Thesis (M.A.)--Boston University / Transfer of fertilized ova from a donor female to a uterine foster mother can be a valuable tool for attack of problems of gen etics, cancer, embryologJ, growth, immunology, and fertilization. The technique has been practiced in the rabbit, mouse, rat, and sheep with varying degrees of success. Holding media for the ova usually consist of blood serum, alone, or modified with a balanced saline solution. Diffusion chambers constructed of Millinore Filter membrane have proved valuable for 'in vivo' and 'in vitro' tissue culture and transnlantation. These chambers serve the useful function of mechanically isolating the contents from surrounding tissues and free cells, while providing diffusion of metabolites and oxygen into the chamber to nourish the enclosed tissue . Experimental procedure Donor albino females were mated with albino males. Approximately 24-33 hours after fertilization, when the ova were in the two cell stage, salpingectomies were performed. The ova were removed from the uterine tubes, and transferred to the ovarian bursa of pseudopregnant albino recipients [TRUNCATED]

Thesis (Ph.D.)--Boston University. / Mineral metabolism and certain circulatory phenomena, all of which are thought to be influenced by the steroid hormones of the adrenal cortex, were studied in hibernating, cold stressed, and normal hamsters. Hibernation was induced by prolonged exposure to a temperature of 6°C. Chronic cold stress resulted from exposure of hamsters to the same conditions which induced hibernation, but for a shorter time. Acute cold stress was brought about by surrounding the body of the test animals with a copper coil through which ice water was pumped. Body temperature was measured by means of a thermistor type thermometer with the sensing probe inserted deep into the cheek pouch.

by Royal Alfred McGraw. / Vita. / Thesis (M.S.)--Florida State University. / Bibliography: leaves 42-43.

Adenine phosphoribosyl transferase is a ubiquitous enzyme which salvages endogenous adenine, via the nucleotide AMP, for use by the cell. This activity, in conjunction with other interconnected purine salvage mechanisms is an energy-efficient way for the cell to satisfy its purine requirements. APRT is a target molecule in certain human diseases, for chemotherapeutics, and in vivo mutagenesis studies. There is little known about structure-function relationships in APRT. In the absence of solved three-dimensional crystal structures, we have explored structure-function relationships in APRT by sequence comparison, in vitro mutagenesis and kinetic analysis, protein crosslinking, and in vivo selection of mutant enzymes with altered substrate affinities. Chinese hamster APRT shares identifiable sequence similarities to all other phosphoribosyl transferases, and many other nucleotide binding proteins, in regions which probably serve closely similar functions across diverse protein families. Predicted secondary structures of CHO APRT are very similar to other APRT molecules, and to a lesser degree to other phosphoribosyl transferases. Residues of part of the generalized nucleotide binding motif of APRT were found to have specific roles in binding substrate, which can be extrapolated to the same functional elements in other nucleotide binding proteins. In addition, mutants identified by selection for altered substrate affinities are widely dispersed in the primary sequence. Although APRT is thought to exist as a dimer in its native context, certain mutants of APRT which have impaired ability to form dimers appear to have near-wildtype activity. / Graduate

No description available.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 176-192). / Also available by subscription via World Wide Web / xi, 192 leaves, bound ill. (some col.) 29 cm

Thesis (Ph.D.)--Boston University / Functional competence of intact pancreas and neonatal pancreatic implants was determined in normal and alloxan diabetic Golden Hamsters by measurement of the ability to release insulin-like activity (ILA) in vitro and in vivo as bioassayed by the rat epididymal fat ped technique. Islets were determined to be functionally competent before birth. ILA was released in vitro prior to the second post-natal day when beta cells first showed definite granulation. By 30 days, beta cells showed mature granulation but with advancing age, they released less ILA. It is suggested that the corresponding development of exocrine pancreas results in proteolytic inactivation of ILA in vitro [TRUNCATED]

Graduation date: 1997

Thesis (M.A.) - Simon Fraser University, 2006. / Theses (Dept. of Psychology) / Simon Fraser University. Also issued in digital format and available on the World Wide Web.

Thesis (M. Phil.)--University of Hong Kong, 1984.