Lamb adipose tissue, representing 4 breeds, 3 sex-types and 3 weight categories, were studied to measure the variation in the flavor profile between individual animals, based on breed, sex- type and carcass weight. The flavor concentrates were prepared by steam distillation, ether extraction and fractionation. Pooled samples were prepared in the same way to measure any variations due to methodology. Gas chromatographic separation and statistical analysis, based on analysis of variance, indicated that 21 peaks out of 124 peaks showed significant differences (at 5% level or 1% level). Among these 21 peaks, 5 were affected by breed, 4 by sex-type, 8 by carcass weight and 7 peaks were influenced by the interaction of breed, sex-type and carcass weight. Variations due to breed revealed that Rambouillet lambs possessed the highest proportion of flavor peaks which showed significant differences, with Targhee lambs the second highest, Columbia the third and Suffolk- cross the lowest proportion of flavor compounds. The effect of sex-type suggested that was contributed to the highest concentration of peaks which might influence the expression of flavor. However, there was no evidence showing that the concentration of peaks for ewes was greater than that of wethers or vice versa. Differences associated with weight indicated that light animals yielded a higher concentration of flavor volatiles, medium weight lambs the second and heavy lambs the lowest concentration of volatiles. The influence of the interaction of three variables was found to be more prevalent in the combination of Suffolk-cross ewe heavy and Suffolk- cross ewe medium . Several reasons are employed to explain the deviations of some peaks present in the chromatograms of pooled samples.

BiOWiSHTM – Aqua is a blend of preserved multi-bacteria culture with the capability of denitrification. If an anaerobic nitrate rich activation procedure is used instead of the standard aerobic activation procedure, the denitrification rate is increased by 28 percent under the conditions of 30°C, 1C:1N, 200mg/L of carbon, and 200mg/L nitrogen.

<p> The extremely halophilic bacterium, Halobacterium salinarium, contains a light density satellite DNA component which is 20% of the total DNA. </p> <p> The purpose of this investigation was to study the physical characteristics of the satellite DNA by ultra- centrifugation and electron microscopic methods in an attempt to answer the following questions: "(a) Does the amount of the satellite depend on DNA isolation conditions?" "(b) What is the biological derivation of the satellite?" "(c) What is the physical size( s) of the satellite?" "(d) How many copies of the satellite occur in the"cell?" </p> <p> The results of this investigation showed that the amount of the satellite is independent of isolation conditions, and that it exists in the form of closed circular duplexes. Although the possibility that the satellite represents multiple forms of closed circular molecules could not be completely ruled out, the majority of the closed circles appeared to have lengths about 37 u, so that there might be eight copies of the satellite per bacterial genome. </p> / Thesis / Master of Science (MSc)

Call number: LD2668 .T4 1978 O72 / Master of Science

Background: Pancreatic disease is a global problem. Severe acute pancreatitis (AP) carries a 30-50% mortality. Current scoring systems fall short in predictive accuracy, sensitivity, specificity and availability. Pancreatic cancer (PC) is a leading cause of cancer-related mortality, most patients die within one year of diagnosis. Late presentation and lack of effective oncological treatment determine a desperate need to focus on early detection of the pancreatic cancer. Current biomarkers fall short in accessibility, sensitivity and specificity and ability to distinguish malignant from benign conditions. Metabolomics aims to decipher molecular signatures that will distinguish disease from controls, ultimately leading to novel targets for diagnosis and treatment. Initial studies are discovery-based, hypothesis-generating and typically aim to establish a snapshot of the metabolism of an individual by metabolite profile. Aims: Establish a prospective phenotypic and demographic database of patients with acute pancreatitis. Determine urinary and serum metabolomic profiles of AP and PC in comparison to controls and establish if metabolomic profiling can distinguish severity of each disease in order to identify potential novel bio-markers. Methods: Urine and serum samples from 73 AP, 32 PC, 62 Healthy Controls, 8 Chronic pancreatitis and 8 Benign jaundice participants were analysed using GC-MS and UPLCMS. Metabolite identification was subject to univariate and multivariate analysis (p<0.05). Results: The differentiation of metabolite profiles was most distinct with AP. There was no differentiation by AP aetiology. AP severity was distinquished by metabolite profile. Profiles of resectable patients were distinct form non-resectable PC. Fatty acids(FA), glycerophoshocholines, eicosanoids, TCA cycle intermediates and melatonin levels were altered in AP. PC was defined by altered concentrations of FAs, eicosanoids, glycerophoshocholines, sphingomyelins, folates and amino acids and peptides (e.g. glutamine). Altered levels of UFAs, neuromedins, Vitamin D3 determined stage of PC. Conclusion: Urinary and serum metabolomic signatures may provide future biomarker panels for grading AP and PC.

Background: The use of novel targeted anticancer drugs in clinical practice is rapidly increasing. As the use of these drugs increases, so does the need to develop biomarkers to optimise the drugs' clinical and cost effectiveness. The attitudes and views of all stakeholders regarding the optimal use of predictive biomarkers in guiding personalised medicine are crucial for identifying acceptable criteria of predictive biomarker tests to guide future biomarker development. To gain insight into these views, we aimed to develop and validate a survey tool that would aid in assessing attitudes of cancer physicians and patients regarding the utilisation of biomarkers in tailoring treatment according to individual patient needs. Methods: Two questionnaires (one for oncologists and one for patients) based on emerging clinical data about novel targeted anticancer agents were designed to capture information about acceptable sensitivity, specificity, invasiveness and cost of a predictive biomarker test. A hypothetical scenario was provided that described a newly developed, targeted anticancer drug that was found to be more beneficial to certain patient subgroups identified through a predictive biomarker test. Questions in the patient survey were based on the results of the oncologist survey. Results: The response rates to these surveys were 20% (n=67) for the oncologists and 59% (n=100) for the patients. The oncologists' attitudes regarding the predictive biomarker test's false negative (FN) and false positive (FP) rates varied with the level of health outcome generated by the hypothetical drug. The acceptable FN rate for predictive biomarker test results detected in the current study was similar to many current predictive biomarkers, but the FP rate considered acceptable was much lower. The majority of the patients (90%) accepted the median acceptable FN rate of 10% reported by the oncologists. A significant minority of the oncologists (27%) refused a tumour biopsy (in addition to the diagnostic biopsy) to collect samples for the purpose of predictive biomarker testing. A much higher percentage of patients (68%) refused a biopsy under such conditions. Interestingly, our data also suggest that oncologists' expectations for the outcome of therapy have changed little in recent years, while patients' expectations have increased dramatically. Conclusions: Our data suggest that oncologists and patients agree that a FN rate of 10% is acceptable. However, based on the oncologists' responses, the FP rates associated with current predictive biomarkers are far from ideal. This may reflect oncologists' pragmatic approach in the absence of alternative choices for predictive biomarker tests. However, it also suggests that future biomarker development and implementation must focus on decreasing the FP rate without increasing the FN rate. Recent results demonstrating molecular heterogeneity in tumours suggest that, considering our data on acceptable test accuracy, serial/repeated tumour biopsies may be required. However, based on the attitudes of physicians and patients reported here, such ‘biopsy-driven' clinical trials may not be acceptable, and, without further investigation or education, this may be a barrier to the successful implementation of such potentially valuable investigational strategies. These results should certainly be taken into account when planning biopsy-dependent trials, and emphasises the importance of pursuing non-invasive biomarker assays. We believe that the survey questionnaires originating from the current study are valid tools for assessing stakeholders' attitudes and views about the appropriate application of predictive biomarkers in personalised medicine.

No description available.

published_or_final_version / abstract / Zoology / Doctoral / Doctor of Philosophy

published_or_final_version / Surgery / Master / Master of Philosophy

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy