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Dietary zinc deficiency was induced in four healthy male volunteers. The diet used was high in phytate (phytate:zinc molar ratio 381) and the depletion period was preceded by a 3 day starvation period. In the depletion period, there was a significant decrease in plasma zinc and urinary zinc excretion. The subjects also adapted to the low zinc intake by decreasing the faecal excretion of zinc. One subject (No.2) developed clinical signs of zinc deficiency and also had the lowest plasma zinc concentration at the end of the depletion stage. Whole body protein turnover was assessed by an 8hr primed constant infusion of Li-[1-¹³C]leucine. Zinc deficiency had an effect on whole body protein turnover in only one subject (No. 2). In this subject, there was a decrease in leucine oxidation (71%), protein synthesis (31%) and degradation (39%). In this group as a whole, zinc depletion was associated with a significant decrease in urinary excretion of 3-methylhistidine. Zinc deficiency appeared to have no effect on substrate utilization. With regard to zinc kinetics, zinc deficiency was associated with a significant decrease in the size of the plasma zinc pool and a liver pool. There was also a decrease in the flux between these two zinc pools, and an increase in the fractional decay of zinc from the plasma pool to the liver pool. Two further studies were carried out. In 4 volunteers the effect of a 3 day starvation period on whole body protein turnover and zinc kinetics was investigated. There was a significant increase in leucine oxidation and in the size of a liver zinc pool. In 6 volunteers, the effect of phytate on zinc kinetics was investigated. The addition of phytate to the test meal, (phytate:zinc molar ratio 88) was associated with a decrease in the size of a liver zinc pool.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. Includes: Effects of zinc deficiency in the diets of hens / E.W. Kienholz, D.E. Turk, M.L. Sunde and W.G. Hoekstra. Reprinted from Journal of nutrition, vol. 75, no. 2 (Oct. 1961), p. 211-221. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 90-93).

The response of field corn to iron and zinc fertilization was studied using a split plot experimental design in Millard County, Utah, in cooperation with the Utah Stat e University Extension Agent and a local farmer. ~!ainp l ot treatment applications consisted, on an acre basis, of (1) 5 t ons of sulfuric acid, (2) 1 ton sulfuric acid, (3) 1.8 tons gypsum, (4) check plot. Subplot treatments were (1) Fe at 5 lbs/Ac, (2) Zn at 10 lbs/Ac, (3) Fe and Zn at 5 and 10 lb / Ac, respectively, (4) check plot . The iron and zinc applications were essentially rendered unavailable by reactions of the applied iron and zinc with the highly calcareous soil matrix. Experimental variability and the relatively low rates of applied micronutrients combined to produce insignificant yield responses to micronutrient fertilization. Another study was conducted to predict the soil iron critical level. Five soils from Millard County, representing some of the soils low in iron and zinc,were selected for a greenhouse study. All five of the soils were equal l y divided into three groups and assigned one of three pretreatments. One- third of the soils were stressed by successive croppings with corn and oats. One-third of the soils were fertilized with Fe chelate and znso 4 at 5 ppm each as a pretreatment. And one-third of the soils did not receive a pretreatment. The pretreatments were designed to obtain a broader range of soil iron concentrations. After the pre treatments were completed on all of the soils, a randomized block experimental design was employed to measure potential yield increases in corn produced by the addition of Fe chelate . Two corn genotypes, an iron-efficient corn inbred (WF9) and an iron efficient corn mutant (Ysl/Ysl), were utilized in the gr eenhouse study. The treatments were (1) 5 ppm Fe chelate plus corn inbred WF9, (2) 5 ppm Fe chelate plus corn mutant Ysl/Ysl, (3) no Fe addition plus corn inbred WF9 , (4) no Fe addition plus corn mutant Ysl/Ysl. Significant yield responses to Fe fertilization were determined by an LSD statistical test . Generally, soils with a DTPA extractable iron level greater than 5 ppm did not respond to applied iron. Similar yield responses were obtained for the iron-efficient and ironinefficient varieties. A tentative critical level of DTPA extractable iron of 5 ppm was proposed for the calcareous soils of Millard County, Utah.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Cathy W. Levenson, Florida State University, College of Human Sciences, Dept. of Nutrition, Food, and Exercise Sciences. Title and description from dissertation home page (viewed May 18, 2004). Includes bibliographical references.

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.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 55-63). Also available via the Internet.

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1970. / Also available via the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Last two leaves of Table of Contents misnumbered v, vi instead of x, xi. Typescript. Vita. Includes bibliographical references. Also available on the Internet.