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Tumourigenic cells utilize aberrant metabolic process that supports the biosynthetic requirements for hyperproliferation, survival and prolonged maintenance characterised by glucose metabolism to lactate dehydrogenase independent of oxygen availability (Warburg effect). In addition, tumourigenic cells exert increased glycolytic- and glutaminolytic activity in order to provide increased quantities of adenosine triphosphate. The aim of this research project was to investigate the influence of glutamine deprivation on proliferation, morphology, oxidative stress, mitochondrial membrane potential, cell cycle progression, antioxidant defences, deoxyribonucleic acid (DNA) damage, energy status, cell survival signaling and cell death induction in tumourigenic- and non-tumourigenic breast cell lines. In this study it was found that glutamine deprivation results in differential antiproliferative activity where the MCF-7 cell line was the most affected with decreased cell growth to 61% after 96 h of glutamine deprivation. Aberrant redox activity was most prominently observed in the MCF-7 cell line accompanied with biphasic mitochondrial membrane potential- and reactive oxygen species production. The MCF-7 cell line showed significant mitochondrial membrane depolarisation after 24 h and 96 h deprivation from glutamine (1.5- and 1.37 fold). Cell cycle progression analysis illustrated an increase in the amount of cells present in the S-phase in the MCF-7 cell line after 72 h of glutamine deprivation. The MDA-MB-231 cell line resulted in a significant increase in cells occupying the G2/M phase after 24 h of glutamine deprivation. Glutamine deprivation in the BT-20 cell line resulted in a significant increase in cells occupying G1 phase after 72 h of glutamine deprivation. The MCF-7 cell line demonstrated the least amount of viable cells when analysing apoptosis induction, when compared to the MDA-MB-231-, MCF-10A- and BT-20 cell lines after glutamine deprivation suggesting that the MCF-7 cell line is the most affected cell line. Analysis of antioxidant mechanism via superoxide dismutase (SOD) inhibition illustrated increased SOD activity in the MCF-7 cell line (9.1%) after 72 h of glutamine deprivation. Evaluation of catalase protein concentration indicated that the MCF-7 catalase expression increased to 1.28 fold after 24 h of glutamine deprivation when compared to cell propagated in complete growth medium. DNA damage was demonstrated by visualising the presence of fluorescent 8-hydroxydeoxyguanosine and showed that the MCF-7 cell line presented with significant 8-hydroxydeoxyguanosine staining. Survival signaling was also evaluated through visualising extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K) signaling which demonstrated increased ERK activation in the non-tumourigenic MCF-10A cell line and decreased PI3K activation. This study provides evidence that there are differential- and time-dependent responses in breast tumourigenic cells versus non-tumourigenic cells, to glutamine deprivation thus unraveling the crosstalk between glutamine deprivation, oxidative stress and cell death and different cell types will enable us to better understand the basics of tumour cell metabolism and thus develop therapeutics that provide promising pre-sensitization potential for chemotherapeutic agents. / Dissertation (MSc)--University of Pretoria, 2020. / Physiology / MSc / Unrestricted

Seit Anfang der Siebzigerjahre werden weltweit in Rinderbetrieben in vielfältigen Variationen und Anwendungen Stoffwechseluntersuchungen durchgeführt. Das Hauptaugenmerk lag dabei stets auf Seiten der Energie- und Mineralstoffversorgung. Die Superoxid-Dismutase (SOD) fand hier bislang keine Berücksichtigung. Ziel der vorliegenden Untersuchung war es, die SOD-Aktivität in Stoffwechsel-untersuchungen bei klinisch gesunden Kühen mit ein zu beziehen sowie den Einfluss von Laktation und Jahreszeit zu prüfen. Versuchsanordnung: Insgesamt wurden bei 125 SB/HF-Kühen (7990 kg fettkorregierte Milch/Jahr) folgende drei Gruppen analysiert: Gruppe 1: Im Verlauf eines Jahres wurden im Abstand von 6 Wochen jeweils 10 gesunde Kühe, die sich alle 1-2 Wochen post partum (pp) befanden, untersucht. Zusätzlich wurden die Stall- und die Außentemperaturen berücksichtigt. Gruppe 2: Zur Kontrolle des Laktationsverlaufes wurden 10 Kühe zum Zeitpunkt 4-5 Wochen ante partum (ap), 1 Woche ap, 1-2 Wochen pp, 4 Wochen pp und 8-12 Wochen pp untersucht. Gruppe 3: Um jahreszeitlich bedingte Schwankungen des Stoffwechsels und der SOD-Aktivität in Gruppe 2 auszuschließen, wurden an einem Entnahmetag jeweils sieben verschiedene Kühe zum Zeitpunkt 4-5 Wochen ap, 1 Woche ap, 1-2 Wochen pp, 4 Wochen pp, und 8-12 Wochen pp geprüft. Die Tiere aller drei Gruppen wurden nach der klinischen Untersuchung hämatologisch sowie klinisch-chemisch (SOD, β-Hydroxybutyrat (BHB), Glucose, Cholesterol, Bilirubin, Glutamat-Dehydrogenase (GLDH), Aspartat-aminotransferase (ASAT), Creatinkinase (CK), Protein, Albumin, Harnstoff, Calcium, anorganisches Phosphat, Magnesium, Natrium, Kalium, Chlorid, Eisen) getestet. Auch die Fütterung fand durch Anfertigung einer Rationsberechnung Berücksichtigung. Ergebnisse: Die Ergebnisse der Stoffwechseluntersuchungen und der SOD-Aktivität im Jahresverlauf (Gruppe 1) deuten auf eine verminderte Futteraufnahme in den Sommermonaten infolge Hitzestresses hin. Vor allem ein Absinken der Harnstoff-, Glucose- (positive Korrelation zur SOD-Aktivität), Phosphat- (positive Korrelation zur SOD-Aktivität) und Cholesterolkonzentrationen bei gleichzeitig ansteigenden BHB- (negative Korrelation zur SOD-Aktivität) und Bilirubinkonzentrationen weisen auf eine negative Energiebilanz in diesen Monaten hin. Die Calcium- und Magnesiumkonzentrationen liegen bei allen Tieren im unteren Referenzbereich. Die SOD-Aktivität klinisch gesunder Kühe im Jahresverlauf beträgt 501 bis 978 U/ml Erythrozytenlysat (Interzentilbereich). In Gruppen 2 und Gruppe 3 sind ebenfalls deutliche Schwankungen der Stoffwechselparameter Protein, Harnstoff, Bilirubin, Glucose, BHB und Cholesterol zu beobachten, wobei die stärksten Schwankungen im Zeitraum 1 Woche ap bis 4 Wochen pp vorhanden sind. Auch dies ist durch die reduzierte Futteraufnahme peripartal sowie steigende Futteraufnahme in der Frühlaktation zu erklären. Die SOD-Aktivität der Kühe aus Gruppe 2 zeigt die entsprechenden Schwankungen mit niedrigen Aktivitäten 4-5 Wochen ap bis 1-2 Wochen pp und einen deutlichen Anstieg bis 4 Wochen pp. Die Calcium- und Magnesiumkonzentrationen befinden sich auch in dieser Gruppe im unteren Referenzbereich. In der Gruppe 3 fällt bei den Kühen 4 Wochen pp eine deutliche Stoffwechselbelastung mit erhöhten Bilirubin- und BHB-Konzentrationen sowie ASAT- und GLDH-Aktivitäten auf. In dieser Gruppe sind die Calcium- und Magnesiumkonzentrationen physiologisch. Die SOD-Aktivitäten differieren nur gering mit einer tendenziell höheren Aktivität 4 Wochen pp. Insgesamt fallen im Vergleich zu Gruppe 1 und 2 deutlich höhere SOD-Aktivitäten zwischen 835 und 1758 U/ml Erythrozytenlysat (Interzentilbereich) auf, welche mit den höheren Calcium- und Magnesiumkonzentrationen in Beziehung stehen können. Schlussfolgerungen: Schwankungen von Stoffwechselparametern im Jahres- und Laktationsverlauf betreffen vor allem fütterungsabhängige Parameter. Die SOD-Aktivität verhält sich entsprechend dieser fütterungsabhängigen Parameter mit niedrigerer Aktivität bei längeren Belastungsphasen sowie im geburtsnahen Zeitraum. Statistisch gesicherte Korrelationen ergaben sich mit folgenden fütterungs-abhängigen Parametern: im Jahresverlauf mit BHB, Glucose und anorganischem Phosphat, im Laktationsverlauf in Gruppe 2 mit BHB, Cholesterol, Protein, Glucose, Magnesium und Milchharnstoff und in Gruppe 3 zu BHB und Magnesium. Die Analyse der SOD-Aktivität bereichert die Informationen bei Stoffwechselkontrollen sinnvoll.

Turfgrass establishment on sand-based rootzones is routinely accomplished by using sod produced on a fine-textured native soil. As a result, soil layering occurs, potentially causing initial reduction in water infiltration, rooting, aeration, and overall turfgrass quality. This research was aimed at determining the feasibility of applying sand over existing native soil to produce hybrid bermudagrass (Cynodon dactylon [L.] Pers. x C. transvaalensis Burtt-Davy) sand-based sod. Factors evaluated were visual quality and scalping. Treatments were harvested and transplanted to a sand-based research green where handle-ability, tensile strength, and infiltration were also evaluated. Results indicate aerify and topdress treatments showed higher quality pre-harvest. Control and 25 mm treatments were best in terms of harvesting, handle-ability, and sod tensile strength. Infiltration data indicated no significant differences between treatments. These outcomes along with further analysis could provide sod producers with a valuable product for use on sand-based rootzones.

Cerium is the most abundant of the rare earth metals, found on average at a level of 66 parts per million in the earth's crust. The unique redox properties of cerium and cerium oxide nanoparticles have led to its use in a wide variety of industrial and commercial uses such as oxygen sensors, fertilizers and as a catalyst to remove toxic gases in automobile exhaust. The use of cerium has also garnered interest in the nanotechnology field. Nanoceria has been generated in its oxide form as nanoparticles and nanorods. Recently, nanoceria has been shown to protect against oxidative stress in both animal and cell culture models. Although not fully understood, this observed protective effect of nanoceria is believed to be the result of recently identified SOD mimetic activity. Currently there is little understanding as to how nanoceria is capable of scavenging radicals or what properties makes nanoceria an effective SOD mimetic. Our data shows strong evidence that the oxidation state of nanoceria is directly related to its reported SOD mimetic activity. As such, future studies of nanoceria should be mindful of the oxidation state of nanoceria preparations as only nanoceria with a high concentration of cerium (III) have shown effective SOD mimetic activity. In addition to the characterization of nanoceria and its SOD mimetic activity, we have evidence that free cerium is capable of generating radicals and damaging DNA in vitro in the presence of hydrogen peroxide. These data strongly suggests that the rare earth inner-transition metal cerium is capable of generating hydroxyl radicals via a Fenton-like reaction. Based on these results the use of free cerium salts should be monitored to limit environmental exposure to cerium. Altogether our data would suggest that cerium by virtue of its unique redox chemistry is quite capable of accepting and donating electrons from its surroundings. In its free form cerium is able to redox cycle easily and can generate radicals. However, paradoxically nanoceria may not easily redox cycle due to the bound lattice structure of the particle. The unique nature of nanoceria and cerium leads to a unique circumstance where nanoceria is a radical scavenger while free cerium generates radicals. As such, further investigation is needed to insure that leeching or cerium from nanoceria does not abrogate any potential benefit nanoceria may provide.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22849号 / 農博第2432号 / 新制||農||1082(附属図書館) / 学位論文||R2||N5309(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 佐藤 健司, 教授 澤山 茂樹, 教授 菅原 達也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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<p>  </p> <p>Kentucky bluegrass is the most common cool-season turfgrass grown in the northern US. <br> The fact that Kentucky bluegrass requires s high quantity of fertilizers, pesticides, and irrigation to produce high quality turf has led to environmental concerns among policymakers, researchers, and consumers. To address this concern, turfgrass breeders have developed improved cultivars of low-input turfgrass species that aim to improve the sustainability of US lawns (Ghimire et al., 2019). For instance, tall fescue [(<em>Festuca arundinacea </em>Schreb.; syn. <em>Schedonorus arundinaceus</em> (Schreb.) Dumort., nom. cons.] and fine fescues (<em>Festuca </em>spp.) may represent viable options for residential and commercial buildings due to their outstanding performance under lower amounts of inputs such as irrigation, pesticides, and fertilizers (Watkins et al., 2011). Thus, adopting improved cultivars of low-input species may be a step towards reducing the use of inputs in landscapes (Simmons et al., 2011; Pooya et al., 2013). Yet, the production of low-input turfgrasses in the northern US is slow and limited, which leads to marketing and education obstacles that support their adoption. Thus, understanding factors that influence sod buyers to purchase low-input turfgrasses is imperative to increase the market share and the adoption of these turfgrasses. </p> <p>This study investigated the factors influencing sod buyers to purchase low-input turfgrass in the northern US, using tall fescue and fine fescue as low-input sod species. Using a logistic regression model, we assessed the determinants of low-input turfgrass purchase among sod buyers (i.e., athletic facilities, landscape contractors, garden centers, general contractors, lawn care, golf courses, and municipal parks). The logit model assumed the adoption decision to be driven by the buyers’ perception of the utility of buying low-input turfgrass species. Thus, the dependent binary variable Y equals 1 if the firm purchased tall or fine fescue in 2020, and 0 otherwise. The adoption is then expressed as a function of determinants, including the firm’s characteristics, supplier characteristics, sod attributes, and buyer’s perceptions. </p> <p>Data for this study came from a 2021 web-based survey of sod buyers located in 19 states of the Northern US. A total of 200 buyers completed the survey, including landscape contractors, golf courses, general contractors, lawn care services, and landscape maintenance firms who have purchased sod in 2020. The significant mean comparisons between adopters and non-adopters showed that adopters of low-input turfgrasses purchased most of their sod through contract agreements. The main suppliers of adopters were located at a closer distance to on-site delivery than the non-adopters. The logit regression results showed that low-input turfgrass adoption was positively influenced by the number of sod suppliers and managerial experience of the sod buyer. Landscapers were more likely to purchase tall fescue and fine fescue compared to golf courses and municipal parks. We found that distance from sod supplier to on-site delivery negatively impacted the purchase of low-input turfgrasses. Similarly, Kentucky bluegrass buyers were less likely to purchase low-input turfgrass species.</p>

Composted biosolids have been shown to enhance turfgrass establishment and growth more than fertilizer alone, but few studies have investigated the production of turfgrass using uncomposted biosolids. Increasingly employed treatment methods that generate pathogen-free, low pollutant-containing biosolids are creating alternative products for use in urban settings.  Understanding the effects of these uncomposted and alternative biosolids products on turfgrass culture and soil chemical and physical properties is essential to understanding the benefits these products may provide in sod production systems. The objectives of this study were to compare processing methods, application and N mineralization rates of two biosolids products and an inorganic fertilizer control for sod fertilization on 1) agronomic parameters related to turfgrass quality, 2) the amount of soil, C and P exported at harvest, and 3) chemical and physical properties of the soil following sod harvest as an indicator of the benefits of biosolids use. The study was conducted on a sod farm in Remington, Virginia on a silt loam Ashburn-Dulles complex from 2009 to 2012. The biosolids products were applied at estimated plant available nitrogen (PAN) rates of 98 kg N ha-1  (0.5X), 196 kg N ha-1 (1.0X) and 294 kg N ha-1  (1.5X) for a tall fescue (Festuca arundinacea Schreb. \'Rebel Exeda\' \'Rebel IV\' and \'Justice\')/ Kentucky bluegrass (Poa pratensis L. \'Midnight\') mixture. One biosolids product was an anaerobically digested dewatered cake applied at 15, 30.5 and 46 wet Mg ha-1. The second biosolids product was the same cake blended with wood fines applied at 17, 34 and 51 wet Mg ha-1. The biosolids treatments were compared to an inorganic fertilizer control that supplied 196 kg N ha-1 through three applications over the production cycle. There were no differences in establishment between the cake biosolids treatments and the inorganic fertilizer control, but all of the blended biosolids were slower to establish. Only the 1.0X and 1.5X PAN rates from the cake biosolids matched the inorganic fertilizer control in producing an acceptable quality sod in ten months. Lower nitrogen uptake between the blended biosolids treatments compared to the inorganic fertilizer control and lower although acceptable sod quality ratings at harvest of the 1.0X cake biosolids indicate our PAN estimates of 30% organic nitrogen mineralization overestimated the PAN for both materials. There were no differences in sod tensile strength between the 1.5X cake biosolids and inorganic fertilizer control. There were no differences in transplant rooting strength among all treatments. After repeat applications of biosolids, the 0.5X rates did not increase soil extractable phosphorus, while the 1.0X rates steadily increased soil extractable phosphorus at. The 1.0X and 1.5X biosolids rates increased soil organic matter content, but only the 1.5X rate of cake biosolids reduced soil bulk density and mineral matter export at harvest. Overall results indicate that the cake biosolids are an acceptable fertility alternative to inorganic fertilizer, and applications of biosolids for sod production can improve soil quality. Sod growers should consider using biosolids in a rotational system to offset rising production costs and improve production field soil quality. / Master of Science