Two-week low iodine diet is necessary for adequate outpatient preparation for radioiodine rhTSH scanning in patients taking levothyroxine

We evaluated a self-managed, outpatient, low iodine diet (LID) (<50 microg/day) designed to decrease total body iodine (TBI) in preparation for radioiodine (131I) scans. However, levothyroxine (LT4) ingestion is a significant source of dietary iodine in recombinant human TSH (rhTSH)-stimulated studies. Measuring urine iodine to creatinine ratios (I/Cr), a reflection of TBI, we evaluated the LID for 7-day and 14-day periods to determine the efficacy of our LID to deplete TBI, with and without LT4. Patients following the LID for 14 days (n = 28) without LT4 attained the goal of an iodine deficient state (I/Cr <50 microg/g) in 78% of cases, establishing the diet's efficacy in significantly reducing TBI. In patients taking LT4, 7 days of the LID was insufficient to attain this goal of true iodine deficiency. However, a 14 day LID while taking LT4 resulted in 21% of patients being iodine deficient. For diagnostic purposes, a 7 day LID period (n = 21) suboptimally but adequately (I/Cr <100 microg/g) prepared 41% of the patients, whereas 14 days on the diet (n = 24) adequately prepared 71% of the patients taking LT4. Our simple, self-managed, outpatient, LID effectively makes patients iodine deficient. Though less efficacious when taking LT4, this LID adequately reduces TBI for rhTSH-stimulated 131I uptake scans when followed for 14 days.

Trace element biology: the knowledge base and its application for the nutrition of individuals and populations

Impressive strides are being made in the understanding of trace element metabolism and function. This is underscored by the many contributions in these proceedings. However, not so impressive are: i) the precise recognition of mild trace element deficiencies and how to establish their functional consequences, possibly confounded by concurrent trace element inadequacies, are difficult to assess, ii) approaches to the quantitative determination of requirements for trace elements remain unsatisfactory and archaic, in so many ways, iii) our understanding of the extent of the biological basis for the variation in requirements among apparently similar individuals is poor, and iv) much needs to be learned about the quantitative extent to which genetic, epigenetic and dietary factors interact to determine the nutritional phenotype. Some ideas are presented as to how we might embrace, in the context of a reconstructive approach, the exciting new knowledge and related techniques emerging during the postgenome era and develop new paradigms for assessing trace element needs and status, and for establishing effective nutrient intake under different conditions of complex genotype-environment interactions. Metabolites are functional cellular entities and I also urge a vigorous application of metabolomics and of metabolic profiling that is closely linked with genomics, proteomics, trace element kinetics and system analysis, as components of the new integrative paradigm. We need to understand the system and its strategy, not only the molecular details of its component parts and its individual controls. An interdisciplinary research and teaching enterprise will be necessary to best achieve this aim. All of this is related to our common goal to promote, through expanded biological knowledge and its effective application, the enhanced role of trace elements for human well-being.

Paradoxical effects of chemicals in the diet on health

In 1992, Block et al. published a summary of 200 epidemiological investigations which indicated that a diet that was high in fruit and vegetables cut cancer risks approximately in half. These investigations used conventionally farmed produce that contained traces of synthetic pesticides and mycotoxins as well as an estimated 10,000 secondary products (i.e. natural pesticides). Dietary consumption of fruits and vegetables also reduces risks of cardiovascular disease, cataracts and brain dysfunction. Before genetic manipulation is undertaken to elevate or diminish any individual constituent of fruits and vegetables, the contribution of each of these constituents to health must be better understood, as in many cases their effects on health can be paradoxical.

Effects of protein deprivation on alpha1(I) and alpha1(III) collagen and its degrading system in rat skin

Protein malnutrition affects the status of dermal collagen, the major structural protein in the skin. However, the molecular mechanism underlying the alteration of collagen fibers in the skin by protein deficiency remains unknown. In the present study, the effect of dietary protein deprivation on collagen metabolism was studied by analyzing the status of the synthesis and degradation of collagen in the dorsal skin of rats. Feeding on a protein-free diet for 8 days caused a dramatic decrease in both types I and III tropocollagen with a concomitant decrease in their mRNA levels, with type III collagen being more severely affected. The active form of collagenase was significantly decreased by protein deprivation, whereas the latent form was not affected. The mRNA levels of collagenase and its inhibitors (TIMP-1 and 2) were also decreased by protein deprivation. These results suggest that both the synthesis and degradation of types I and III collagen were affected by protein deficiency.

Lifestyle, minerals and health

This paper proposes that most poor health and behavioral conditions are related to a deficiency of essential minerals or an excess of toxic ones. Clients requesting a hair mineral analysis were required to complete a questionnaire including lifestyle, health status and diet. Most prevalent health conditions in order of frequency were: depression, allergies, low back pain, arthritis, cardiovascular disease and poor digestion. Most deficient minerals were chromium, magnesium, zinc and calcium. Aluminum was the most frequent toxic mineral. it is proposed that such mineral abnormalities were caused by an over consumption of nutrient-poor, highly processed foods such as white flour, sugar and harmful fats. Such a diet promotes poor lifestyles such as smoking, drug abuse, alcoholism and criminal activity. Poor diets and dangerous lifestyles precedes the development of most prevalent diseases. The most common one is cardiovascular disease which increased at an alarming rate in the last century.

Neonatal skin care: the scientific basis for practice

OBJECTIVE

To review the literature addressing the care of neonatal skin.

DATA SOURCES

Computerized searches in MEDLINE and CINAHL, as well as references cited in articles reviewed. Key concepts in the searches included neonatal skin differences; neonatal skin and care practices for skin integrity; neonatal skin and toxicity; permeability; and contact irritant sensitization.

STUDY SELECTION

Articles and comprehensive works relevant to key concepts and published after 1963, with an emphasis on new findings from 1993 to 1999. One hundred two citations were identified as useful to this review.

DATA EXTRACTION

Data were extracted and organized under the following headings: anatomy and physiology of the skin; physiologic and anatomic differences in neonatal skin; nutritional deficiencies; skin care practices; and care of skin breakdown.

DATA SYNTHESIS

Newborns' skin is at risk for disruption of normal barrier function because of trauma. In light of available evidence about differences in neonatal skin development, clinical practice guidelines are suggested for baths, lubrication, antimicrobial skin disinfection, and adhesive removal. In addition, basic care practices are suggested for maintaining skin integrity, reducing exposure to potentially toxic substances, and promoting skin health beyond the neonatal period. Preventive care recommendations are made for reducing trauma, protecting the skin's immature barrier function, and promoting skin integrity.

CONCLUSIONS

This review generated evidence with which to create a new and comprehensive practice guideline for clinicians. Evaluation of the guideline is under way at 58 U.S. sites.

Lysine deficiency and host resistance to anthrax

1. Lysine deficiency has been produced in rats by placing the weanling animals on an experimental diet in which gluten replaced the casein of the control diet. Both diets were complete in all other known requirements. 2. The resistance of the deficient animals to a subcutaneous challenge of several concentrations of B. anthracis spores, was decreased. Deaths occurred within 2 days post inoculation. 3. When lysine was added to the gluten diet to bring the total concentration to that of the control diet, the growth rate of the animals was maintained but a decrease in resistance remained, although not as great as on the gluten diet. 4. Changes in the tissues associated with lysine deficiency are reported. 5. It is not unreasonable to state that within the time frame of our experiments, the decreased ability of the RES of the host to clear the invading organism from the tissues and subsequently to break down the organism is a major factor of the decreased resistance of the lysine-deficient rats to anthrax.

Inulin and thiocyanate spaces of rat in starvation and undernutrition

Inulin space and thiocyanate space determinations were made on three groups of male rats: the first group was chronically undernourished by feeding a restricted ration for 10 weeks, the second group was starved with free access to water, and the third was made up of normal male controls. The inulin space was found to expand relative to the final body weight or lean body mass in the undernourished animal. No absolute increase in inulin space took place. In starvation the inulin space did not change in proportion to the body weight and its absolute value decreased. The thiocyanate space relative to the final body weight or lean body mass expanded slightly but significantly in chronic undernutrition and in starvation, but no absolute increase of the thiocyanate space took place.

Lack of a recommended dietary allowance for copper may be hazardous to your health

The 10th edition of Recommended Dietary Allowances (RDA) did not include an RDA for copper; rather a safe and adequate daily intake was suggested. Criteria, history and uses of RDAs were summarized along with data on dietary intakes, balance and depletion experiments, low (fats and oils, skim milk and yogurt) and high (legumes, mushrooms, nuts and seeds) copper foods and hazards of zinc supplements. Bone disease and cardiovascular disease from diets-low in copper have been studied in animals for decades. Men and women fed diets close to 1 mg of copper per day, amounts quite frequent in the US, responded similarly to deficient animals with reversible, potentially harmful changes in blood pressure control, cholesterol and glucose metabolism, and electrocardiograms. Women supplemented with trace elements including copper experienced beneficial effects on bone density. These data exceed similar data on magnesium, selenium and zinc and are sufficient for establishing an RDA. Ischemic heart disease and osteoporosis are likely consequences of diets low in copper. Numerous anatomical, chemical and physiological similarities between animals deficient in copper and people with ischemic heart disease have been noticed. Association between osteoporosis and low copper status deserves further inquiry. Augmenting low copper diets with high copper foods may be beneficial. Committees that establish RDAs should return to the traditions of the first nine editions and make recommendations that promote health and nutritional welfare, meet functional needs, prevent disease and promote public welfare.

STUDIES ON ESSENTIAL FATTY ACID DEFICIENCY. EFFECT OF THE DEFICIENCY ON THE LIPIDS IN LIVER MITOCHONDRIA AND OXIDATIVE PHOSPHORYLATION

1. Dietary deficiency of essential fatty acids results in a twofold increase in the neutral lipid content of liver mitochondria as compared with the corresponding value for stock-fed rats. 2. Deficiency produces changes in the pattern of the constituent fatty acids of the main phospholipid fractions of liver mitochondria which are similar to those previously reported for the lipids of whole liver. There is a fall in the content of C(18:2) acid and to a smaller extent of C(20:4) acid associated with a rise of C(16:1), C(18:1) and C(20:3) acids. 3. Deficiency results in small decreases in the phosphorylation quotients of liver mitochondria during oxidation of succinate and pyruvate, but the values lie within the range reported for normal mitochondria. Mitochondrial respiration with succinate is decreased as a result of deficiency but no change was observed with pyruvate as substrate.

STRUCTURAL CHANGES IN ISOLATED LIVER MITOCHONDRIA OF RATS DURING ESSENTIAL FATTY ACID DEFICIENCY

Liver mitochondria isolated in 0.44 M sucrose from rats deficient in essential fatty acids (EFA) oxidized citrate, succinate, alpha-ketoglutarate, glutamate, and pyruvate at a faster rate than did mitochondria isolated from normal rats; however, the oxidation of malate, caprylate, and beta-hydroxybutyrate was not significantly increased. The mitochondria from deficient rats exhibited an increased ATPase activity and extensive structural damage as revealed by electron microscope examination of thin sections. An increase in citrate oxidation and ATPase activity, together with some structural damage, could be demonstrated as early as the 4(th) week in rats on a fat-free diet. Saturated fat in the diet did not prevent the change in mitochondrial structure but accelerated its appearance. Both the biochemical and structural defects could be reversed within three weeks after feeding deficient rats a source of EFA. In the presence of a phosphate acceptor the effect of EFA deficiency on substrate oxidation was largely eliminated. A trend toward a reduced efficiency of oxidative phosphorylation was noted in mitochondria from EFA-deficient rats, but significant uncoupling was found only in the case of citrate, beta-hydroxybutyrate, and glutamate in the presence of malonate. Together with the increased ATPase activity, the uncoupling of phosphorylation could account for the poor respiratory control found with the deficient preparation. However, EFA deficiency was without effect on the respiration of liver slices, which supports the belief that the observed changes in oxidation and phosphorylation are an artifact resulting from damage sustained by the deficient mitochondria during their isolation.