EXPERIMENTAL ENTERIC SHIGELLA AND VIBRIO INFECTIONS IN MICE AND GUINEA PIGS

A method has been devised for inhibiting the normal enteric flora, permitting long term asymptomatic enteric infections of mice and guinea pigs with streptomycin-resistant strains of Shigella flexneri or Vibrio cholerae. Introduction of a streptomycin-resistant strain of E. coli into the intestinal tract of experimental animals resulted in a rapid elimination of the enteric pathogens studied. No in vitro production of antibiotic substances by this coli strain could be demonstrated. Active and oral passive immunization did not noticeably influence the number of Shigella or Vibrio organisms recoverable from the feces of infected animals.

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Effects of Macronutrients on the In Vitro Production of ClpB, a Bacterial Mimetic Protein of α-MSH and Its Possible Role in Satiety Signaling

Nutrients ◽

10.3390/nu11092115 ◽

2019 ◽

Vol 11 (9) ◽

pp. 2115 ◽

Cited By ~ 7

Author(s):

Manon Dominique ◽

Jonathan Breton ◽

Charlène Guérin ◽

Christine Bole-Feysot ◽

Grégory Lambert ◽

...

Keyword(s):

Peptide Yy ◽

In Vitro Production ◽

E Coli ◽

Melanocyte Stimulating Hormone ◽

Satiety Hormone ◽

Underlying Mechanisms ◽

Anorexigenic Effect ◽

Vitro Production ◽

Protein Bovine Serum Albumin

Gut microbiota can influence the feeding behavior of the host, but the underlying mechanisms are unknown. Recently, caseinolytic protease B (ClpB), a disaggregation chaperon protein of Escherichia coli, was identified as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), an anorexigenic neuropeptide. Importantly, ClpB was necessary for E. coli to have an anorexigenic effect in mice, suggesting that it may participate in satiety signaling. To explore this further, we determined the short-term (2 h) effects of three macronutrients: protein (bovine serum albumin), carbohydrate (D-fructose) and fat (oleic acid), on the production of ClpB by E. coli and analyzed whether ClpB can stimulate the secretion of the intestinal satiety hormone, peptide YY (PYY). Isocaloric amounts of all three macronutrients added to a continuous culture of E. coli increased ClpB immunoreactivity. However, to increase the levels of ClpB mRNA and ClpB protein in bacteria and supernatants, supplementation with protein was required. A nanomolar concentration of recombinant E. coli ClpB dose-dependently stimulated PYY secretion from the primary cell cultures of rat intestinal mucosa. Total proteins extracted from E. coli but not from ClpB-deficient E. coli strains also tended to increase PYY secretion. These data support a possible link between E. coli ClpB and protein-induced satiety signaling in the gut.

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The in-vitro production of α toxin, θ hæmolysin and hyaluronidase by strains ofCl. welchii type A, and the relationship of in-vitro properties to virulence for guinea-pigs

The Journal of Pathology and Bacteriology ◽

10.1002/path.1700570111 ◽

1945 ◽

Vol 57 (1) ◽

pp. 75-85 ◽

Cited By ~ 24

Author(s):

D. G. Evans

Keyword(s):

Guinea Pigs ◽

Type A ◽

In Vitro Production ◽

Relationship Of ◽

Vitro Production ◽

The Relationship

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Hematopoietic stem cell development requires transient Wnt/β-catenin activity

Journal of Experimental Medicine ◽

10.1084/jem.20120225 ◽

2012 ◽

Vol 209 (8) ◽

pp. 1457-1468 ◽

Cited By ~ 85

Author(s):

Cristina Ruiz-Herguido ◽

Jordi Guiu ◽

Teresa D'Altri ◽

Julia Inglés-Esteve ◽

Elaine Dzierzak ◽

...

Keyword(s):

Hematopoietic Cells ◽

In Vitro Production ◽

Mouse Development ◽

Hematopoietic Stem ◽

Embryonic Life ◽

Vitro Production ◽

Mutant Cells ◽

Endothelial Precursors

Understanding how hematopoietic stem cells (HSCs) are generated and the signals that control this process is a crucial issue for regenerative medicine applications that require in vitro production of HSC. HSCs emerge during embryonic life from an endothelial-like cell population that resides in the aorta-gonad-mesonephros (AGM) region. We show here that β-catenin is nuclear and active in few endothelial nonhematopoietic cells closely associated with the emerging hematopoietic clusters of the embryonic aorta during mouse development. Importantly, Wnt/β-catenin activity is transiently required in the AGM to generate long-term HSCs and to produce hematopoietic cells in vitro from AGM endothelial precursors. Genetic deletion of β-catenin from the embryonic endothelium stage (using VE-cadherin–Cre recombinase), but not from embryonic hematopoietic cells (using Vav1-Cre), precludes progression of mutant cells toward the hematopoietic lineage; however, these mutant cells still contribute to the adult endothelium. Together, those findings indicate that Wnt/β-catenin activity is needed for the emergence but not the maintenance of HSCs in mouse embryos.

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In vivo pharmacokinetics and in vitro production of cocaethylene in pregnant guinea pigs

Life Sciences ◽

10.1016/0024-3205(96)00149-x ◽

1996 ◽

Vol 58 (20) ◽

pp. 1695-1704 ◽

Cited By ~ 3

Author(s):

Jennifer E. Kron ◽

Richard J. Konkol ◽

George D. Olsen

Keyword(s):

Guinea Pigs ◽

In Vitro Production ◽

Vitro Production ◽

In Vivo Pharmacokinetics

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Lipoprotein Release by Bacteria: Potential Factor in Bacterial Pathogenesis

Infection and Immunity ◽

10.1128/iai.66.11.5196-5201.1998 ◽

1998 ◽

Vol 66 (11) ◽

pp. 5196-5201 ◽

Cited By ~ 61

Author(s):

Hongwei Zhang ◽

David W. Niesel ◽

Johnny W. Peterson ◽

Gary R. Klimpel

Keyword(s):

Bacterial Infections ◽

Cytokine Production ◽

In Vitro Production ◽

Dot Blot ◽

E Coli ◽

Dot Blot Assay ◽

Dot Blot Analysis ◽

Vitro Production ◽

Culture Supernatants

ABSTRACT Lipoprotein (LP) is a major component of the outer membrane of bacteria in the family Enterobacteriaceae. LP induces proinflammatory cytokine production in macrophages and lethal shock in LPS-responsive and -nonresponsive mice. In this study, the release of LP from growing bacteria was investigated by immuno-dot blot analysis. An immuno-dot blot assay that could detect LP at levels as low as 100 ng/ml was developed. By using this assay, significant levels of LP were detected in culture supernatants of growing Escherichia coli cells. During mid-logarithmic growth, approximately 1 to 1.5 μg of LP per ml was detected in culture supernatants from E. coli. In contrast, these culture supernatants contained 5 to 6 μg/ml of lipopolysaccharide (LPS). LP release was not unique toE. coli. Salmonella typhimurium, Yersinia enterocolitica, and two pathogenic E. coli strains also released LP during in vitro growth. Treatment of bacteria with the antibiotic ceftazidime significantly enhanced LP release. Culture supernatants from 5-h cultures of E. coli were shown to induce in vitro production of interleukin-6 (IL-6) by macrophages obtained from LPS-nonresponsive C3H/HeJ mice. In contrast, culture supernatants from an E. coli LP-deletion mutant were significantly less efficient at inducing IL-6 production in C3H/HeJ macrophages. These results suggest, for the first time, that LP is released from growing bacteria and that this released LP may play an important role in the induction of cytokine production and pathologic changes associated with gram-negative bacterial infections.

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Differential induction of pro- and anti-inflammatory cytokines in whole blood by bacteria: effects of antibiotic treatment.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.7.1439 ◽

1997 ◽

Vol 41 (7) ◽

pp. 1439-1443 ◽

Cited By ~ 35

Author(s):

J T Frieling ◽

J A Mulder ◽

T Hendriks ◽

J H Curfs ◽

C J van der Linden ◽

...

Keyword(s):

Whole Blood ◽

Cytokine Production ◽

Polymyxin B ◽

Bacterial Strains ◽

In Vitro Production ◽

E Coli ◽

Gram Positive Bacteria ◽

Anti Inflammatory ◽

Vitro Production

The in vitro production of interleukin-1beta (IL-1beta), IL-6, and the IL-1 receptor antagonist (IL-1ra) in whole blood upon stimulation with different bacterial strains was measured to study the possible relationship between disease severity and the cytokine-inducing capacities of these strains. Escherichia coli, Neisseria meningitidis, Neisseria gonorrhoeae, Bacteroides fragilis, Capnocytophaga canimorsus, Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae, and Streptococcus pyogenes induced the cytokines IL-1beta, IL-6, and IL-1ra. Gram-negative bacteria induced significantly higher levels of proinflammatory cytokine production than gram-positive bacteria. These differences were less pronounced for the anti-inflammatory cytokine IL-1ra. In addition, blood was stimulated with E. coli killed by different antibiotics to study the effect of the antibiotics on the cytokine-inducing capacity of the bacterial culture. E. coli treated with cefuroxime and gentamicin induced higher levels of IL-1beta and IL-6 production but levels of IL-1ra production similar to that of heat-killed E. coli. In contrast, ciprofloxacin- and imipenem-cilastatin-mediated killing showed a decreased or similar level of induction of cytokine production as compared to that by heat-killed E. coli; polymyxin B decreased the level of production of the cytokines.

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Comparison between in vivo-derived and in vitro-produced pre-elongation embryos from domestic ruminants

Reproduction Fertility and Development ◽

10.1071/r96079 ◽

1997 ◽

Vol 9 (3) ◽

pp. 341 ◽

Cited By ~ 114

Author(s):

Jeremy G. Thompson

Keyword(s):

Adult Life ◽

In Vitro Production ◽

Domestic Ruminants ◽

Developmental Physiology ◽

In Vitro Embryo Production ◽

Vitro Production ◽

Subcellular Level

In vitro production of ruminant embryos has become routine and is increasingly available as a commercial service to dairy, meat and wool producers. However, the efficiency of producing viable embryos and the development of such embryos after transfer to recipients are perceived to be inferior to that which occurs in vivo. The present review outlines the biochemical and morphological similarities and differences between embryos produced In vitro and those produced in vivo. Some measures of metabolism are not markedly different between In vitro- and in vivo-derived blastocysts. However, at a cellular and subcellular level, differences in metabolism, morphology and ultrastructure have been described, as has susceptibility to manipulation and cryopreservation. Most importantly are the differences in lambing and calving rates and the reports of abnormal fetal development from embryos produced In vitro. These latter observations are of major concern, as they suggest that the In vitro environment may affect subsequent developmental physiology. At the extreme, these effects may not be expressed until adult life. Further efforts to improve the efficiency of In vitro embryo production must be accompanied by a commitment to assess the long-term consequences of these procedures. Extra keyword: development.

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