Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Abstracted in Dissertation abstracts, v. 16 (1956) no. 2, p. 222. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 221-235).

Polyacrylamide gel electrophoresis was employed in an investigation of peroxidase isozymes extracted from the mature fruits of seventeen individuals belonging to the genusThe purpose of this study was to develop procedures which could supplement existing information contributing to the biosystematics of this genus.Samples were detected on 5%-20% linear gradient gels in a sodium borate - boric acid buffer (pH, 9.0). Following electrophoresis, incubation was carried out in a solution containing benzidine dihydrochioride and hydrogen peroxide in an acetate buffer (pH, 4.5).Resulting zymograms were analyzed and eight different isozyme bands identified, based on width, staining characteristics and relationship to a horseradish peroxidase standard zymogram. Composite zymograms were drawn for each Species, based on frequency of occurrence of individual bands. Within each species, some isozymes were observed in 100% of the individuals, while other bands appeared in 20% to 92% of the gels examined. Three of the seven species investigated exhibited unique zymograms. Similarities were noted in isozyme patterns among species. Three groups of species were established based on the presence or absence of certain variable bands. Two of these groups had some correspondence to series groupings based on observable morphological characteristics. A third group consisted of species not related in traditional classification.

Thesis (M. Med. Sc.)--University of Hong Kong, 2004. / Also available in print.

Leaf surface area present on black cottonwood (Populus trichocarpa) and Douglas hawthorn (Crataegus douglasi) was measured indirectly using a point frame, photographs, and a canopy analyzer. Each was compared to directly measured leaf surface area. Six black cottonwood and 3 Douglas hawthorn shrubs were selected in 1996 and 9 black cottonwood and 3 Douglas hawthorn shrubs in 1997. Shrubs were selected based on size and isolation. Each indirect method was applied prior to removing a portion of leaves from each shrub. Shrubs were defoliated in 3 to 7 increments and leaf surface area of each was measured. After shrubs were completely defoliated increments of measured leaf areas were added to subsequently removed leaf areas to determine the measured leaf area present on a shrub each time indirect methods were applied. Measured leaf areas were paired with indirect method values and regression equations were developed. Correlation coefficients for regressions were 0.76 for black cottonwood and 0.70 for Douglas hawthorn for the point frame, 0.91 for black cottonwood and 0.79 for Douglas hawthorn for the photographs, 0.62 for black cottonwood and 0.61 for Douglas hawthorn when shrub volume was included for the canopy analyzer. Photographs took 20 minutes to set up and take pictures followed by 1.5 hours for processing images in Idrisi and Picture Publisher. The point frame required 45 minutes to 1.5 hours field time and 5 to 10 minutes to process data. The canopy analyzer was the most rapid of the techniques requiring less than 5 minutes to secure a field measurement and enter this value into the regression equation. Canopy analyzer reliability was the lowest of the methods studied. / Graduation date: 1999

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 132-147). Also available on the World Wide Web.

Herbs have been used for many centuries in diverse civilizations for the treatment of heart disease. Only a few natural supplements claim to have direct cardiovascular actions including hawthorn (Crataegus spp.) and berberine derived from the Berberidaceae family. Several different studies indicate important cardiovascular effects of hawthorn and berberine. For example, both exert positive inotropic effects and have been used in the treatment of congestive heart failure. Recently, it was shown that hawthorn extract preparations cause negative chronotropic effects in a cultured neonatal murine cardiomyocyte assay independent of beta-adrenergic receptor blockade. The aim of this study was to further characterize the effect of hawthorn extract to decrease the contraction rate of cultured cardiomyocytes. We hypothesized that hawthorn extract may be acting through muscarinic receptors to decrease contraction rate of cardiomyocytes. Atrial and ventricular cardiomyocytes were treated with hawthorn extract in the presence of atropine or himbacine. Changes in the contraction rate of cultured cardiomyocytes revealed that both muscarinic antagonists significantly attenuated the negative chronotropic activity of hawthorn extract. Using quinuclidinyl benzilate, L-[benzylic-4,4'-3H] ([³H]-QNB) as a radioligand antagonist, the effect of a partially purified hawthorn extract fraction to inhibit muscarinic receptor binding was quantified. Hawthorn extract fraction 3 dose-dependently inhibited [³H]-QNB binding to mouse heart membranes. These findings suggest that muscarinic receptors may be involved in the negative chronotropic effect of hawthorn extracts in neonatal murine cardiomyocytes. Berberine exhibits variable positive and negative chronotropic effects in different species. Our first aim was to examine the effect of berberine in a cultured neonatal murine cardiomyocyte assay. Our study demonstrates that berberine has significant negative chronotropic actions on cardiomyocytes which is not an effect of beta-adrenergic receptor blockade. Pertussis toxin (PTX), a Gi/o protein inhibitor, blocked the negative chronotropic activity of berberine. Muscarinic, adenosine, opioid, and α₂ receptors are coupled through a G-protein (Gi/o) to adenylyl cyclase in an inhibitory fashion. Activation of these receptors are primarily responsible for PTX-sensitive negative chronotropic effects in heart. We hypothesized that berberine may be acting through one of these receptor type to decrease contraction rate of cardiomyocytes. For this purpose, we studied the effects of the muscarinic-receptor antagonists, atropine, himbacine, or AF- DX 116 on the negative chronotropic activity of berberine. Muscarinic antagonists completely blocked the effect of berberine on contraction rate of cardiomyocytes, whereas the bradycardic effect of berberine was not inhibited by the opioid, adenosine, or α2 receptor antagonists naloxone, CGS 15943, or phentolamine, respectively. Using [³H]QNB as a radioligand, we demonstrated that berberine bound to muscarinic receptors of adult mouse heart membranes with relatively high affinity. Furthermore, berberine dose-dependently inhibited [³H]QNB binding to muscarinic M2 receptors exogenously expressed in HEK 293 cells. Therefore, the findings of the present study suggest that berberine has muscarinic agonist effects in cultured neonatal murine cardiomyocytes, potentially explaining reported physiological effects of berberine. Cardiac hypertrophy represents the most important factor in the development of congestive heart failure. We investigated the inhibitory effect of berberine on hypertrophy of H9c2 cells. In rat heart-derived H9c2 myoblast cells treated with different hypertrophic agonists such as insulin growth factor II (IGF-II), arginine vasopressin (AVP), phenylephrine, and isoproterenol, protein content and size of cells were significantly increased compared to control group. However, the number of H9c2 cells after treatment with hypertrophic agonists did not differ significantly compared to control. The increases in area of cells and protein content induced by the hypertrophic agonists were inhibited by treatment with berberine in a concentration-dependent manner. Our findings have provided the first scientific evidence that berberine may have an inhibitory effect on hypertrophy of heart-derived cells, and provide a rationale for further studies to evaluate berberine's cardiac activity. / Graduation date: 2010

Speciation is the process by which life diversifies into discrete forms, and understanding its underlying mechanisms remains a primary focus for biologists. Increasingly, empirical studies are helping explain the role of ecology in generating biodiversity. Adaptive radiations are often propelled by selective fitness tradeoffs experienced by individuals that invade new habitats, resulting in reproductive isolation from ancestral conspecifics and potentially cladogenesis. Host specialist insects are among the most speciose organisms known and serve as highly useful models for studying adaptive radiations. We are just beginning to understand the pace and degree with which these insects diversify. The apple maggot, Rhagoletis pomonella, is a well-studied insect whose eastern and southern populations are models for ecological speciation. Recently (40–65 ya), the fly has invaded the Pacific Northwestern United States through human-transported apples infested with larvae. There, populations of R. pomonella have rapidly colonized two novel hawthorn hosts whose fruiting times bracket apple’s (early-season native Crataegus douglasii and introduced C. monogyna, which fruits late in the season). The recent introduction might initiate host shifts, providing opportunities to examine the pace and mechanistic means with which host races (an evolutionary stage preceding speciation) become established. Here, I demonstrate that host-associated populations at a site in southwest Washington are partially allochronically isolated from one another, and life cycles temporally match with natal host fruit ripening times in sympatry. If spatially widespread, these temporal barriers could result in reproductive isolation and possibly cladogenesis. Implications of these findings reach beyond academic import, as R. pomonella is expanding not only its host range, but its geographic range is encroaching upon central Washington, the site of a multi-billion dollar per year apple-growing industry.