Thesis (M.S.)--Catholic University of America. / Includes bibliographical references.

No description available.

No description available.

Thesis (Ph. D.)--University of Florida, 1997. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis - Univ. of Michigan.

Thesis (Ph. D.)--University of Florida, 1997. / Includes bibliographical references.

Thesis (Ph. D.)--New York University, 1929. / Bibliography: p. 787, 235.

Treponema hyodysenteriae is the causative agent of swine dysentery, a mucohemorrhagic disease of the intestines. T. hyodysenteriae requires phospholipids and cholesterol (or cholestanol) for growth, and it produces a a-hemolysin (TH) which is induced (300 fold) by the addition of RNA core to cultures. TH is bound to the RNA core which acts as a carrier or stabilizer. I\lyobjectives were to (i) obtain successful continuous growth of T. hyodysenteriae; (ii) study the production of the hemolysin produced by T. hyodysenteriae; (Ui) study the effects of different oligonucleotide carriers on the induction of hemolysin, (iv) examine various purification procedures for nipid, efficient partial purification of the hemolysin, (v) separate the hemolysin from the RNA core carrier, and (vi) to detennme whether T. hyodysenteriae can use coprostanol, the most common intestinal sterol, to satisfy its sterol requirement. I found that optimal growth of T. hyodysenteriae could be achieved by using BHI- glucose broth supplemented with calf serum (I O~/o). serum replacement (100/0), or phosphatidylcholine liposomes which contained cholesterol or cholestanol. Optimal growth required 1 % 02 and stirring of the culture. l\laximal hemolytic titers were obtained during late-log to early-stationary phase by cultures grown in the presence of RNA core. Hemolysin production was induced as soon as 5 minutes after addition of RNA core to cultures. This production was inhibited by chloramphenicol. Polyguanylic acid and RNase treated RNA core did not significantly increase hemolytic titers of cultures grown in their presence. Partial purification of hemolysin was achieved by acetic acid clarification followed by ammonium sulfate precipitation (65% saturation). With these procedures > 90% of the hemolytic activity was recovered. Although, hydroxylapatite adsorption and polyethyleneimine precipitation completely adsorbed or precipitated hemolytic activity I I was unable to efficiently recover the activity. Partially purified hemolysin was c}10toxic to CHO cells, and caused lysis rather than the rounding effect caused by many cytotoxins. / Master of Science

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1977. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / Ph.D.

The conditions by which the production, in liquid media, of hemolytic activity by growing cells of T. hyodysenteriae and T. innocens are described. / From a ribonucleic acid added culture broth of T. hyodysenteriae, two hemolysins are shown in the supernatant. For each of them, a purification scheme allowing the obtention of an homogeneous hemolytic preparation by gel filtration and electrophoresis, is proposed. One hemolysin is associated with ribonucleic acid (HN) while the later is associated with bovine serum albumin (HP). They share some properties: their synthesis is blocked by chloramphenicol, they do not have proteolytic or phospholipasic activities, they are insensitive to oxygen and their activity does not require bivalent cations or is sensitive to EDTA's action; they are lytic to all red blood cell's type tested. They differ by the size of their apparent molecular weight, their mode of action, the stability of their activity to temperature and different pH and, their pattern of sensitivity to proteolytic enzymes. / The isolation of a non-hemolytic mutant strain of T. hyodysenteriae and its use in a ligated ileal loop model in rabbit has shown that there is a relation between the loss of the hemolytic activity and the loss of the enterotoxic activity.