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Diagnosis of marginal zinc deficiency using current biochemical markers is unreliable due the lack of sensitivity or specificity. Metallothionein (MT) levels in various fluids and tissues have been shown to reflect zinc status, but measurement of the protein has proved difficult in plasma and white blood cells. An alternative to measuring MT protein is the assay of MT mRNA in blood cells. Northern blotting was not sensitive enough to detect basal levels of MT from human T cells. A sensitive RTPCR assay was developed which detected and measured human MT-2A mRNA in T cells. A competitive MT-2A DNA standard with an 80 base-pair deletion was constructed that co-amplified with the MT-2A mRNA during RT-PCR. After analysis of the PCR products by gel electrophoresis, the ratio of the added standard to MT-2A was used to quantify the MT-2A mRNA expression. Competitive RT-PCR was also carried out for β-actin to correct for RNA degradation and loading. Capillary electrophoresis combined with laser-induced fluorescence detection can also allow sensitive and rapid analysis of RT-PCR reactions. The RT-PCR assay was used to measure MT-2A gene expression in T cells from human volunteers in zinc deficiency studies. In a severe zinc deprivation study (>0.5 mg Zn per day) most of the samples were too degraded for accurate analysis, showing the requirement of a degradation control for quantitative RT-PCR. In a marginal zinc deprivation study, human volunteers were given a diet that was changed from 15mg Zn/day to 5mg Zn/day. After 50 days on the low zinc diet, each individual showed a decrease in T lymphocyte MT-2A mRNA levels (30-80% of baseline value). The T lymphocyte MT-2A mRNA levels increase upon zinc repletion (15mg Zn/day) after about two weeks. There were no apparent changes in plasma zinc concentration during the study. This suggests that T-lymphocyte mRNA measurements may be a sensitive index of zinc status in humans.

This thesis describes two main sections of work, an examination of a commercial product, Intrasite Gel, and the development of an algorithm for variable selection using projected latent structures.Following on from the successful development of a variable selection procedure for multivariate linear regression this work looks at transferring this idea for use with projected latent structures. The first part of this thesis will show how the variable selection algorithm was developed and used with three different data sets. The algorithm will be shown to be superior to standard projected latent structures, for linear multi-component data. Although the final algorithm developed requires considerable computing resources to carry out this is compensated for by significantly improved model predictions and robustness. The final algorithm developed is written to run using MATLAB on any computer platform that supports this application, though the principles of operation could be transferred to another method of execution, for example custom code written in C or Pascal. The approach used in the development of this method is that the ability of the model to predict unknownsamples is of far greater importance than the internal performance of the model. All the assessments of the procedures developed are based on the ability of the model to predict accurately and precisely samples that were not presented to the model during the training stage.The second section of this thesis is concerned with the study of Intrasite Gel, produced by Smith & Nephew Ltd. Hull. The material in question is a medical device intended to assist in the treatment and healing of wounds that are necrotic, sloughy or granulating. The product is characterised by its ability to maintain moisture equilibrium in a wound environment and to provide a suitable medium to encourage the growth of new cell tissue. Medical devices require registration, and as part of that registration a number of tests are made on samples to ensure that the material meets the required specifications. There was some concern at Smith & Nephew that the tests they were required to carry out as part of the device registration were not providing appropriate information about the product. Of particular interest was the fluid absorption property as it was suspected that the test has a large amount of random error associated with it and an investigation was required to examine this test and to provide an alternative procedure should the fluid absorption test prove inadequate. Also of interest to Smith & Nephew was the issue of sampling frequency, as it was felt that this should also be examined to determine whether the correct rate of sampling to ensure product quality was being carried out. The work reported here shows that the fluid absorption test as it stands is insufficient to the task of monitoring this property of Intrasite gel and that an alternative test should be considered. This work also showed that current sampling rate was too high and that the high sampling rate may in fact cause misleading assumptions as to the stability and quality of the product.

Thesis (M. Phil.)--University of Hong Kong, 2008. / Also available in print.

Thesis (Ph. D.)--Northeastern University, 2008. / Title from title page (viewed March 9, 2009). Graduate School of Arts and Sciences, Dept. of Chemistry and Chemical Biology. Includes bibliographical references (p. 255-279).

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 127-146) Also available in print.

Thesis (Ph. D.)--Ohio State University, 2008.

Tesis de grado Presentada a la carrera de Ingenieria Zootecnica, Universidad Catolica Boliviana "San Pablo" Unidad Academica Campesina Tiahuanaco, Carrera Ingeniera Zootechnica. / Abstract in Spanish and English.

Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Chemical and Biochemical Engineering." Includes bibliographical references (p. 94-99).

Thesis (Ph. D.)--Colorado State University, 2004. / Includes bibliographical references.