Resistance to tetracycline (Tc), an inhibitor of protein synthesis, decreases its effectiveness for the treatment of bacterial infections. Tc resistance (TcR) can be mediated by the ribosomal protection protein, Tet(O), which was first reported in Campylobacter jejuni, a cause of bacterial diarrhea worldwide. Tet(O) confers TcR by mediating Tc release from 70S ribosomes, thus restoring protein synthesis. Tet(O) is widely distributed in a variety of bacterial genera, restraining the clinical use of Tc. This thesis is the first investigation into the role of the conserved set of amino acid residues, YSPVST, occupying positions 507-512 at the tip of domain IV of Tet(O). Impaired Tc release from 70S ribosomes observed with Tet(O)mutants lacking one or more of these conserved residues suggests residues at positions 509-512 play a role in Tet(O)-mediated TcR. This study provides insight into the molecular mechanism of TcR, which is essential for the development of novel therapeutics.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1973. / Typescript (photocopy). Includes bibliographical references (leaves 75-83). Also issued in print.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1970. / Typescript (photocopy). Includes bibliographical references (leaves 45-49). Also issued in print.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1970. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 45-49).

Thesis (M.S.)--University of Michigan, Ann Arbor, 1973. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 75-83).

Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--University of Wisconsin, 1964. / Abstracted in Dissertation abstracts, v. 25 (1964) no. 6, p. 3262. Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.Sc.D.)--Boston University. School of Graduate Dentistry, 1969. (Prosthetics) / Bibliography, colored photographs included.

Orientador: Idelmo Rangel Garcia Júnior / Banca: Osvaldo Magro Filho / Banca: Luis Eduardo Marques Padovan / Resumo: O presente estudo analisou o processo de reparo ósseo em cavidades ósseas experimentais realizadas em tíbias de coelho, quando implantado partículas de enxerto ósseo homógeno, tratadas com solução de tetraciclina. Foram realizadas análises histológicas e submetidas a tratamento estatístico após histometria. Os resultados mostraram que não houve, estatisticamente, diferenças significantes entre o grupo controle onde não houve nenhuma implantação, e o grupo tratado utilizando a tetraciclina. O processo de reparo ocorreu de maneira similar em ambos os grupos. Não houve reabsorção completa dos fragmentos ósseos implantados, permanecendo até o período estudado de 30 dias pós-operatórios. / Abstract: The aim of the present study was to evaluate the bone repair process in experimental bone cavities which were realized in rabbit tibias when particles of homogenous bone graft were implanted and treated with tetracycline. Histolological analysis were carried out and undergone a statistical treatment after HISTOMETRIA. The results showed that the hydrochloric tetracycline didnþt interfered on the bone graft performance, which was used on the treatment of experimental bone defects. There wasnþt histological evidence of the decalcifier action of tetracycline; it could be the medicine exposion time of the bone graft. Evaluating the statistical results; it was observed that the tetracycline didnþt interfered on bone repair process, moreover its presence doesnþt cause delay or any significant interference that changes the healing process. / Mestre

Aim: Microbial biofilm matrix contains polysaccharides and proteins and can require extracellular nucleic acids for initial formation. Experiments were designed to identify infectious pathogens in human aneurysms and to characterize biofilm formed by calcified human arterial-derived nanoparticles. Materials & method: A total of 26 different microbial pathogens were isolated from 48 inflammatory aneurysms. Consistent amounts (0.49 McFarland units) of nanoparticles derived from similar tissue were seeded into 24-well plates and cultured for 21 days in the absence (control) or presence of RNase, tetracycline or gentamicin. Results: Control biofilm developed within 14 days, as detected by concanavalin A and BacLight™ Green staining. The formation of biofilm in wells treated with RNase was not different from the control; however, gentamicin partially inhibited and tetracycline completely inhibited biofilm formation. Therefore, nanoparticle biofilm retains some characteristics of conventional bacterial biofilm and requires protein-calcium interactions, although extracellular RNA is not required. Conclusion: This model system may also allow study of nanosized vesicles derived from donor tissue, including any microbes present, and could provide a useful tool for in vitro investigation of nanoparticle biofilm formation.