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Biomedical subjects

L J Berry

Publications and source records attributed to L J Berry.

At least 37 records · Page 2Linked to original sources
PubMed1979

Sensitization of tolerant mice to cold with a serum factor induced by endotoxin.

Endotoxin-tolerant mice are sensitized to cold (5 degrees C) stress by an injection of 0.4 ml serum collected from zymosan-pretreated mice 2 h after an intravenous (iv) injection of 25 microgram endotoxin. Deaths begin after 6 h and most animals die by 10 h, The factor in serum believed to be responsible for this effect is called glucocorticoid antagonizing factor (GAF). Tolerant mice given 10 microgram endotoxin live for 10 h and two-thirds survive for 24 h. Serum from endotoxin-poisoned conventional mice reduces survival time significantly but not as dramatically as that from zymosan-primed mice. The latter serum, but not endotoxin, causes a rapid drop in the core temperature of tolerant mice housed at 5 degrees C and inhibits the endogenous induction of phosphoenolpyruvate carboxykinase (PEPCK) (EC 4.1.1.32) in tolerant mice exposed for 4--5 h to the cold. An injection of 25 microgram endotoxin does not have this effect on the enzyme. Serum that produces these responses also sensitizes mice to endotoxin lethality and blocks the protection normally afforded against endotoxin by adrenocorticoids.

Adrenal Cortex↗
PubMed1979

Effect of Sindbis birus infection on survival of mice in the cold.

Mice infected with 10(9) plaque-forming units (PFU) of Sindbis virus 9 h prior to exposure to cold (5 degrees C) died more rapidly after entering the new environment than saline-injected control mice. The early deaths occurred in animals singly housed without bedding and only when food was withheld. Because deaths could be prevented by providing the infected animals with food, it was concluded that metabolic alteractions resulting from the virus infection were responsible for the deaths. As evidence, corticosteroid-inducible hepatic enzymes did not respond to hydrocortisone administration in virus-infected mice housed at 5 degrees C. Phosphoenolpyruvate carboxykinase (PEPCK) (EC 4.1.1.32) was induced significantly in control mice held at 5 degrees C for 5 h, but failed to induce in infected mice in the cold. Tryptophan oxygenase (TO) (EC 1.13.11.11) activity was also induced in control mice at 5 degrees C, but was too low to be measured in livers of all infected mice including those exposed to cold. The conclusion that Sindbis virus-infected mice were unable to make the metabolic adjustments required for survival at 5 degrees C was further indicated by severe hypoglycemia and rapid drop in rectal temperature that occurred in infected mice after 5 h in the cold.

Animals↗
PubMed1979

The use of Reuber hepatoma cells for the study of a lipopolysaccharide-induced macrophage factor: glucocorticoid-antagonizing factor.

Endotoxin-stimulated glucocorticoid-antagonizing factor (GAF) was assayed by its specific inhibition of hydrocortisone-induced synthesis of phosphoenolpyruvate carboxykinase. Defined induction of phosphoenolpyruvate carboxykinase synthesis in hydrocortisone-treated rat hepatoma cells permitted reliable quantitation of GAF and analysis of the mechanism of cortisol antagonism. GAF was present maximally in serum 2 hours after endotoxin challenge in mice; however, GAF production could be suppressed by pretreating mice with indomethacin or cortisol. Endotoxin-tolerant mice were also nonresponsive to endotoxin-stimulated GAF production. Gel filtration on Sephadex G-200 resolved four regions of glucocorticoid-antagonizing activity in serum from endotoxin-poisoned mice, two of which were not present in normal serum. Cortisol antagonism by GAF resembled that of insulin; however, insulin differed from GAF in its ability to antagonize dibutyryl cyclic AMP. Unlike insulin, endotoxin-induced serum glucocorticoid-antagonizing activity was heat-labile at 70 degrees C. GAF antagonism of hydrocortisone was partially reversible but did not act in a competitive manner. Production of hepatoma growth inhibitory activity and glucocorticoid-antagonizing activity in serum were closely associated, indicating a common methanism for their generation.

Animals↗
PubMed1978

Motility of the pathogen and intestinal immunity of the host in experimental cholera.

1) Motility seems to be required for an intimate association with the intestinal mucosa which is necessary for efficient toxin delivery in the pathogenicity of V. cholerae. 2) A vaccine of semipurified flagella (CF) afforded a high degree of active and passive immunity in the rabbit ileum to both homologous and heterologous challenge strains. 3) The nature of the immunoglobulin type involved in the active immunity elicited by CF was not clear but preliminary indications implicate both s-IgA and IgG.

Animals↗
PubMed1978

Elicitation of endotoxemic effects in C3H/HeJ mice with glucocorticoid antagonizing factor and partial characterization of the factor.

C3H/HeJ mice were used to study the origin and nature of endotoxin-induced glucocorticoid antagonizing factor (GAF). In conventional mice GAF is believed to be responsible for a variety of effects that occur as a result of an injection of endotoxin, including the inhibition of hormonal induction of hepatic phosphoenolpyruvate carboxykinase and of glyconeogenesis. Responses in such animals are seen whether the endotoxin is extracted with phenol-water or with trichloroacetic acid. C3H/HeJ mice do not respond (or produce GAF?) after an intravenous injection of phenol-water lipopolysaccharide, but they react normally (produce GAF?) when given a trichloroacetic acid preparation. They also behave the same as conventional animals when injected with serum from poisoned normal mice, especially when the reticuloendothelial system of the donors has been activated by prior injections of Zymosan or heat-killed tubercle bacilli. The C3H/HeJ mice have been used, therefore, as assay animals to establish that peak levels of GAF appear in donor serum about 2 h after an injection of lipopolysaccharide, and it is produced intraperitoneally in C3H/HeJ mice given a mixture of endotoxin and peritoneal exudate cells derived from responder mice. GAF elutes from Sephadex G-200 along with markers of known molecular weight in the region of 100,000 to 200,000. It is inactivated by trypsin and by heating at 75 degrees C for 1 h.

Animals↗
PubMed1978

Role of motility in experimental cholera in adult rabbits.

The role of motility in the pathogenesis of cholera was evaluated in ligated ileal loops of adult rabbits. Four strains of Vibrio cholerae (including both Inaba and Ogawa serotypes of both classical and El Tor biotypes) were compared with their aflagellated, but fully toxigenic and prototrophic, isogenic derivatives as to their ability to produce fluid accumulation in the rabbit gut. The nonmotile mutants required an at least 100-fold-higher dose than their respective wild-type strains to produce comparable fluid accumulation responses. The decreased ability of nonmotile strains to produce a fluid response was not due to their failure to multiply in vivo, since they increased in numbers in the rabbit ileum at the same rate as the wild-type strains, but probably was related to their inability to associate with the intestinal mucosa. After 3 h of incubation, 45 to 53% of motile, [35S]-labeled cells adsorbed to the intestinal wall, whereas only 3 to 15% (depending upon the strain) of the nonmotile bacteria were associated.

Animals↗
PubMed1978

Subcellular fractions for immunizing against pertussis.

Differential centrifugation was used to prepare fractions from broken cells of Bordetella pertussis strain 114. Whole cells and several fractions were then assayed for potency and for safety. Crude ribosomal fractions were uniformly protective. However, ribosomes purified by washing in high salt solution and recentrifugation were at least 40 fold less potent. Protective antigen was found in the wash fluid. Wash fluid was subjected to SDS-polyacrylamide gel electrophoresis. No specific protein or carbohydrate has yet been identified as a protective immunogen. It is clear that ribosomes are not protective, but copurify with protective antigen. SDS-polyacrylamide gel analysis of soluble material purified from ribosomes may be of value in experimental studies on pertussis vaccine. If the protective immunogen can be identified, this procedure may also be of value in vaccine standardization.

Animals↗
PubMed1977

Survey of Toxoplasma antibodies among sheep in western United States.

A survey was conducted to determine the prevalence of toxoplasma antibodies among breeding ewes and among lambs slaughtered for food in western United States. Each serum was tested by the indirect hemaglutination method, using microtiter technique. Agglutination (greater than or equal to 2 +) at the 1:64 dilution was considered to be a positive reaction. Of 2,164 ewes from 18 flocks tested in California, 523 (24%) were seropositive for Toxoplasma gondii, with prevalence rates among flocks ranging from 4 to 51%. In 9 of those flocks, 1,495 ewes were stratified by whether ewes had lambed or were barren. On an overall basis, the antibody prevalence was similar (about 25%) in both groups, but there was a significant difference (P less than 0.05) in 1 flock in which 30% of the nursing ewes were seropositive, compared with 21% of the barren ewes. Of 1,056 market lambs from 19 lots tested, 85 (8%) were seropositive. The antibody prevalence in lambs tested at slaughter in California, by state of origin, were: Oregon, 11/51 (22%); Nevada, 32/159 (20%); Idaho, 12/147 (5%), and California, 30/699 (4%).

Abortion, Veterinary↗
PubMed1977

Nutritional effects of salmonellosis in mice.

Mice infected with a standard challenge of Salmonella typhimurium manifest a number of changes associated with endotoxemia. These changes result in profound alterations in the nutritional and metabolic status of the host. Food and water intake approaches levels of total inanition, blood glucose declines more rapidly than in fasted controls, hepatic phosphoenolpyruvate carboxykinase (the enzyme that is rate limiting in gluconeogenesis) shows diminished activity and loss of cortisol inducibility, and hypothermia, rather than hyperthermia, becomes acute. These changes occur at a time when bacteremia is first demonstrable. This occurs on the 3rd day after infection under the conditions employed. Death occurs in most mice within the next 24 to 48 hr. Mice vaccinated with a highly immunogenic ribosomal preparation and subsequently infected with the standard number of organisms did not manifest the above changes. Other work from this laboratory has established that effects of the type described are elicited by bacterial endotoxin as a result of mediating substances released into the blood by cells of the reticuloendothelial system. Presumably these substances appear in blood of infected mice as well.

Animals↗
PubMed1977

Evaluation of surface components of Vibrio cholerae as protective immunogens.

Surface components of a motile Inaba strain (CA401) were removed from washed cells by low-speed shearing. Flagella contaminated with a vesicular material (designated as crude flagella [CFA1) were obtained by differential centrifugation of the shear fluid. Vesicles were obtained from a nonflagellated mutant by the same procedure. Homogeneous small vesicles were obtained in diminished yield from CsCl gradients of CF preparations. Treatment of CF with sodium deoxycholate removed the vesicular material and flagellar sheaths and yielded naked flagella (NF). The ability of these preparations of passively protect infant mice suckled by CFW mothers that had been immunized at the time of mating was compared, on a dry-weight basis, with commercial vaccine (CV). Eight-day-old mice were challenged orally with more than 1,000 50% lethal doses of either the homologous or a heterologous (Ogawa Ca411) strain. The most effective immunogen was CF, which provided complete protection at 1 microng against both challenges. CF and vesicles provided 50- to 100-fold greater protection than CV against homologous challenge. With heterologous challenge, vesicles were 10-fold more protective than CV, markedly less protective than CF. The NF offered only slightly greater protection than CV against both challenges. Immunoelectrophoresis revealed an antigen in CF distinct from vesicles, cell wall lipopolysaccharide or NF. This antigen is not present in the nonflagellated mutant and is apparently associated with motility,

Animals↗
PubMed1977

Use of fluorescent antibody in studies of immunity to cholera in infant mice.

Infant mice 8 days of age were infected orally with virulent, motile, classical or El Tor strains of Vibrio cholerae and with nonmotile mutants of low virulence derived from the same strains. At intervals of 8 and 12 h postinfection, frozen thin sections of the ileum were prepared, stained with fluorescein isothiocyanate-labeled rabbit anti-vibrio antibody, and examined with the fluorescence microscope. The motile organisms were present in larger numbers, especially at 12h, and had penetrated the intervillous spaces and crypts of Lieberkuhn more completely than nonmotile vibrios. Dilution counts were made on various regions of the intestines of infant mice challenged orally 12 h previously with either motile or nonmotile strains of V. cholerae. Greater numbers of organisms were found, especially in the upper intestinal regions, when motile organisms were used. Low numbers of vibrios, limited mostly to the lumen, were seen in the ileum of infant mice infected with motile organisms when the infants were the offspring of mothers that had been immunized with crude flagellar vaccine or a vesicular preparation derived from the vibrio cell surface. The distribution of vibrios in this case was similar to that found in infected infants of unvaccinated mothers challenged with nonmotile organisms. Motility appears to enable the bacteria to better populate the upper regions of the intestinal tract and to avoid the washing effects of secretions and peristalsis. Antibacterial immunity may function, at least in part, by making it impossible for motile vibrios to accomplish this widespread distribution within the ileum.

Animals↗