No description available.

Graduation date: 1950

This study investigated the ecological characteristics of the box jelly, Carybdea rastonii, in the waters off eastern Taiwan from 2007 to 2009. We started from field net sampling and some basic morphometric analysis to study its population dynamics, and continued with gut-content analysis, digestion rate and respiration rate experiments to estimate on the energy budget of C. rastonii, as well as its ecological significance in this region. We found the spots around the margin of pedelium through all samples, suggesting a stable morphological character of this species. Some specific behaviors were also observed, including the vertical movement after feeding and resting behavior (either lying on the bottom or drifting with the flow) during nighttime. Diagonal bell width (DBW) of C. rastonii was used as the size parameter, ranging from 4.17 to 46.39 mm in the collected samples, and was of significant positive-correlation with volume, wet weight, dry weight, and the length of statolith, suggesting DBW as a good indicator in age-determine. Weekly population structures indicated at least two peaks of strobilation occurring during the sampling period in 2008. Further analysis on the potential impact from environmental perturbation, by comparing the values of DBW with the length of the specimens taken immediately before and after typhoon attack, suggested a potential starvation effect on the local population. Results from gut-content analysis indicated a high percentage of empty guts (63.09%) in the checked specimens, having crustacean as the most dominant prey (up to 68.79%), and a diet shift to more larval fish from larger individuals. Based on the results from gut-content analysis and digestion rates on different types of prey, the estimated population carbon intake of C. rastonii (at 28 ind m-3) was about 20.77 mg m-3 d-1. However, results from respiration rate experiments suggested a higher basic metabolic demand of the box jelly (up to 0.126£gmol O2 h-1 mgDW-1, at 27¢J), which is significantly higher than other scyphomedusae of similar temperature range. According to the need of metabolism, the demand of carbon intake was estimated at 39.40 to 47.77 mg C m-3 d-1, an amount that might be under estimated for this voracious predator. Based on the estimated high values from both feeding and physiological demand, compared to the much lower primary production rate of 7.6 mg C m-3 d-1 in the Kuroshio waters, we concluded that C. rastonii as an important predator in this region, especially during its blooming seasons.

Graduation date: 1938

Graduation date: 1944

No description available.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / Culturing stem cells is usually done on tissue-culture treated plastic. Over time the cells change their gene expression and start to differentiate. Porcine umbilical cord (PUC) stem cells express the embryonic transcription factors Oct4, Nanog and Sox2 and changes in their expression may be useful for to evaluating culture-induced changes in the cells. We developed an extract of porcine Wharton’s jelly matrix (JMX) that may provide some characteristics of the stem cell niche located in the umbilical cord. Our extract used whole cords and enzyme digestion to simplify preparation of the product. We compare cells cultured on plastic to those grown on thin and thick gels of JMX in four experiments. In Exp 1a and b, growing PUCs on a thick JMX coating for 3(1a) or 4(1b) d increased the number of cells at the end of culture (P < 0.05) with minimal effects on gene expression. In Exp 2 we compared PUCs grown on thin and thick layered JMX with added collagen (+C) and to control cells. The JMX layers caused the cells to adopt a small, round shape and to form clumps or colonies during culture. No differences (P > 0.10) were seen between thin10 +C and control wells for viable and total cell counts but thick layered +C resulted in decreased numbers of viable cells compared to thin + C (P < 0.10) and control wells (P < 0.05). In a follow up experiment (Exp. 3) growing the PUCs mixed within, rather than plating on top of, a thick layer of JMX + C caused marked morphological changes with dense 3-dimensional structures formed. Exp 4 compared JMX allowed to gel for 10 (Thin10 +C) or 60 (Thin60 +C) min before the non-gelled fraction was removed. There were no effects on cell numbers at the end of culture (P > 0.10) but Sox2 expression was increased in Thin60 +C compared to controls on plastic (P < 0.05) and Thin10 +C (P < 0.10). In summary, JMX extracts change cell morphology and in some formats increased cell proliferation and may increase Sox2 expression. Further investigation is needed to fully understand the effects of JMX on PUCs.

Master of Science / Department of Animal Sciences and Industry / Duane L. Davis / Cell isolation method may have effects on the characteristics of the cells isolated from porcine umbilical cords. As stem cells age or approach senescence, it is hypothesized that their properties change. We expect that isolation method and age of cells will have effects on the phenotype of porcine umbilical cord (PUC) cells during in vitro expansion. We investigated the effects of three isolation methods on PUC population doublings, ability to produce colony forming units (CFU), and amount of ganglioside GD2 (GD2) expression over eleven passages. Isolation methods were explant (Exp) in which the Wharton's Jelly was removed from cords, minced and plated, enzyme digest (Dig), and stomacher assisted enzyme digestion (Stom). Cell isolates were analyzed for GD2 expression, CFU, and population doublings at early (3), middle (7), and late (11) passage. The Exp method produced greater (P<0.05) population doublings and more (P<0.05) CFU at passage 7. Explant isolates also were numerically more likely to survive to passage 11 (9/9 isolates vs 5/9 for Dig and 7/9 for Stom). In contrast, the percent cells expressing GD2 was greater (P<0.05) for Stom isolates than Exp isolates at passage 11. There were no trends for increased passage number to decreased population doubling, CFU formation, or percent GD2 positive cells. In summary, our results indicate that the Exp isolation method produced the greatest number of population doublings over 11 passages and there were minimal effects of isolation method on CFU and GD2 expression. Although Exp may be more difficult to scale up to isolate all of the PUCs in a cord, it provided greater in vitro expansion than the enzyme methods in our experiment and may provide the most cells for biotechnological and biomedical applications.

Orientador: Regildo Marcio Gonçalves da Silva / Banca: Dario Abel Palmieri / Banca: Valter Henrique Marinho dos Santos / Resumo: O estresse oxidativo está correlacionado ao aparecimento de doenças, e pode ser intensificado devido à exposição a fatores ambientais, como estresse, abuso de drogas, radiação solar, poluição entre outros. Estudos com vegetais têm demonstrado que os mesmos podem conter compostos antioxidantes passíveis de remediar ou prevenir tais complicações. Nesse contexto o presente trabalho avaliou a atividade antioxidante, antiglicante, fotoprotetora e verificou-se a presença de compostos polifenólicos dos extratos aquoso, etanólico e hidroalcoólico de frutos de Chrysophyllum cainito L, Hancornia speciosa Gomes. e P. glomerata Berg., além disso foram produzidas e analisadas geleias desses frutos. Compostos fenólicos foram determinados por técnicas espectrofotométrica e HPLC (High performance liquid cromatography). Foi verificada a presença de compostos fenólicos, incluindo flavonoides, para todos os de frutos avaliados, com destaque para os extratos de C. cainito (casca), que apresentou os maiores valores com o extrato hidroetanólico dessa espécie. Quanto a atividade antioxidante, novamenta a espécie de C. cainito obteve os mais valores entre os resultados para os diferentes testes realizados, sequestro do radical livre DPPH, potencial redutor de ferro (FRAP - ferric reducing antioxidant power), inibição da peroxidação lipídica (TBARS - thiobarbituric acid reactive substances), e sequestro do NO, entretanto os demais extratos avaliados para as outras espécies, H. speciosa e P. glomerata... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Oxidative stress is correlated with the onset of disease, and can be intensified due to exposure to environmental factors such as stress, drug abuse, solar radiation, pollution, among others. Studies with vegetables have shown that they may contain antioxidant compounds likely to remedy or prevent such complications. In this context, the present work evaluated antioxidant, antiglican and photoprotective activity and verified the presence of polyphenolic compounds of the aqueous, ethanolic and hydroalcoholic extracts of fruits of Chrysophyllum cainito L., Hancornia speciosa Gomes. and P. glomerata Berg. in addition, jellies of these fruits were produced and analyzed. Phenolic compounds were determined by spectrophotometric techniques and HPLC (High performance liquid chromatography). It was verified the presence of phenolic compounds, including flavonoids, for all evaluated fruits, especially the extracts of C. cainito (peel), which presented the highest values with the hydroethanolic extract of this species. As for the antioxidant activity, again the C. cainito species obtained the highest values among the results for the different tests performed, DPPH free radical sequestration, ferric reducing antioxidant power (FRAP), inhibition of lipid peroxidation (TBARS - thiobarbituric acid reactive substances), and NO scavenging. However, the other extracts evaluated for the other fruit species, H. speciosa and P. glomerata also obtained significant results. These results Indicate antioxidant potential for the fruits of these species tested and that are possibly related to the presence of phenolic compounds. Only the hydroethanolic (70%) extract of P. glomerata indicated antiglication activity at the concentration of 10mg.mL-1. As for the jellies produced, the C. cainito jelly also obtained prominent results for both nutritional and functional constituents, but the P. glomerata one presented... / Mestre

Anaplastic Lymphoma Kinase (ALK) was discovered in 1994, as a chromosomal translocation, t(2;5)(p23;q35), often seen in Anaplastic Large Cell Lymphomas (ALCL). Since then ALK has been extensively studied in this disease as well as in different model organisms. Due to its expression pattern within the central and peripheral nervous system ALK has been implicated in neuronal development. This hypothesis has been further strengthened by studies from Drosophila which have shown Alk to have an important role in optic lobe development. A recently described ALK mouse knockout model do not indicate an essential role for ALK in development, although a potential role within the central nervous system was strengthened. This since ALK-/- animals has an increased number of progenitor cells in the hippocampus and display altered behavior. The overall aim of the studies included in this thesis was to elucidate the function of ALK in the mouse. As a first step toward this goal we conducted an analysis of ALK mRNA and protein expression patterns during development. The strong expression of ALK in neuronal structures supports a role for ALK in neuronal development during embryogenesis. To further investigate the function of ALK in a physiological context we have developed two different ALK knockout strains, the ALK Kinase knockout (KO) and the ALK exon1 KO. The only visible phenotype in these strains is a reduction of total body weight which is apparent in the ALK-/- population when compared to wild type littermates. This size difference seems to take place after birth and is not due to an alteration in food consumption. We have also extensively studied the ALK Kinase KO with respect to gross development, the gastrointestinal canal and the olfactory system. ALK displays a very distinct expression pattern within the gastrointestinal canal being confined to enteric neuron precursors during embryogenesis and enteric nerves in the adult tissue. From these studies we conclude that ALK is not needed for development and viability in mice although it does play a role in regulation of body weight via a presently unknown mechanism. In addition, we have investigated the relationship between the Drosophila and mouse ALK receptor by examining the ability of the Drosophila Alk ligand Jelly-Belly, Jeb, to activate mouse ALK. Using different in vivo and in vitro techniques, we have shown that activation of mouse ALK cannot be accomplished by Drosophila Jeb. From this study we draw the conclusion that during development ligands for the Drosophila and mouse ALK has diverged to a level at which they can no longer substitute for each other.