Investigation of the fate of dietary flavonols in humans and rats using HPLC-MS2 techniques

There is a growing evidence of the potential health benefits of a diet rich in fruits and vegetables. National nutritional guidelines advise the consumption of at least five portions (400 g ) of these foods per day with the goal being a reduction in the levels of coronary heart disease (CHD) strokes and certain cancers. The beneficial properties of fruit and vegetables may be ascribed, in part to the presence of antioxidants and recent attention in this regard has focused on phenolic and polyphenolic compounds. These compounds are present in a wide variety of commonly consumed foods and beverages. Onions are a rich source of the polyphenolic flavonol quercetin-4′-glucoside. For this compound to have some health effects it must be absorbed and reach target organs in a concentration and form where they can exert an effect. To-date interest has focussed on the levels of the intact quercetin aglycone circulating in plasma and excreted in urine. However, it is now known that quercetin does not circulate in the plasma as the parent compound or the aglycone. However, at the outset of this project, the exact form(s) and concentration of metabolites circulating in plasma were unknown. The need to know what compounds are actually circulating, and at what concentration, is important if in vitro studies are to be made into the mechanisms by which quercetin could, potentially, exert a health benefit. The reasons why these issues have not been addressed are due to a number of factors. The main methodology used in studies into absorption, distribution, metabolism and excretion or (A.D.M.E) as it is know in the drug industry, is by use of chromatography coupled to various detection systems. This can range from a simple isocratic single pump linked to a single wavelength absorbance detector, to a gradient pumping system with an autoinjector linked in series to a diode array absorbance detector and mass spectrometer. The latter instruments, although initially expensive are now becoming more affordable. The original methodology used to determine the level of quercetin in plasma involved hydrolysis of the quercetin conjugates back to the aglycone. The information, which is lost by using this hydrolysis method, is vital if we are to gain a better understanding of the A.D.M.E process. There have been a large number of feeding studies carried out using onions or the flavonol contained in them. However, very little additional information was gained after the initial investigations. The objectives of the studies presented in this thesis were to develop methodology to identify and quantify the major metabolites of quercetin in man after ingestion of onions. This would initially require the use of radiolabelled [2-14C]quercetin-4´-glucoside fed to rats to facilitate the development of the method. Having successfully developed methods that would work both in rats and in man, it was of great interest to establish the fate of the complete dose of [2-14C]quercetin-4´-glucoside in rats. In Chapter 2 radiolabelled quercetin-4´-glucoside was used as a tracer to follow the metabolism of the compound as it was acted on by the digestive system of the rat. After 1 h 93% of the ingested dose was recovered in the gastrointestinal tract (GIT). Analysis using HPLC with a photodiode array (PDA) detector in series with a radioactivity monitor connected to an electrospray ion trap mass spectrometer facilitated the separation, quantification and partial identification of 18 out of 19 metabolites. The 1 h sample was part of a larger study that investigated the fate of the radiolabelled compounds up to 5 h after dosing. The latter samples formed part of another study not reported on in this thesis. Having developed the methodology, using the radiolabelled compound, it was then applied to a feed of onions to healthy human volunteers to determine if metabolite detection, identification and quantification could be carried out without the use of the radioactive tracer. In Chapter 3 plasma samples collected 1 h after a feed of onions and urine collection from 0-4 h post feed were used to test if the method could be transferred to a non labelled assay. A total of 22 metabolites plus the parent compound were identified. The metabolic profile of the plasma and urine showed marked differences, again pointing to major post absorption metabolism. The successful transfer of the method from the initial radiolabelled study to the onion feed allowed pharmacokinetic data to be obtained from all plasma samples taken over a 24 h period, along with the 0-24 h urine samples. In Chapter 4 it was seen that the metabolites are both rapidly absorbed and excreted, with plasma levels returning almost back to baseline by 6 h. The total excretion in urine accounted for 4.5% of the ingested dose. These results were controversial, as the pioneer of this field had published that the elimination half life of quercetin was of the order of 18 h. The differences between the two methods employed are discussed in Chapters 3 and 4. The fact that only 4.5% could be accounted for in this study, which was in agreement with other studies, leaves the question of what happens to the other 95.5%. It is possible that the potential health benefit attributed to this compound may have nothing to do with the parent compound but could be coming from something in the other 95.5%. Studies using patients who have undergone an ileostomy have been used to provide further information into what happens to the majority of the dose. By collecting the ileal fluid after a flavonol feed the amount of intact compound can be measured in ileal fluid (Hollman et al., 1995b; Walle et al., 2000). This work and some results from a similar trial study are discussed in Chapter 4, with regard to the process of metabolite absorption and formation. The only way to follow the parent compound throughout its passage through the body is by use of a labelled compound. In Chapter 5 a second feed of [2-14C]quercetin-4´-glucoside, which focuses on the overall fate of the compound, has samples collected for up to 72 h. The fate of the dose was monitored both in terms of the level of radioactivity excreted and found in the tissues and also the identity of the radioactive compounds detected in these samples. In Chapter 5 the results from this study and what impact they could have on quercetin’s potential ability to be the compound responsible for the health benefits are discussed

Importance of complete assessment in the work-up of late onset mania

A female, age 78, with generalized anxiety disorder (GAD), history of major depression, and hypothyroidism presents for mood and anxiety concerns. Her mood is depressed, and sleep, appetite, energy, and concentration are poor. She recently saw a geriatric psychiatrist and described no past manic episodes, psychotic symptoms, or family history for bipolar disorder. No one has concerns about her cognition. She began levothyroxine 150 mcg 3 weeks ago for newly diagnosed hypothyroidism. On exam, she is talkative, overinclusive, has almost pressured speech, labile mood, and lid lag. Neuropsychology testing, CBC, and CMP are normal. TSH is 0.173. She is diagnosed with GAD exacerbated by hyperthyroidism due to over-replaced thyroid hormone causing a hypomanic syndrome. Possibly she was hyperthyroid prior to burnout and recent hypothyroid state, explaining the temporality of her manic symptoms. She reports feeling better at follow-up after medication adjustment. Late-onset mania is a (hypo)manic syndrome in a person 50 or older without a previous history of mania3. 5-10% of patients are 50+ years when they experience their first manic episode of bipolar disorder2. However, (hypo)manic syndromes can also be due to vascular etiology, dementia, medications, renal failure, and thyroid derangement. One study reports a 2.8% prevalence of organic cause of mania in those \u3e65 compared to 1.2% prevalence in those Almeida, O. P., & Fenner, S. (2002). Bipolar disorder: similarities and differences between patients with illness onset before and after 65 years of age. International psychogeriatrics, 14(3), 311–322. Arnold, I., Dehning, J., Grunze, A., & Hausmann, A. (2021). Old Age Bipolar Disorder-Epidemiology, Aetiology and Treatment. Medicina, 57(6), 587. Sami, M., Khan, H., & Nilforooshan, R. (2015). Late onset mania as an organic syndrome: A review of case reports in the literature. Journal of affective disorders, 188, 226–231.https://digitalcommons.unmc.edu/emet_posters/1036/thumbnail.jp

Active Learning for Active Minds: A Conversation with Learning Leaders

17 USC 105 interim-entered record; under review.The article of record as published may be found at https://cimsec.org/active-learning-for-active-minds-a-conversation-with-learning-leaders/U.S. Government affiliation is unstated in article text

Probability distributions for economic surplus changes: the case of technical change in the Australian wool industry

Mullen, Alston and Wohlgenant (1989) (MAW) examined the distribution of the benefits of technical change in the Australian wool industry. Their conclusions are revisited by examining the probability distributions of changes in the welfare measures, given uncertainty about their model parameters. Subjective probability distributions are specified for the parameters and correlations among some of the parameters are imposed. Hierarchical distributions are also used to model diverse views about the specification of the subjective distributions. A sensitivity elasticity is defined through the estimation of a response surface to measure the sensitivity of the estimated research benefits to individual parameters. MAW’s conclusions are found to be robust under the stochastic approach to sensitivity analysis demonstrated in this article.Livestock Production/Industries,

Chameleons bake bigger pies and take bigger pieces: strategic behavioral mimicry facilitates negotiation outcomes

Two experiments investigated the hypothesis that strategic behavioral mimicry can facilitate negotiation outcomes. Study 1 used an employment negotiation with multiple issues, and demonstrated that strategic behavioral mimicry facilitated outcomes at both the individual and dyadic levels: Negotiators who mimicked the mannerisms of their opponents both secured better individual outcomes, and their dyads as a whole also performed better when mimicking occurred compared to when it did not. Thus, mimickers created more value and then claimed most of that additional value for themselves, though not at the expense of their opponents. In Study 2, mimicry facilitated negotiators’ ability to uncover underlying compatible interests and increased the likelihood of obtaining a deal in a negotiation where a prima facie solution was not possible. Results from Study 2 also demonstrated that interpersonal trust mediated the relationship between mimicry and deal-making. Implications for our understanding of negotiation dynamics and interpersonal coordination are discussed

Influence of Solvent and Molecular Weight in Wrinkle Formation in Spin-cast Polystyrene Thin Films

The surface morphology of polystyrene thin films formed from various molecular weight polystyrene and solvent conditions is studied. When spin-cast from tetrahydrofuran (THF) wrinkles are formed at the extremities that have periodicity with wavelengths in the μm range and amplitudes in the nm range but varies with molecular weight. A mixed solvent system consisting of THF and dimethylformamide (DMF) leads to periodic structures only with THF-rich compositions. THF and DMF have similar properties relevant to spin-casting: density, surface tension, molecular weight, and viscosity but different boiling points and room temperature vapor pressures, demonstrating that formation periodicity requires a volatile solvent. The formation of the surface structures is attributed to the Marangoni effect and the film thicknesses and wave parameters are shown to be consistent with literature models

Acute kidney injury prediction in cardiac surgery patients by a urinary peptide pattern: a case-control validation study

Background Acute kidney injury (AKI) is a prominent problem in hospitalized patients and associated with increased morbidity and mortality. Clinical medicine is currently hampered by the lack of accurate and early biomarkers for diagnosis of AKI and the evaluation of the severity of the disease. In 2010, we established a multivariate peptide marker pattern consisting of 20 naturally occurring urinary peptides to screen patients for early signs of renal failure. The current study now aims to evaluate if, in a different study population and potentially various AKI causes, AKI can be detected early and accurately by proteome analysis. Methods Urine samples from 60 patients who developed AKI after cardiac surgery were analyzed by capillary electrophoresis-mass spectrometry (CE-MS). The obtained peptide profiles were screened by the AKI peptide marker panel for early signs of AKI. Accuracy of the proteomic model in this patient collective was compared to that based on urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) ELISA levels. Sixty patients who did not develop AKI served as negative controls. Results From the 120 patients, 110 were successfully analyzed by CE-MS (59 with AKI, 51 controls). Application of the AKI panel demonstrated an AUC in receiver operating characteristics (ROC) analysis of 0.81 (95 % confidence interval: 0.72–0.88). Compared to the proteomic model, ROC analysis revealed poorer classification accuracy of NGAL and KIM-1 with the respective AUC values being outside the statistical significant range (0.63 for NGAL and 0.57 for KIM-1)

"Shackles of Civilization": Race and American Imperialism in Haiti, 1915-1934

The United States, in its administration of Haiti from 1915 to 1934 effectively exported pre-existing ideas about the inferiority of non-white peoples to the island republic. The American occupation failed to create a functional democratic republic because the administrators focused upon material and infrastructure improvements while not implementing social, civic, and institutional changes conducive to democracy. The intervention was prompted by financial motivations and fear of a German takeover of Haiti, but the protracted military occupation and administration of the island quickly grew into a colonization project never fully supported by either the Haitian or American ruling classes and vociferously resisted by the Haitian commoners. Once Haiti was under American control, the Marines engaged in five years of guerrilla warfare against the cacos, or bandit-soldiers. News of war crimes committed by the Marines prompted an inquiry by the United States Senate which resulted in the appointment of Marine Corps Commandant John Russell as High Commissioner. The 1920s saw the High Commissioner act as a military dictator, ruling through the Haitian president as a client and only answering to the American Secretary of State. The Commissioner focused upon physical infrastructure improvement and an educational system focused upon vocational training and manual labor rather than the liberal-arts curriculum favored by the Haitian ruling class. The educational system was not designed for a nation prepared for self-government but a nation being groomed for perpetual dependency upon the United States. The educational system imposed by the United States led to nationwide riots and a massacre of protesters by Marines in Aux Cayes in 1929. The shock and scandal of the violence led the U.S. President to appoint a commission led by Cameron Forbes to organize the withdrawal of the United States and R.R. Moton to oversee the reorganization of the Haitian education system. Upon withdrawal of U.S. troops in 1934, Haiti was left with no significant lasting institutions except the Haitian gendarmerie, which furnished the power base for the post-Occupation dictatorships. Haiti remains an unstable country in the twenty-first century, dependent upon foreign aid for survival. The fragility of Haiti's democracy and its dependence upon foreigners are legacies of the Occupation period