bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Certain Cations (Fe, Zn, Mg, and Ca) on Bacterial Endotoxins
Authors: Šourek Jiří , Tichý Miloň , Levin Jack
Published: January 2020

The natural occurrence of cations Fe, Zn, Mg, and Ca in the lipopolysaccharide (LPS) of both the S and R forms of
Shigella dysenteriae
1 was studied. LPS preparations were obtained either by phenol-water extraction (according to the method of Westphal et al., Z. Naturforsch.
7b
:148-155, 1952) or by extraction of cells with hypertonic sodium chloride-sodium citrate (according to the method of Raynaud and Digeon, C. R. Acad. Sci. (Paris)
229
:564-566, 1949), with subsequent chromatographic purification on Sephadex G200 and Sepharose 4B columns. The cation in highest concentration in the Westphal extract was Mg
2+
(as much as 30 μg/mg), and the lowest one was Fe (ca. 0.10 μg/mg). In LPS of the Raynaud type, the cation in highest concentration was Ca
2+
(as much as 13 μg/mg), and the lowest one was Fe (ca. 0.10 μg/mg). The effects of increasing and decreasing the concentrations of cations (Fe, Zn, Mg, Ca) upon the biological activity of the endotoxins was evaluated by using toxicity in mice and the
Limulus
test. It appeared that increased concentrations of Fe (chiefly of Fe
3+
) decreased the toxicity of the R form of LPS, whereas Mg
2+
decreased the toxicity of the S form. After prolonged dialysis of LPS preparations against deionized water, there was no consistent relationship between toxicity as determined in white mice and with the
Limulus
test.
Specific binding of staphylococcal alpha-toxin to isolated rabbit vagus nerves in vitro
Authors: Szmigielski S , Harshman S
Published: January 2020

The binding of staphylococcal [125I]alpha-toxin to rabbit vagus nerves in vitro was a saturable process. The radiolabeled alpha-toxin binding was reduced by the coaddition of added navive alpha-toxin, indicating that the binding is specific. Sucrose gradient analysis of detergent-extracted complexes of [125I]alpha-toxin-rabbit vagus nerves showed both high and low S-value peaks analogous to those observed with similarly treated alpha-toxin-rabbit erythrocyte preparations (P. Cassidy and S. Harshman, Biochemistry, in press).
Cytotoxic activity of Aeromonas hydrophila
Authors: Donta S T , Haddow A D
Published: January 2020

Most strains of Aeromonas hydrophila tested demonstrated cytotoxic activity on several tissue-cultured cell lines. The cytotoxin is heat-labile, non-dialyzable, and immunologically distinct from that of Shigella dysenteriae and Clostridium perfringens. None of the aeromonas isolates was found to be enterotoxigenic by either tissue culture or rabbit ileal loop assays.
Cellular Immune Response to Cytomegalovirus Infection After Renal Transplantation
Authors: Linnemann Calvin C. , Kauffman Carol A. , First M. Roy , Schiff Gilbert M. , Phair John P.
Published: January 2020

A prospective study of 15 patients who received renal transplants defined the effect of renal transplantation on the cellular immune response to cytomegalovirus infection. Of 15 patients, 14 developed cytomegalovirus infection, usually in the first 2 months after transplantation, and all infections were accompanied by a normal humoral immune response. After the initiation of immunosuppressive therapy and transplantation, there was a general depression of lymphocyte transformation, as reflected in the response to phytohemagglutinin, accompanied by a specific defect in cellular immunity, as indicated by lymphocyte transformation to cytomegalovirus antigen. Eleven patients had cellular immunity to cytomegalovirus before transplantation, and all of these became negative in the first month after transplantation. In subsequent months, only 6 of the 14 study patients with cytomegalovirus infection developed specific cellular immune responses to cytomegalovirus. This occurred most often in patients who had severe febrile illnesses in association with infection. The specific cellular immune response which developed in the posttransplant period did not persist in three of the patients. This study demonstrates the dissociation of the humoral and cellular immune response to cytomegalovirus infection in renal transplant patients and indicates the importance of the loss of cellular immunity in the appearance of infection. Previously infected patients lost their cell-mediated immunity and had reactivation infections despite the presence of serum antibody.
Radiolabeling of Treponema pallidum (Nichols virulent strain) in vitro with precursors for protein and RNA biosynthesis
Authors: Sandok P L , Jenkin H M
Published: January 2020

We observed uptake of [U-14C]serine, U-14C-labeled amino acid hydrolysates, and [2-14C]uracil by virulent Treponema pallidum in vitro for at least 96 h. No uptake of [2-14C]thymine, [1-14C]pyruvate, [U-14C]pyruvate, and [2-14C]uridine was detected. Treponemal protein and RNA biosynthetic activity was identified by erythromycin inhibition of amino acid and uracil uptake. Radioactivity due to uptake of radiolabeled amino acids by residual testicular cells in the cultures remained at background levels regardless of the presence or absence of cycloheximide. Accumulation of the radiolabeled substrates by T. pallidum proceeded at a linear rate for 48 to 96 h during incubation in vitro. The longevity of substrate uptake using the system of incubation described will facilitate future studies on the metabolism of the microorganism to help determine essential growth factors and environmental conditions for multiplication of T. pallidum in vitro.
Mannose Binding and Epithelial Cell Adherence of
Escherichia coli
Authors: Ofek Itzhak , Beachey Edwin H.
Published: January 2020

The mannose-binding activity of several isolates of
Escherichia coli
was monitored by aggregometry with mannan-containing yeast cells. The velocity of yeast cell aggregation was found to correlate with the ability of the organisms to adhere to human epithelial cells. Mannose or its derivatives specifically inhibited or reversed epithelial cell adherence and yeast cell aggregation. Most of the adherent bacteria could be displaced within 30 min from the epithelial cells with methyl α-
d
-mannopyranoside, but not with other sugars tested. Cultures of
E. coli
were fractionated into nonadherent and adherent populations by adsorption with epithelial cells followed by elution of the adherent bacteria with methyl α-
d
-mannopyranoside. When the methyl α-
d
-mannopyranoside-displaced organisms were washed free of the sugar, they exhibited a high degree of mannose-binding activity and were heavily piliated. In contrast, the nonadherent fraction of organisms lacked detectable mannose-binding activity and were devoid of pili. Our results suggest that the binding activity of a mannose-specific lectin on the surface of
E. coli
can be quantitated directly on intact organisms, and the observed variations in the amount of mannose-binding activity among human isolates accounts for the variation in adherence of the organisms to mannose residues on epithelial cells.
Comparison of the histamine hypersensitivity and the Limulus amoebocyte lysate tests for endotoxin activity
Authors: Munoz J J , Bergman R K , Robbins K E
Published: January 2020

The histamine hypersensitivity test and the Limulus amoebocyte lysate test were compared for their effectiveness to quantitate endotoxin activity. The two tests compared favorably in all the trials, except with a sample of endotoxin from Brucella abortus that gave a positive Limulus amoebocyte lysate test at a concentration of 0.001 microgram, while failing to sensitize mice to histamine at a dose of 16 microgram per mouse. The Limulus amoebocyte lysate test was more sensitive than the histamine hypersensitivity test.
Delayed-type hypersensitivity responses in infected mice elicited by cytoplasmic fractions of Cryptococcus neoformans
Authors: Hay R J , Reiss E
Published: January 2020

Four subcellular fractions of Cryptococcus neoformans prepared by differential centrifugation of disrupted whole yeast and a 3-day culture filtrate were examined for their ability to elicit delayed-type hypersensitivity in sensitized animals. The methods used to detect sensitization were (i) the footpad swelling test and inhibition of peritoneal macrophage migration in mice and (ii) skin testing in guinea pigs. Two entities, the post-mitochondrial supernatant and the culture filtrate, showed considerable activity in the footpad test, with 26- and 30-microliter 24-h swellings, respectively, at 6 weeks after infection. With the latter there was interference from a strong antibody-mediated 4-h skin reaction. The post-mitochondrial supernatant produced strong delayed-type hypersensitivity in guinea pigs at a dose of 69 microgram, and there was no demonstrable cross-reactivity in animals sensitized with heterologous fungi. The footpad swelling in mice correlated well with the macrophage migration inhibition test, with 71% inhibition in mice infected subcutaneously with C. neoformans at 6 weeks. However, mice infected intravenously developed poorer cell-mediated immunity than the subcutaneously infected mice. The post-mitochondrial supernatant was found to contain detectable amounts of cryptococcal capsular polysaccharide.
Growth of Trypanosoma musculi in cultures of murine spleen cells and analysis of the requirement for supportive spleen cells
Authors: Albright J W , Albright J F
Published: January 2020

Growth of Trypanosoma musculi in vitro has been achieved. The number of parasites increased by more than 1,500-fold in less than 8 days under the most suitable conditions. The rate and magnitude of growth was comparable to that which occurs in inoculated murine hosts. Maximum growth was displayed in cultures composed of RPMI 1640 medium supplemented with fetal calf serum, murine spleen cells, and foreign erythrocytes (sheep). No growth occurred in the absence of spleen cells. The adherent, macrophage-rich population supported parasite growth much better than did the nonadherent population. Parasite growth was excellent in the presence of irradiated spleen cells or of cells from thymectomized, irradiated, bone marrow-reconstituted mice. The important cells appeared to be macrophages. The beneficial effect of sheep erythrocytes probably resulted from preoccupation or stimulation of phagocytes. Soluble substances released by spleen cell cultures promote parasite growth, as was shown by experiments with double-compartment culture vessels. The utility of this culture system for analysis of host immune responses against the trypanosome was demonstrated.
R-factor inheritance and plasmid content in mucoid Pseudomonas aeruginosa
Authors: Markowitz S M , Macrina F L , Phibbs P V
Published: January 2020

Eighteen strains of alginate-producing mucoid Pseudomonas aeruginosa were evaluated with respect to plasmid content and the ability to maintain well-characterized R plasmids. The spontaneous loss of alginate production in these strains varied from 0.01 to 0.7% and was not significantly increased by plasmid curing regimens. Examination of cleared lysates of these strains and their isogenic nonmucoid derivatives by agarose gel electrophoresis failed to reveal plasmid DNA. R-plasmid (P-incompatibility-group) transfer to mucoid P. aeruginosa was unaffected by the presence of the alginate capsule. Maintenance and expression of such plasmids in the mucoid strains were confirmed by agarose gel electrophoresis and by verification of plasmid-linked drug resistance and pilus-specific bacteriophage sensitivity. These studies demonstrate that alginate production does not appear to be plasmid linked and that mucoid P. aeruginosa are capable of receiving and donating certain drug resistance plasmids. Since some of the plasmids used here have been shown to mobilize chromosomal DNA, strains constructed in this study should afford the means for exploring the genetic basis of the mucoid phenotype.
Characterization of mouse peritoneal exudate and associated leukocyte adherence inhibitory activity after intraperitoneal injection of either Bordetella pertussis or Corynebacterium parvum vaccines
Authors: Klein T W , Pross S H , Benjamin W R
Published: January 2020

Bordetella pertussis and Corynebacterium parvum are commonly used immunopotentiating agents. To explore the inflammatory environment induced by these agents, the peritoneal exudate response in mice following intraperitoneal injection of B. pertussis (PV) and C. parvum (CV) vaccines was investigated. The PV-induced exudate isolated by lavage was characterized by an early neutrophil influx followed by enhanced accumulation of mononuclear cells and fluid protein. The CV exudate was principally mononuclear in nature and displayed fewer numbers of cells and less fluid protein. Both vaccines also enhanced the leukocyte adherence inhibitory activity (LAIA) of peritoneal fluid as measured in vitro. The development of exudate LAIA was T lymphocyte independent. A similar LAIA was demonstrated in nonimmune mouse plasma and serum. Exudate fluid and serum LAIA were heat stable and trypsin sensitive. These studies suggest that significant differences exist in the composition of the local tissue environment following PV and CV injection and that exudate LAIA is serum derived. Further studies in this direction should result in a better understanding of the ways in which inflammatory cells and fluid substances affect lymphocyte-macrophage interaction subsequent to adjuvant administration.
Ultrastructural studies on the interaction between Salmonella typhimurium 395 M and HeLa cells
Authors: Kihlström E , Latkovic S
Published: January 2020

The interaction of Salmonella typhimurium 395 MS and its rough Rd-mutant 395 MR10 with HeLa cells was studied by transmission and scanning electron microscopy. The bacteria attached to central as well as more marginal positions of the HeLa cell surface. Bacteria associated preferentially to HeLa cells with a relatively low number of microvilli, in which they often were entangled. Bacteria attached to the cell border were sometimes surrounded by membrane folds, possibly as a response to their attachment. Infected cells had longer and more slender microvilli compared with noninfected cells. Some parts of the attached bacteria were in close contact with the HeLa cell membrane, whereas other parts were separated from the latter by a gap. Bacteria adhered preferentially to microvilli without obvious membrane damage. Most of the intracellular bacteria were surrounded by a membrane, often appearing as a vacuole, which sometimes contained more than one bacterium. Intracellular bacteria seemed to be morphologically intact. We propose that S. typhimurium enter HeLa cells by a process of phagocytosis.
Proteolytic activity of Candida albicans: action on human salivary proteins
Authors: Germaine G R , Tellefson L M , Johnson G L
Published: January 2020

The susceptibility of human salivary proteins to degradation by Candida albicans was studied. The organism was cultivated in either whole-salivary supernatant or parotid fluid, both of which were supplemented with glucose (0.1%). The culture pH's were at, or above, neutrality. After growth, the culture supernatant solutions were examined by polyacrylamide gel electrophoresis for alterations in their profiles of salivary proteins. No evidence of proteolysis of whole-saliva or parotid fluid proteins was found. Salivary proteins, however, are susceptible to degradation by preparations of C. albicans protease. Candida protease was incubated with parotid fluid adjusted to several pH values. After incubation the reaction mixtures were subjected to polyacrylamide gel electrophoresis. Extensive degradation of parotid proteins was found at pH 4, very slight proteolysis at pH 5, and no degradation at pH 6 or 7. No selectivity in proteolysis of the several parotid proteins was noted. These results indicate that C. albicans protease is strictly dependent upon low (ca. 4) pH for activity on salivary proteins. Furthermore, it is suggested that due to the pH requirements of the enzyme, it is unlikely to be of major significance to the pathogenesis of Candida-induced oral inflammatory lesions.
Characterization of anemia induced by avian osteopetrosis virus
Authors: Paterson R W , Smith R E
Published: January 2020

Chickens infected intravenously at 8 days after hatching with an avian osteopetrosis virus developed a severe, progressive anemia in the absence of osteopetrosis. The anemia was characterized as a pancytopenia, in which erythrocytes, granulocytes, and thrombocytes decreased concomitantly. Serum bilirubin levels were normal, whereas erythrocytes from infected chickens demonstrated a slightly elevated osmotic fragility. A negative Coombs test indicated that there was no evidence for erythrocyte-bound antibody. Erythrocytes from infected animals had slightly decreased 51Cr-labeled erythrocyte survival time when compared with normal. Examination of marrow histological preparations, together with ferrokinetic studies with 59Fe, indicated that marrow failure occurred during the acute phase of the anemia. Circulating virus was present during the development and acute phases of the anemia, but disappeared during the recovery phase of the disease. Neutralizing antibody appeared after the disappearance of circulating virus. It is concluded that virus infection induced both marrow failure (aplastic crisis) and decreased erythrocyte survival.
Interactions between immune cells and antibody in protection from fatal Sindbis virus encephalitis
Authors: Hirsch R L , Griffin D E , Johnson R T
Published: January 2020

Transfer of anti-Sindbis virus serum, obtained from peripherally inoculated donors, protected mice from an otherwise fatal intracerebral infection with neuroadapted Sindbis virus (NSV). F(ab)'2 preparations of serum were not protective, indicating that the Fc piece of immunoglobulin G was important. Complement-depleted animals were protected with anti-NSV serum, ruling out as essential the complement-fixing function of the Fc piece. The presence of protective antibody correlated with the ability of serum to inhibit T-cell cytotoxicity. However, experiments using athymic nude mice showed that T cells played no role in killing the mice since the 50% lethal dose was the same as that in normal BALB/c mice, and that T cells were not required for protection since athymic nude mice were protected with antibody alone. Cyclophosphamide treatment of NSV-infected mice ablated the protective capacity of anti-NSV serum. Therefore, a non-T cell, cyclophosphamide-sensitive cell was required for antibody-mediated protection.
Hemagglutination patterns of enterotoxigenic and enteropathogenic Escherichia coli determined with human, bovine, chicken, and guinea pig erythrocytes in the presence and absence of mannose
Authors: Evans D J , Evans D G , DuPont H L
Published: January 2020

A hemagglutination (HA)-typing system has been developed for the presumptive identification of enterotoxigenic Escherichia coli (ETEC) possessing the colonization factor antigens (CFA) CFA/I or CFA/II. E. coli isolates are grown on CFA agar and tested for mannose-sensitive (MS) or mannose-resistant (MR) HA of human, bovine, chicken, and guinea pig erythrocytes. CFA/I-positive ETEC exhibit MRHA with human, bovine, and chicken erythrocytes, but no HA with guinea pig erythrocytes. CFA/II-positive ETEC produce HA (MRHA) only with bovine and chicken erythrocytes. Common pili appear to be the primary MS-hemagglutinin of E. coli because the prototype strain K-12 exhibits HA (MSHA) with all but bovine erythrocytes. However, only 6.6% (23 of 351) of E. coli belonging to the classical enteropathogenic E. coli serogroups (EPEC) possessed the same HA pattern as strain K-12; 42% of the EPEC cultures (146 of 351) were similar to K-12 in producing MSHA with chicken and guinea pig erythrocytes and no HA with bovine erythrocytes, but different in that these produced either no HA or MRHA with human erythrocytes. These EPEC-associated HA patterns were assigned to a separate category, termed HA type III. Non-EPEC serogroups associated with sporadic diarrhea (i.e., the facultatively enteropathogenic E. coli, or FEEC) and 41% (19 of 46) of available Salmonella isolates also produced HA type III patterns. This observation is of considerable interest because many FEEC possess somatic antigens cross-reactive with Salmonella. Although the biochemical basis for this result has not been established, the data reported herein suggest a relationship between the HA type III phenotype and virulence (enteropathogenicity) in both the EPEC and FEEC serogroups. We propose that HA typing be used in conjunction with serotyping of E. coli to determine the degree of association of HA type III E. coli with sporadic diarrhea in infants and young children.
Inhibition of in vitro proliferative responses of human lymphocytes by rimantadine hydrochloride
Authors: Koff W C , Peavy D L , Knight V
Published: January 2020

Rimantadine hydrochloride (alpha-methyl-1-adamantanemethylamine hydrochloride) inhibits the in vitro proliferative response of human peripheral blood lymphocytes to mitogenic and antigenic stimulation. Addition of drug (25 micrograms/ml) at the initiation of 5-day cultures suppressed the responses to phytohemagglutinin, pokeweed mitogen, and concanavalin A by 25, 65, and 90%, respectively. Similarly, responses to streptokinase-streptodornase, tetanus toxoid, and A2/Aichi influenza vaccine were significantly inhibited at concentrations as low as 10 micrograms of rimantadine per ml. Viability studies on 5-day cultures using trypan blue exclusion showed no significant difference between drug-treated and untreated controls. Furthermore, addition of drug on day 3 of 8-day cultures, at a time when the majority of cells had undergone blastogenesis, greatly suppressed the responses to these mitogens. These studies suggest that, in addition to its antiviral action, rimantadine interferes with the generation of cellular immune responses.
Variable infection of Vero cells and homologous interference after co-cultivation with HeLa cells with persistent defective infection by Edmonston measles virus
Authors: Rustigian R , Winston S H , Darlington R W
Published: January 2020

The HeLa subline K11A-HG-1 (line of HeLa cells persistently infected with Edomonston measles virus but containing little or no transmissible infectious virus) was co-cultivated with Vero cells. Focal syncytia were formed containing measles antigen and accumulations of nucleocapsid-like structures with no detectable production of transmissible infectious virus or positive hemadsorption. The infection aborted between 2 and 3 weeks after preparation of co-cultures. Upon subculture of co-cultures, occasionally complete infections (progressive syncytial degeneration, hemadsorption, and production of transmissible infectious virus) appeared. A linear dose response curve for nontransmissible infection was obtained along with evidence that measles antigen had to be present on the surface of K11A-HG-1 cells for their infectivity for Vero cells. The basis for initiation of Vero cell infection by living K11A-HG-1 cells, but not by nonviable intact K11A-HG-1 cells killed by a virus-preserving technique, nor by disrupted K11A-HG-1 cells, is, at present, a matter of speculation. However, several lines of evidence were obtained which suggested that subsequent development of delayed variable transmissible Vero cell infection occurred because of a type of viral interference, including the presence of an inhibitor in K11A-HG-1 cultures, the bulk of which was cell-associated.
Immunoregulatory Responses in Experimental Disseminated Histoplasmosis: Lymphoid Organ Histopathology and Serological Studies
Authors: Artz Ronald P. , Bullock Ward E.
Published: January 2020

To study immunoregulatory mechanisms in systemic histoplasmosis, a highly reproducible model of infection was established in C3H/Anf mice. Intravenous inoculation of 6- to 8-week-old mice with from 5 × 10
5
to 10 × 10
5
cells of yeast-phase
Histoplasma capsulatum
strain G-217B produced disseminated infection that resolved over an 8-week period without therapeutic intervention. Serological studies demonstrated complement-fixing antibody production to yeast- and mycelial-phase antigens of
H. capsulatum
. Complement-fixing antibody to the former was detected at week 1, and it peaked at week 3 and declined thereafter. Complement-fixing antibody to mycelial-phase antigen(s) appeared later (week 3) and did not peak until week 18. Grossly, the spleens of infected mice were enlarged from three to four times normal size during peak infection, whereas the thymuses were markedly involuted. Conversely, at week 8 the average spleen size was considerably smaller and the thymic mass was increased relative to the mass at week 3. Histopathologically, the paracortical regions of lymph nodes and the white pulp (periarteriolar lymphocyte sheaths) and marginal zones of the spleen were heavily infiltrated by granulomata at week 1. By week 8, the infiltrates in these areas had largely resolved. Thymocytes were severely depleted from the cortical lobules of the thymus at week 1; however, thymic cellularity was restored by week 8. These reciprocal changes in cellularity of the thymus and spleen during active infection may be of importance with reference to the disturbances of immunoregulation that we have observed in
Histoplasma
-infected mice.
Linkage Analyses of Extracellular Glucans from
Streptococcus sanguis
and
Streptococcus mitior
Authors: Freedman M. , Birkhed D. , Coykendall A. , Rizzo D.
Published: January 2020

Similar α-(1→6) linkage-rich, soluble, extracellular glucans have been isolated from six strains of two genetically distinct groups of
Streptococcus sanguis
and three strains of
Streptococcus mitior.
Influence of Malaria Infection on the Elaboration of Soluble Mediators by Adherent Mononuclear Cells
Authors: Wyler David J. , Oppenheim Joost J. , Koontz Louis C.
Published: January 2020

Malaria results in two seemingly paradoxical perturbations of the immune response: polyclonal B-cell activation and immunosuppression. To determine what immunoregulatory role mediators secreted by adherent cells might play in these alterations, we cultured adherent cells from uninfected mice and from mice at different times during infection with
Plasmodium berghei
or
P. yoelii.
Culture supernatants obtained from these cells were tested for their ability to enhance the in vitro proliferative responses of thymocytes to suboptimal concentrations of concanavalin A or to inhibit the mitogen-stimulated proliferation of normal spleen cells. Supernatants obtained from adherent cells of mice early in infection (days 1 to 3) contained significantly elevated levels of enhancing activity which on Bio-Gel P-100 chromatography resembled lymphocyte-activating factor. Later in infection (days 4 and 5), these supernatants contained inhibitory activity. Normal adherent cells, when cocultivated in vitro with parasitized erythrocytes, ingested parasite debris and were stimulated to produce the enhancing factor. At high parasite/adherent-cell ratios, cells elaborated an inhibitory factor. These findings suggest that during malaria, adherent cells are converted from a nonspecific helper role to a nonspecific suppressor role. This modulation in function may be due to the direct interaction between adherent cells and parasitized erythrocytes.
Effect of Purified
Escherichia coli
Heat-Stable Enterotoxin on Intestinal Cyclic Nucleotide Metabolism and Fluid Secretion
Authors: Giannella Ralph A. , Drake Karen W.
Published: January 2020

Enterotoxigenic
Escherichia coli
cause diarrhea by elaborating two enterotoxins. The large-molecular-weight, heat-labile toxin causes intestinal secretion by stimulating cyclic adenosine 5′-monophosphate production. The mechanism by which the small-molecular-weight, heat-stable enterotoxin induces secretion is unclear. The present study tested the hypothesis that heat-stable enterotoxin induces secretion by altering intestinal cyclic nucleotide concentrations. This was studied in suckling mice by using highly purified
E. coli
heat-stable enterotoxin obtained from a strain pathogenic for humans. At 3 min after administration of this toxin, intestinal cyclic guanosine 5′-monophosphate (GMP) levels were increased 10-fold. Cyclic GMP levels decreased thereafter, but still were greater than control levels at 120 min. Cyclic adenosine 5′-monophosphate levels fell to one-half of control levels at 3 min and remained below control levels for 120 min. When the time course of enterotoxin-induced secretion was compared with changes in cyclic GMP levels, fluid secretion was not evident until 15 to 30 min after enterotoxin administration. Thus, the increase in intestinal cyclic GMP concentration preceded measurable fluid secretion. And finally, administration of the 8-bromo analog of cyclic GMP evoked fluid secretion, the time course of which was similar to that induced by enterotoxin. These, and other data, strongly suggest that
E. coli
heat-stable enterotoxin induces intestinal secretion by increasing intestinal cyclic GMP levels.
Endogenous RD-114 Virus of Cats: Absence of Antibodies to RD-114 Envelope Antigens in Cats Naturally Exposed to Feline Leukemia Virus
Authors: Mandel M. P. , Stephenson J. R. , Hardy W. D. , Essex M.
Published: January 2020

Healthy cats, including those exposed to feline leukemia virus in leukemia cluster households, lack evidence of humoral immunity to virion surface antigens of the endogenous RD-114 virus.
Production of heat-stable enterotoxin by the O128 serogroup of Escherichia coli
Authors: Reis M H , Castro A F , Toledo M R , Trabulsi L R
Published: January 2020

Nine out of 11 Escherichia coli strains belonging to enteropathogenic O128 serogroup were shown to produce heat-stable enterotoxin. This property may be related to the pathogenicity of this serogroup of bacteria.
Inhibitory effect of Pseudomonas aeruginosa on the phagacytic and killing activities of rabbit polymorphonuclear leukocytes: purification and characterization of an inhibitor of polymorphonuclear leukocyte function
Authors: Nonoyama S , Kojo H , Mine Y , Nishida M , Goto S , Kuwahara S
Published: January 2020

A clinically isolated strain of polymorphonuclear leukocyte (PMN)-resistant Pseudomonas was found to produce an extracellular substance (PMN inhibitor) that inhibits the phagocytic and killing activities of PMN. The PMN inhibitor was purified from culture filtrates by precipitation with (NH4)2SO4 and chromatography on phosphocellulose, diethylaminoethyl-cellulose, and Sephadex G-100. The preparation was homogenous as judged by disc gel electrophoresis. The purified PMN inhibitor appeared to be a protein with a molecular weight of approximately 65,000 that was inactivated by heating and by exposure to a proteolytic enzyme.
Depressed mitogen responsiveness of lymphocytes at skin temperature
Authors: Lauwasser M , Shands J W
Published: January 2020

The responsiveness of murine lymphocytes and human peripheral blood lymphocytes to phytohemagglutinin, concanavalin A, pokeweed mitogen, and endotoxin was tested in vitro at 32, 35, and 37 degrees C. The responses at 32 degrees C were delayed and often depressed. Mouse cells responded equally well at 35 and 37 degrees C. Human lymphocytes often responded more rapidly at 37 than at 35 degrees C. Since skin temperature, particularly that of the distal extremities, is usually 32 degrees C or less, a relative deficiency in cell-mediated immunity may exist in these sites. This may be part of the reason for the usual localization of certain infections, such as sporotrichosis, to these coller areas.
Immunological cross-reactivity of oral non-streptococcal bacteria with mammalian tissue
Authors: Stinson M W , Nisengard R J , Pelonero L , Drinnan A J
Published: January 2020

The presence of cross-reacting antigens between oral non-steptococcal bacteria and human and monkey tissue was investigated by indirect immunofluorescence. Rabbit antisera, prepared against 22 oral bacteria, were incubated with cryostatcut sections of heart, skeletal muscle, brain cord, liver, kidney, and skin. A cell wall antigen of Lactobacillus casei was shared with neuroglial brain cells, and an antigenic component of Propionibacterium acnes was shared with kidney glomeruli. Tissue-reactive antibodies were absorbed from the sera with preparations of both the homologous bacterium and tissue fractions.
Neisseria meningitidis infection in mice: influence of iron, variations in virulence among strains, and pathology
Authors: Holbein B E , Jericho K W , Likes G C
Published: January 2020

The influence of iron on Neisseria meningitidis infection in C-57 mice was examined. Iron sulfate, ferric ammonium citrate, and iron sorbitol citrate all proved to be too toxic for use as infection-enhancing agents. Iron dextran displayed an extremely low toxicity, enhanced infection in a dose-dependent manner, and resulted in infection enhancement factors approaching 10(9) for virulent strains of N. meningitidis. Fatal iron dextran-enhanced infection was shown to be reversible by in vivo chelation of iron. Virulent strains of N. meningitidis produced symptoms of infection and pathological lesions in mice both with and without iron pretreatment, but an avirulent strain failed to produce symptoms of infection or pathological lesions, regardless of iron administration. Iron dextran-enhanced infection in mice proved to be a useful model for the examination of virulence of various N. meningitidis strains. All of 9 isolates from clinical disease possessed virulence, whereas only 3 of 10 isolates from carriers possessed virulence, when examined by using this model.
Influence of oil and Tween concentrations on enhanced endotoxin lethality in mice pretreated with emulsified trehalose-6,6'-dimycolate (cord factor)
Authors: Yarkoni E , Rapp H J
Published: January 2020

Susceptibility to the lethal toxicity of endotoxin in mice pretreated with emulsified trehalose-6,6'-dimycolate was enhanced by (i) increasing the oil concentration while keeping the Tween concentration constant; and (ii) decreasing the Tween concentration, while keeping the oil concentration constant.
Effect of sulfolipid I on trehalose-6,6'-dimycolate (cord factor) toxicity and antitumor activity
Authors: Yarkoni E , Goren M B , Rapp H J
Published: January 2020

Emulsified mixtures of sulfolipid I and trehalose-6,6'-dimycolate (cord factor) had tumor-regressive activity comparable to, but less toxic than, emulsified trehalose-6,6'-dimycolate alone.
Leukocyte cytotoxicity in a persistent virus infection: presence of direct cytotoxicity but absence of antibody-dependent cellular cytotoxicity in horses infected with equine infectious anemia virus
Authors: Fujimiya Y , Perryman L E , Crawford T B
Published: January 2020

Antibody-dependent cellular cytotoxicity and direct cytotoxicity assays were performed with equine infectious anemia virus-infected target cells, equine leukocytes, and equine anti-equine infectious anemia virus antibody to determine whether these mechanisms play a role in controlling viral replication in equine infectious anemia. Direct cytotoxicity was observed by using peripheral blood mononuclear cells from 7 of 10 infected horses. Antibody-dependent cellular cytotoxicity was not observed. The antibody-dependent cellular cytotoxicity reaction in horses was then studied by using sheep erythrocytes and trinitrophenylated sheep erythrocytes as target cells. Lysis of these target cells was mediated by neutrophils, monocytes, and lymphocytes. The reaction was activated by antibody of the immunoglobulin G class but not by immunoglobulin G(T). Furthermore, immunoglobulin G(T) efficiently inhibited immunoglobulin G in this function.
Surface protein of a Streptococcus agalactiae isolate
Authors: de Cueninck B J
Published: January 2020

A Streptococcus agalactiae isolate of bovine origin was cultured in broth; log-phase cells were washed and radioiodinated and subsequently extracted at low pH in the presence of a nonionic detergent. A protein antigen was purified from concentrated extract by ultracentrifugation, gel filtration, and ion-exchange chromatography. The molecular weight of the protein was estimated at 31,800. The agglutinogenic character of the protein indicated its localization at the cell surface.
Bound immunoglobulin and foreign antigen in lungs of sudden infant death syndrome victims
Authors: Ackermann W W , Eveland W C , Maverakis N H , Raven C , Golden A
Published: January 2020

Lung sections from 33 infants who died suddenly and unexpectedly and were diagnosed by medical examiners as sudden infant death syndrome (SIDS) gave evidence of bound immunoglobulin G (IgG) when examined by direct fluorescent antibody technique. Ten tissues from appropriate control infants were negative. Specimens containing IgG exhibited no IgA or IgE, but three contained IgM. Sixty-one percent of lung sections with IgG contained either K or lambda antigens; the remainder contained both. The indirect fluorescent antibody technique gave similar results. Blood sera of some individuals in the study which were tested all contained both K and lambda antigens. Fluorescent-labeled immunoglobulin from one SIDS victim stained 7 of 17 SIDS lung sections tested, including his own. Labeled immunoglobulin from three mothers of SIDS victims exhibited differential selectivity in reaction with antigen in lungs of a group of 18 SIDS infants. They did not react with 10 control infant tissues. Various labeled adult sera, cord sera, and serum from an apneic child did not react with the various lungs of SIDS victims in the study.
Deoxyribonucleic acid synthesis, cell cycle progression, and division of Chlamydia-infected HeLa 229 cells
Authors: Bose S K , Liebhaber H
Published: January 2020

The fate of lymphogranuloma venereum strain Chlamydia-infected HeLa 229 cells was examined by determining the rate of deoxyribonucleic acid synthesis and the kinetics of entry into and progression through S phase and by time-lapse cinemicrography. At an input multiplicity of 5 or less, Chlamydia-infected cells showed no inhibition of host deoxyribonucleic acid synthesis or cell cycle progression. Cinemicrography showed division of inclusion-containing cells, with one or both daughters receiving chlamydial inclusions. Analysis of the family trees indicated that the generation times of infected HeLa 229 were not altered relative to those of the uninfected cells.
Toxin-neutralizing effect of antibody against subtilisin-digested tetanus toxin
Authors: Sato H , Ito A , Yamakawa Y , Murata R
Published: January 2020

A form of systemic tetanus with atypical symptoms was observed in mice injected in the left thigh with a mixture of tetanus toxin and antibody produced in guinea pigs against a fragment of toxin obtained from a subtilisin digest of the crystallized toxin. The mice did not show typical symptoms of the local tetanus such as convulsions or spastic paralysis of the injected limb.
Specific absorption of human serum albumin, immunoglobulin A, and immunoglobulin G with selected strains of group A and G streptococci
Authors: Kronvall G , Simmons A , Myhre E B , Jonsson S
Published: January 2020

Five gram-positive bacterial strains were selected for absorption studies of human serum samples. Strain AR1 (group A, M-type 1) and G148 (group G), with strong immunoglobulin G (IgG) binding capacities, and strain AW43 (group A, M-type 60), binding both IgA1 and IgA2, were compared with Staphylococcus aureus Cowan I and with Staphylococcus epidermidis L603. Both AR1 and G148 were capable of completely absorbing out serum IgG. In contrast, S. aureus Cowan I left a fraction unabsorbed, as expected from its known lack of IgG3 binding. Strain AW43 absorbed out all serum IgA, using a 10-microliter bacterial pellet for 20 microliter of serum. Serum IgM levels were slightly reduced by S. aureus Cowan I absorption. On the basis of the experiments, a bacterial mixture was designed consisting of S. aureus Cowan I and group A streptococcus strains AR1 and AW43, with absorption characteristics suitable for use in discriminating between early IgM and late IgG and IgA immune responses in routine serological work. A new type of bacteria-mammalian protein binding was discovered. Human serum albumin was completely absorbed out by strain G148 and to a lesser extent by strain AR1 and AW43. S. aureus Cowan I and S. epidermidis were negative. The binding capacity of G148 for albumin equalled that of Cowan I for IgG. The binding pattern of albumin to the strains was different from those of IgG, IgA, IgM, fibrinogen, haptoglobin, or aggregated beta 2-microglobulin and therefore seems to represent another type of bacterial-mammalian interaction with a specific albumin receptor on the surface of streptococci.
Effect of growth conditions on the formation of extracellular lipoteichoic acid by Streptococcus mutans BHT
Authors: Jacques N A , Hardy L , Knox K W , Wicken A J
Published: January 2020

Streptococcus mutans BHT was grown in a chemostat with glucose limitation and at defined dilution rates and pH values. Lipoteichoic acid was estimated by determining the ability of dilutions of culture fluid to sensitize erythrocytes. The greatest amounts of extracellular lipoteichoic acid were produced by organisms growing at a low dilution rate and at pH 6.0 or 6.5. To enable a more accurate estimation of the total amount of extracellular material, rocket immunoelectrophoresis was employed. These results confirmed that the greatest amounts of reactive material were produced by slow-growing organisms, although there were discrepancies between these results and those obtained by hemagglutination. The extracellular material was fractionated by column chromatography and membrane ultrafiltration to yield a lipoteichoic acid-containing fraction and a presumptive deacylated lipoteichoic acid fraction. The relative proportions detected by rocket immunoelectrophoresis differed with the growth conditions, particularly the dilution rate. Analysis of the phenol-extracted cellular material also indicated the presence of deacylated lipoteichoic acid, although less than in the culture fluid.
In vitro interaction between normal cynolmolgus monkey alveolar macrophages and Legionnaires disease bacteria
Authors: Kishimoto R A , Kastello M D , White J D , Shirey F G , McGann V G , Larson E W , Hedlund K W
Published: January 2020

The interaction between normal cynomolgus monkey alveolar macrophages and Legionnaires disease bacteria was studied by transmission electron microscopy. After ingestion of Legionnaires disease bacteria, the organisms replicated within macrophages and destroyed the phagocytic cell.
Fimbrial hemagglutinin in stationary and shake cultures of Bordetella pertussis
Authors: Arai H , Munoz J J
Published: January 2020

Bordetella pertussis produced hemagglutinin in stationary cultures; in cultures kept under constant shaking, hemagglutinin was found only during the first 48 h of incubation but not after 3 to 5 days. The type of medium had a pronounced effect on production of hemagglutinin. Strain differences in ability to produce hemagglutinin were also detected.
Replication of porcine parvovirus in peripheral blood lymphocytes, monocytes, and peritoneal macrophages
Authors: Paul P S , Mengeling W L , Brown T T
Published: January 2020

Porcine peripheral blood lymphocytes (PBL), peripheral blood monocytes, and peritoneal macrophages were examined for their ability to support porcine parvovirus (PPV) replication. The cell cultures were infected with the NADL-2 strain of PPV at 0.1 multiplicity of infection. PBL cultures were stimulated with the following phytomitogens: phytohemagglutinin M, concanavalin A, and pokeweed mitogen. Unstimulated PBL cultures infected with PPV and uninfected PBL stimulated with phytomitogens served as controls. All cultures were examined daily for PPV-specific immunofluorescence and hemagglutinin. PPV replicated in PBL cultures stimulated with all phytomitogens. Both viral hemagglutinin in culture fluids and nuclear immunofluorescence in cells were detected. In contrast, unstimulated PBL did not support viral replication; however, PPV antigen was detected in the cytoplasm. PPV persisted in unstimulated PBL for 21 days (duration of the experiment) without replication, but replicated each time with the addition of phytohemagglutinin M at 0, 3, 7, 14, and 21 days after infection. Uninfected PBL stimulated with phytomitogens lacked both viral hemagglutinin and immunofluorescence. Simultaneous detection of lymphocyte surface marker and viral antigens in pokeweed mitogen-stimulated PBL revealed that both T and non-T cells (B and null cells) are able to support PPV replication. Peripheral blood monocytes and peritoneal macrophages phagocytized PPV but did not support virus replication.
Immunization with major outer membrane proteins in experimental salmonellosis of mice
Authors: Kuusi N , Nurminen M , Saxen H , Valtonen M , Mäkelä P H
Published: January 2020

Porin (outer membrane protein) preparations extracted from a rough (Rb2) mutant of Salmonella typhimurium proved to be good immunogens in mice and rabbits. The antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques. High titers of both antiporin and antilipopolysaccharide were detected in both species. The rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal Salmonella infection of mice. Absorption of the rabbit antiporin serum with lipopolysaccharide immunosorbent did not change its protective capacity in a passive immunization experiment, suggesting that the antiporin antibody preparations were the active components.
Regulation of mitogen- and antigen-stimulated lymphocyte blastogenesis by prostaglandins
Authors: Muscoplat C C , Klausner D J , Brunner C J , Sloane E D , Johnson D W
Published: January 2020

Exogenously added prostaglandin E1 or E2 inhibited the blastogenic response of Mycobacterium bovis-sensitized bovine peripheral blood lymphocytes stimulated with concanavalin A, phytohemagglutinin, or M. bovis purified protein derivative as measured by [3H]thymidine uptake. The kinetics of the response showed that prostaglandins must be added to lymphocyte cultures within hours after mitogen or antigen addition to achieve maximum suppression of [3H]thymidine uptake. Addition of prostaglandins 24 h after the addition of mitogens or antigens resulted in considerably less suppression, supporting a hypothesis that prostaglandins initiate an early series of events which ultimately control lymphocyte blastogenesis rather than directly inhibit deoxyribonucleic acid synthesis.