6, HS-1, or AHT for dextransucrase, and between the HS group and strain AHT for invertase. Antiserum against the HS-6 dextransucrase markedly inhibited the heterologous dextransucrases of serotype
a
organisms with the exception of strain HS-1 and
d
organisms, with or without the addition of dextran.
Production of Hemolysin and Bacteriolysin in a Synthetic Medium by
Streptococcus faecalis
var.
zymogenes
Authors: Appelbaum Benjamin , Zimmerman Leonard N.
Published: January 2020

A synthetic medium has been developed in which
Streptococcus faecalis
var.
zymogenes
X-14 elaborates a lysin. The medium consists of 18 amino acids, lactose, six vitamins, adenine, guanine, uracil, and six salts. Glucose, and K
2
HPO
4
in excess of 0.5% (wt/vol), were inhibitory to lysin production; increasing concentrations of
l
-arginine-hydrochloride gave increasing yields of lytic activity.
Protection Against Gram-Negative Infections with Antiserum to Lipid A from
Salmonella minnesota
R595
Authors: Mullan Noel A. , Newsome Peter M. , Cunnington Peter G. , Palmer Geoff H. , Wilson Margaret E.
Published: January 2020

The ability of antisera to lipid A, induced in rabbits by immunization with lipid A complexed to various carriers, to protect mice against gram-negative infection and to inhibit the fluid loss caused by an enteropathogenic strain of
Escherichia coli
in the piglet ligated gut was investigated. No significant protection was obtained in either case, although passive hemolysis and quantitative precipitation tests showed the presence of antilipid A antibodies in the sera. Fluorescent antibody studies suggest that the lipid A is in a cryptic position on the surface of smooth strains of gram-negative bacteria.
Antiviral Activity of an Ether-Extracted Nonviable Preparation of
Brucella abortus
Authors: Youngner J.S. , Keleti G. , Feingold D. S.
Published: January 2020

Extraction of living
Brucella abortus
(strain 456) with aqueous ether yielded a nonviable, insoluble residue (Bru-Pel). When injected into mice, Bru-Pel was an effective, nontoxic interferon stimulus. Mice pretreated with Bru-Pel were protected against challenge with otherwise lethal doses of Semliki Forest virus. Significant protection was afforded when Bru-Pel was given as many as 7 days before virus challenge. Evidence is presented dealing with the complex nature of Bru-Pel and with the possibility that the antiviral activity of Bru-Pel may be associated not only with the production of interferon, but with a general increase in the level of nonspecific resistance in animals.
Experimental Intra-Abdominal Abscesses in Rats: Development of an Experimental Model
Authors: Weinstein William M. , Onderdonk Andrew B. , Bartlett John G. , Gorbach Sherwood L.
Published: January 2020

An animal model has been developed to study the evolution of intra-abdominal abscesses. Gelatin capsules containing pooled colonic contents and barium sulfate were prepared in an anaerobic chamber and implanted into the pelvic region of Wistar rats. The natural course of the ensuing disease was studied in various groups according to the source of the inoculum and sex of the recipient. Colonic contents derived from rats fed a grain diet produced a highly lethal disease with an 80% mortality rate for males and 100% for females. Most deaths occurred within 3 days of implantation, and autopsies showed generalized peritonitis. The addition of blood to the inoculum caused a rapidly fatal peritonitis in all animals. With an inoculum derived from meat-fed rats implanted in male recipients, there was a biphasic disease. Initially, there was peritonitis associated with 43% mortality. All animals that survived this acute period developed discrete intra-abdominal abscesses by the seventh postoperative day. The latter stage was characterized by an indolent course and progressive enlargement of abscesses.
Binding of Cholera Toxin to Mucins and Inhibition by Gastric Mucin
Authors: Strombeck Donald R. , Harrold Doris
Published: January 2020

The effects of mucin on cholera toxin induced intestinal secretion was studied in the rat small intestine. Gastric mucin inhibited secretion when premixed with cholera toxin on an equal dry-weight basis. Neither salivary nor intestinal mucin inhibited the toxin's action in the intestine. Inhibition by gastric mucin was not reversed by a mucolytic agent or by hexoses or agents that bind hexoses. Plasma and serum did not inhibit the effects of cholera toxin in the intestine. Choleragen was labeled with
14
C and its binding to mucins and ganglioside was studied. Gastric mucin was shown to bind to choleragen, but less binding was observed when choleragen was dissociated into subunits by acid pH. Salivary and intestinal mucins bound intact choleragen but not the subunits at acid pH. Salivary mucin binding was reversed by
N
-acetyl neuraminic acid and neuraminidase. Ganglioside bound choleragen in both the intact and dissociated forms. Binding to the dissociated form was reversed by wheat germ agglutinin. Gastric mucin and ganglioside competed for binding to choleragen with the binding of intact choleragen greater for ganglioside and the affinity of the subunits greater for gastric mucin. Electrophoresis of labeled choleragen showed uniform labeling of the subunits dissociated by acid pH, but a major part of cholera toxin was found not to be labeled when fractionated with sodium dodecyl sulfate and 2-mercaptoethanol.
Vitamin E Protects Mice Against
Diplococcus pneumoniae
Type I Infection
Authors: Heinzerling Rollin H. , Tengerdy Robert P. , Wick Linda L. , Lueker David C.
Published: January 2020

Vitamin E protects nonimmunized and immunized mice against fatal
Diplococcus pneumoniae
type I (DpI) infection. A dietary supplementation of 180 mg of
dl
-α-tocopheryl acetate per kg of diet increased survival of nonimmunized mice from 20 to 80% when challenged with 20 organisms, and of mice immunized with 0.5 ng of DpI polysaccharide from 15 to 70% when challenged with 20,000 organisms. The phagocytic index of immunized mice was four times higher in the 180-mg vitamin E group than in the control group. Both the survival and phagocytic index revealed a biphasic dose response, indicating a cause-effect relationship between phagocytosis and survival. Vitamin E also significantly increased the rate of carbon clearance from blood, indicating a general increase in phagocytic activity. The data indicated that increased macrophage activity probably aided by increased antibody production was the principal reason for increased protection.
Immune Response to
Mycobacterium leprae
: Plaque-Forming Cells in Mice
Authors: Navalkar R. G. , Patel P. J. , Dalvi Rekha R. , Levy L.
Published: January 2020

Intravenous immunization with a cell extract of
Mycobacterium leprae
produced a primary immune response of considerable magnitude, followed by an equally large response after secondary stimulation, as measured by assay of plaque-forming cells (PFC). Infection with
M. leprae
or immunization with cell extract by the footpad route produced a lower level of response than that seen in the intravenous group. Identical patterns of response, although not of the same magnitude, were observed after both primary and secondary challenges in the two footpad groups, one infected with viable
M. leprae
and the other immunized with
M. leprae
cell extract. The secondary response after a booster dose to all these groups appeared to be an enhanced immunoglobulin M response. Control studies confirmed that the immune response was a direct result of the host-parasite interaction and that the PFC observed resulted from stimulation of antibody-forming cells by antigens of
M. leprae.
The similarity in time of appearance of peak PFC levels in the two footpad groups may be attributed to the live challenge passing through a latent phase. Alternatively, the challenge is known to contain a large proportion on nonviable cells, and it may also contain soluble
M. leprae
antigens. Studies of the cross-reactivity of the antigens have extended previous observations on antigens shared between
M. leprae
and other mycobacterial species. Use of the two antigen-containing fractions of the
M. leprae
cell extract has suggested that one of the fractions contains some shared antigens, whereas the other has an antigen specific to
M. leprae.
Serological Relationships Among Feline Caliciviruses
Authors: Povey R. C.
Published: January 2020

A total of 46 strains of feline calicivirus isolates from the United Kingdom, United States, Australia, and New Zealand were used in an investigation of their serological relationships based on the serum neutralization test. Although demonstrable antigenic variation exists between these isolates, it is shown that significant in vitro cross-activity exists between all these isolates to greater or lesser extent. All isolates tested may be regarded as serological variants of a single serotype of feline calicivirus. It is postulated that this relationship would provide for considerable cross-protection during successive exposures of cats to various feline caliciviruses.
Protein Synthesis by
Treponema pallidum
Extracted from Infected Rabbit Tissue
Authors: Baseman Joel B. , Hayes Nancy S.
Published: January 2020

Virulent
Treponema pallidum
organisms, extracted from infected rabbit testes, incorporated amino acids into protein. A temperature of 34 C and a pH of 7.6 were optimal for protein synthesis, which was linear during in vitro incubation for 24 h. Selective inhibition of protein synthesis by erythromycin as judged by the incorporation of radiolabeled amino acids and radioautography demonstrated that treponemes were actively synthesizing proteins. Since addition of various sera and ultrafiltrates to the basal incubation mixture did not stimulate the level of protein synthesis, it was uncertain whether treponemes synthesized protein at a maximal or endogenous rate. Based upon the size of the unlabeled amino acid pool contained in infected testicular extract, it appeared that virulent treponemes utilized the majority of amino acids for protein synthesis but at varying efficiency.