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

1945 ◽  
Vol 57 (1) ◽  
pp. 75-85 ◽  
Author(s):  
D. G. Evans
Keyword(s):  
Guinea Pigs ◽  
Type A ◽  
In Vitro Production ◽  
Relationship Of ◽  
Vitro Production ◽  
The Relationship

scholarly journals The release of an endogenous pyrogen from guinea pig leukocytes in vitro: a new model for investigating the role of lymphocytes in fevers induced by antigen in hosts with delayed hypersensitivity.

1977 ◽  
Vol 145 (5) ◽  
pp. 1288-1298 ◽  
Author(s):  
P Chao ◽  
L Francis ◽  
E Atkins
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Polymorphonuclear Leukocytes ◽  
Delayed Hypersensitivity ◽  
Endogenous Pyrogen ◽  
Phagocytic Cells ◽  
Relationship Of ◽  
The Relationship

Guinea pig periotoneal exudate (PE) cells incubated overnight in vitro with heat-killed Staphylococci released an endogenous pyrogen (EP) that could be assayed by intravenous injection in rabbits. The febrile responses were linearly related to the dosage of EP over an eightfold range. PE cells derived from guinea pigs with delayed hypersensitivity (DH) to bovine gamma globulin (BGG), also released EP when incubated with antigen in vitro. This reaction was specific and did not occur withe PE cells from normal or complete Freund's adjuvant-sensitized guinea pigs. Studies indicated that monos and/or polymorphonuclear leukocytes rather than lymphocytes were the source of EP. However, when incubated with BGG and sufficient dosages of BGG-sensitized lymphocytes, normal PE cells released EP over a 42 h period. These results suggest that antigen stimulates specifically sensitized lymphocytes to release an agent (perhaps a lymphokine) that activates phagocytic cells to release EP. This model offers unique advantages for investigating in vitro the role of the lymphocyte in antigen-induced fever in DH as well as the relationship of this lymphocyte-induced activity to other known biologic activities mediated by antigen stimulated lymphocytes.

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

Life Sciences ◽  
1996 ◽  
Vol 58 (20) ◽  
pp. 1695-1704 ◽  
Author(s):  
Jennifer E. Kron ◽  
Richard J. Konkol ◽  
George D. Olsen
Keyword(s):  
Guinea Pigs ◽  
In Vitro Production ◽  
Vitro Production ◽  
In Vivo Pharmacokinetics

scholarly journals EXPERIMENTAL ENTERIC SHIGELLA AND VIBRIO INFECTIONS IN MICE AND GUINEA PIGS

1956 ◽  
Vol 104 (3) ◽  
pp. 411-418 ◽  
Author(s):  
Rolf Freter ◽  
Keyword(s):  
Guinea Pigs ◽  
Shigella Flexneri ◽  
Passive Immunization ◽  
Coli Strain ◽  
In Vitro Production ◽  
E Coli ◽  
Enteric Infections ◽  
Vitro Production

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.

THE IN VITRO PRODUCTION OF ANDROGENS BY FOLLICULAR TISSUE OF RABBITS

1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz
Keyword(s):  
In Vitro Production ◽  
Vitro Production

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

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