Portal fibroblasts are newly discovered liver cells that may be of particular importance in biliary fibrosis. Recent data indicate that portal fibroblasts express NTPDase2, an ecto-nucleoside triphosphate diphosphohydrolase. Portal fibroblasts exist within the peri-portal regions of rat livers and express NTPDase2 adjacent to the basolateral side of intrahepatic bile ducts. Because extracellular nucleotides regulate secretion via activation of P2Y purinergic receptors, extracellular nucleotide hydrolysis via NTPDase2 makes NTPDase2 a potential regulator of bile ductular secretion. We propose that NTPDase2 expression may be altered in biliary fibrosis, especially in conditions in which bile duct epithelia are the target of disease. To test this hypothesis we have contrasted the distribution of NTPDase2 in normal and diseased liver states. Using confocal immunofluorescence, we assessed differences in expression of NTPDase2 in liver biopsy specimens from normal liver, primary biliary cirrhosis (PBC), and hepatitis C (HepC). We found that NTPDase2 was down regulated in the peri-portal regions of patients with PBC when compared to normal patients. Hepatitis C, however, showed NTPDase2 staining equal to or nearly equal to that of normal liver. The intermediate filament vimentin was down regulated in both PBC and Hep C when compared to normal liver. We conclude that NTPDase2 expression is down regulated in PBC but not Hep C, while vimentin is down regulated in both disease states when compared to normal liver.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 118-130.

Atlantic salmon (Salmo salar) parr-smolts were exposed to sublethal concentrations of cypermethrin, chlorothalonil, quintozene or atrazine to determine if they affected osmoregulation. After 96 h of exposure to a pesticide, Na+K+-ATPase, hematocrit, liver somatic index (LSI), plasma sodium, chloride, and cortisol concentrations were determined. There were no mortalities observed following a 24-h seawater challenge. No effects were seen with cypermethrin exposure. Chlorothalonil exposure resulted in increases in plasma Na+ concentrations following the seawater challenge in the 0.18 and 3.6 μg/L groups. For quintozene, decreases in LSI was seen at each concentration, and decreases in Na+K+-ATPase activity was seen at 0.55 μg/L as well as a decrease in Na+ concentrations at the highest exposure concentration. Atrazine exposure increased Na+K+-ATPase activity in the 1 and 100 μg/L groups, and plasma cortisol concentrations at100 μg/L. Overall, the pesticides examined had minimal effects on fish osmoregulation and stress at the concentrations tested.

Single particle electron cryomicroscopy (cryo-EM) is a rapidly developing structural biology technique for the study of macromolecular protein complexes. Presently, cryo-EM fills an important niche by facilitating acquisition of 3-D structures of protein complexes not amenable to structure determination by other techniques. Expansion of cryo-EM beyond this niche requires continued improvement in the types of specimens that can be studied as well as the final resolutions achieved. Two studies were undertaken to address these issues. The first examined resolution limitations by quantifying the effect of beam-induced motion in images of beam-sensitive paraffin crystals. The second explored the possibility of using cryo-EM to study the interaction of small effector proteins with a large multi-protein complex, V-ATPase. The results of these studies exposed the fact that fundamental aspects of the imaging and specimen preparation processes remain poorly understood and must be addressed to facilitate future improvements in cryo-EM structure determination.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 6 uppsatser.

Thesis (M. App. Sc.)--Victoria University (Melbourne, Vic.), 2006. / Includes bibliographical references.

Thesis (Ph.D.)--University of Wollongong, 2003. / Typescript. Includes bibliographical references: leaf 168-188.

Thesis (Ph. D.)--University of Virginia, 1998. / Spine title: Cryo-EM of Ca²⁺-ATPase from SR. Includes bibliographical references (p. 149-159). Also available online through Digital Dissertations.

Thesis (Ph.D.)--Ohio University, June, 2008. / Title from PDF t.p. Includes bibliographical references.