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The metabolism of ethanol to acetaldehyde has been visualized in living lung epithelial cells using a hydrazinyl naphthalimide fluorescent probe. Utilizing a condensation reaction between carbonyls and a hydrazine moeity, we demonstrate that the fluorescent probe (Aldehydefluor-1) AF1 reacts with a range of reactive carbonyl species including formaldehyde, acetaldehyde, glyoxylic acid, and methyl glyoxal. With AF1, it is possible to directly visualize endogenous carbonyl metabolites. Here, we have applied it towards the visualization of acetaldehyde generated from alcohol dehydrogenase mediated ethanol metabolism, validating it as a useful tool to study the roles of alcohol in respiratory disease and other pathological mechanisms.

Heat stress results in a multitude of biological and physiological responses which can become lethal if not properly managed. It has been shown that heat stress causes significant adverse effects in both human and animals. Different approaches have been proposed to mitigate the adverse effects caused by heat stress, among which are special diet and probiotics. We characterized the effect of the yeast fermentate EpiCor (EH) on the prevention of heat stress-related complications in rats. We found that increasing the body temperature of animals from 37.1±0.2 to 40.6±0.2°C by exposure to heat (45°C for 25min) resulted in significant morphological changes in the intestine. Villi height and total mucosal thickness decreased in heat-stressed rats pre-treated with PBS in comparison with control animals not exposed to the heat. Oral treatment of rats with EH before heat stress prevented the traumatic effects of heat on the intestine. Changes in intestinal morphology of heat-stressed rats, pre-treated with PBS resulted in significant elevation of lipopolysaccharides (LPS) level in the serum of these animals. Pre-treatment with EH was effective in the prevention of LPS release into the bloodstream of heat-stressed rats. Our study revealed that elevation of body temperature also resulted in a significant increase of the concentration of vesicles released by erythrocytes in rats, pre-treated with PBS. This is an indication of a pathological impact of heat on the erythrocyte structure. Treatment of rats with EH completely protected their erythrocytes from this heat-induced pathology. Finally, exposure to heat stress conditions resulted in a significant increase of white blood cells in rats. In the group of animals pre-treated with EH before heat stress, the white blood cell count remained the same as in non-heated controls. These results showed the protective effect of the EH product in the prevention of complications, caused by heat stress.

EpiCor, derived from Saccharomyces cerevisiae, has been shown to have immunomodulating properties in human clinical trials and in vitro. However, the underlying mechanisms behind its immune protection via the gut remain largely unknown. Therefore, the aim of this study was to use an integrated in vitro approach to evaluate the metabolism of EpiCor by the intestinal microflora, its modulating effect on the gut microbiota, and its anti-inflammatory activity on human-derived cell lines. Using the SHIME model, in combination with a mucus adhesion assay, has shown that low doses of EpiCor have a prebiotic-like modulatory effect on the luminal- and mucosa-associated microbiota. These include gradual changes in general community structure, reduction of potential pathogens, quantitative increase in lactobacilli, and qualitative modulation of bifidobacteria. Moreover, by combination of the SHIME with Caco-2 cells and Caco-2/THP1 cocultures, a significant decrease in pro-inflammatory cytokines was observed at the end of the treatment period.

Soil erosion due to annual cropping on highly erodible farmland is a major ecological concern in the wheat growing regions of Washington State. In response to requests from farmers, the winter wheat breeding program at Washington State University has been developing perennial wheat selected from crosses between wild wheatgrass species and commonly grown annual wheat cultivars. In 2005/06, we conducted field trials of the most promising perennial wheat breeding lines derived from interspecific crosses between tall wheatgrass (Thinopyrum elongatum) and bread wheat (Triticum aestivum). Thirty-one perennial breeding lines and two annual winter wheat cultivars were evaluated for nutritional value in the form of grain mineral concentration, multiple baking and milling quality traits, and ease of grain threshability. The objective of this study was to identify the strengths and weaknesses of these post-harvest traits in the perennial wheat lines derived from these interspecific crosses. Mineral nutrient concentrations in the perennial lines were 44, 40, 24, 23, 32, 30 and 33% higher than the annual control cultivars for calcium, copper, iron, magnesium, manganese, phosphorus and zinc, respectively. The annual cultivars had a higher grain mineral content per unit area of land than the perennial lines, due primarily to the higher grain yields of the annual cultivars. Compared to the annual wheat cultivars, the perennial lines produced grain with smaller seed size, lower test weight and reduced flour yield, mix time and loaf volume. Protein content was 3.5–4.5% higher in the perennial lines than in the annual cultivars. The threshability index (TI) ranged from 0.63 to 0.89 in the perennials (μ=0.75); significantly lower than the mean TI of the annual cultivars (μ=0.97). The significant genotype×location interaction found for TI suggests that the variation in annual precipitation positively influenced some perennial lines to express greater threshability. In addition to transferring traits important to the perennial growth habit in wheat, the wild wheatgrass species also introduced beneficial characteristics (i.e. increased protein and mineral concentration) and deleterious traits (poor threshing grain and inferior baking qualities). This research gives researchers a platform from which to direct further research and selection in the development of perennial wheat.

This double-blind, randomized, placebo-controlled pilot study was designed to evaluate effects of consumption of an antioxidant-rich, yeast culture-based high-metabolite immunogen EpiCor ® . Twenty-five healthy participants con- sumed 0.5 gram EpiCor ® or placebo daily for 5 weeks. The hematocrit increased significantly in the EpiCor ® group (p

The diet of approximately three billion people worldwide is nutrient deficient and most of the world’s poorest people are dependent on staple food crops as their primary source of micronutrients. One component of the solution to nutrient deficiencies is collaboration among plant breeders, cereal chemists and nutritionists to produce staple crop cultivars with increased mineral nutrient concentration. Sixty-three historical and modern wheat cultivars were evaluated for grain yield and concentration of calcium, copper, iron, magnesium, manganese, phosphorus, selenium, and zinc. While grain yield has increased over time, the concentrations of all minerals except calcium have decreased. Thus a greater consumption of whole wheat bread from modern cultivars is required to achieve the same percentage of recommended dietary allowance levels contributed by most of the older cultivars. The decrease in mineral concentration over the past 120 years occurs primarily in the soft white wheat market class, whereas in the hard red market class it has remained largely constant over time. This suggests that plant breeders, through intentional selection of low ash content in soft white wheat cultivars, have contributed to the decreased mineral nutrient concentration in modern wheat cultivars. These results contradict the theory that there exists a genetically based, biological trade-off between yield and mineral concentrations. Therefore, using the abundant variation present in wheat cultivars, it should be possible to improve mineral concentrations in modern cultivars without negatively affecting yield.

Beans improve serum lipids and may reduce the risk of colon cancer by increasing colonic SCFA formation. We assessed whether pinto bean consumption affects in vitro fecal bacterial fermentation and production of SCFA, colonic bacterial populations, and serum lipids. Adults grouped as premetabolic syndrome (pre-MetSyn) (n = 40) or controls (n = 40) were randomly assigned to consume either a bean entree [1/2 cup (130 g) of dried, cooked pinto beans] or an isocaloric chicken soup entree daily for 12 wk. Measurements included in vitro fecal fermentation of various resistant starch substrates, fecal bacterial speciation, and blood lipids. When expressed as a difference between baseline and treatment, propionate production from fecal material fermented in vitro with bean flour was higher (P < 0.02) in volunteers consuming beans than in those consuming soup. During the treatment period alone, bean consumption did not affect propionic acid production with any substrate but lowered (P < 0.02) butyric acid production when cornstarch was the substrate. In all volunteers, bean consumption decreased fecal production of isovaleric (P < 0.05) and isobutyric (P < 0.002) acids from cornstarch by as much as 50%. Of the bacterial populations tested, only Eubacterium limosum was affected by bean consumption and was approximately 50% lower than in those consuming soup. Beans lowered serum total cholesterol (P < 0.014) by approximately 8% in the controls and 4% in the pre-MetSyn group. Bean consumption lowered serum HDL-cholesterol (P < 0.05) and LDL-cholesterol (P < 0.05) in both groups without affecting serum triglycerides, VLDL cholesterol, or glucose. This study provides evidence that bean consumption can improve lipid profiles associated with cardiovascular disease, but does not clearly confer health benefits related to colon cancer risk.

The purpose of this study was to determine the effects of copper deficiency on key aspects of homocysteine metabolism that involve methionine recycling and transsulfuration. Male weanling Sprague-Dawley rats were fed AIN-93G-based diets containing

The goal of this study was to determine the effects of Fe supplementation on the anemia of Cu deficiency in rats. In addition, we observed changes in serum and organ Cu and Fe during the development of Cu deficiency. In Experiment 1, weanling male Sprague-Dawley rats were fed AIN-93G diets containing either0.3 mg Cu [Cu deficient (CuD)] or 6.0 mg Cu [Cu adequate (CuA)] per kilogram diet, and 35 mg Fe/kg. Five rats from each group were killed at intervals for the analysis of hematologic parameters and mineral content of various organs. In Experiment 2, two groups of 24 rats each were fed either the CuA diet or the CuD diet for 14 days. Then, three sets of eight rats in each group received three separate Fe treatments: (1) daily intraperitoneal injections of 400 mug Fe (Cu-free ferric citrate) per rat for another 14 days, (2) fed similar diets that contained three times the normal amount of Fe (105 mg/kg) for 14 days, or (3) received no further Fe treatment. At day 21, all rats were fed a 1-g meal labeled with (59)Fe to determine Fe absorption. After 28 days, rats were killed for the analyses of Fe and Cu status. Results of Experiment 1 showed that within 14 days, CuD rats had lower blood hemoglobin (Hgb), red blood cell count, and mean corpuscular volume than CuA rats. Copper concentrations in all tissues measured were lower in the CuD rats than in controls. Serum ceruloplasmin (Cp) activity in CuD rats was only 0.8% of CuA rats at day 7. During this period, enterocyte and liver Fe concentrations were elevated and serum Fe was reduced, but there was no change in spleen Fe. Results of Experiment 2 showed that CuD rats absorbed less Fe than CuA rats. Supplemental Fe by diet or by intraperitoneal injections did not prevent anemia in the CuD rats or affect other parameters of Cu status. Serum total iron binding capacity [transferrin (Tf)] was not changed by Cu deficiency or by Fe supplementation; however, percent Tf saturation was reduced in CuD rats but was not enhanced by Fe supplementation. These data suggest that anemia of Cu deficiency occurs because of reduced Fe absorption, and it inhibits release of Fe from the liver and inefficient loading of Fe into Tf because of very low plasma Cp activity. The latter then leads to inefficient delivery of Fe to the erythroid cells for heme and Hgb synthesis.

Selenium (Se) is an essential nutrient for humans and animals. The Se RDA for adult humans is 55 mug/d; however, dietary amounts as high as 200 mug/d in the highly available form of selenomethionine in yeast were shown to reduce the incidence of certain cancers. A number of natural foods contain relatively high amounts of Se; for the most part, however, the availability of food Se for absorption and utilization is unknown. This experiment was conducted to determine the bioavailability of Se from a high-protein, high-fiber bran-isolate of buckwheat groats that contains Se. The method used was based on the ability of Se from buckwheat bran to restore Se-dependent enzyme activities and tissue Se concentrations in Se-deficient rats. The responses produced from buckwheat bran Se were compared with a standard response curve generated by feeding graded amounts of Se as sodium selenite (Na(2)SeO(3); Na selenite) or selenomethionine (SeMet) in a newly reformulated AIN-93G-Torula yeast diet with a more balanced nutrient composition than older diets of this nature. Relative bioavailability was determined by using the slope-ratio assay method for enzyme data, or the parallel lines assay method for tissue Se concentration data. Results showed that Se availability from buckwheat bran based on the restoration of plasma Se was 70-80% as high as Na selenite or SeMet. However, when based on the restoration of muscle Se, buckwheat bran was 90% as high as Na selenite, but only 60% as high as SeMet. When using the ability of dietary Se to restore whole blood and liver glutathione peroxidase activity, buckwheat bran Se was 75-80% as high as Na selenite or SeMet. However, for the restoration of liver thioredoxin reductase, buckwheat bran Se was only 40% as high as Na selenite and 70% as high as SeMet. The relative bioavailability of Se from buckwheat bran with all variables considered was approximately 73% whether measured against Na selenite or SeMet. Although some variables indicated low bioavailability of Se from buckwheat bran, other factors such as Se speciation in the bran, digestibility of the bran, the cooking process, and combinations with other foods in the diet should be considered and analyzed before firm conclusions can be reached.

Thermally induced conformational transitions of three proteins of increasing intrinsic disorder-cytochrome c, the tumor suppressor protein p53 DNA binding domain (p53 DBD), and the N-terminus of the oncoprotein murine double minute 2 (NT-MDM2)-have been studied by native mass spectrometry and variable-temperature drift time ion mobility mass spectrometry (VT-DT-IM-MS). Ion mobility measurements were carried out at temperatures ranging from 200 to 571 K. Multiple conformations are observable over several charge states for all three monomeric proteins, and for cytochrome c, dimers of significant intensity are also observed. Cytochrome c [M + 5H](5+) ions present in one conformer of CCS ∼1200 Å(2), undergoing compaction in line with the reported Tmelt = 360.15 K before slight unfolding at 571 K. The more extended [M + 7H](7+) cytochrome c monomer presents as two conformers undergoing similar compaction and structural rearrangements, prior to thermally induced unfolding. The [D + 11H](11+) dimer presents as two conformers, which undergo slight structural compaction or annealing before dissociation. p53 DBD follows a trend of structural collapse before an increase in the observed collision cross section (CCS), akin to that observed for cytochrome c but proceeding more smoothly. At 300 K, the monomeric charge states present in two conformational families, which compact to one conformer of CCS ∼1750 Å(2) at 365 K, in line with the low solution Tmelt = 315-317 K. The protein then extends to produce either a broad unresolved CCS distribution or, for z9, two conformers. NT-MDM2 exhibits a greater number of structural rearrangements, displaying charge-state-dependent unfolding pathways. DT-IM-MS experiments at 200 K resolve multiple conformers. Low charge state species of NT-MDM2 present as a single compact conformational family centered on CCS ∼1250 Å(2) at 300 K. This undergoes conformational tightening in line with the solution Tmelt = 348 K before unfolding at the highest temperatures. The more extended charge states present in two or more conformers at room temperature, undergoing thermally induced unfolding before significant structural collapse or annealing at high temperatures. Variable-temperature IM-MS is here shown to be an exciting approach to discern protein unfolding pathways for conformationally diverse proteins.

The association between the prevalence of antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8 [HHV-8]) and sociodemographic, sexual, reproductive and lifestyle factors was investigated in a study of adults presenting with cancer at hospitals in Kampala, Uganda. Patients were interviewed and tested for antibodies against KSHV (using an indirect immunofluorescent assay). Data are presented for 607 patients who were not infected with the human immunodeficiency virus-1 (HIV) and who did not have Kaposi's sarcoma (these included people with cancers of the uterine cervix [140], breast [58], liver [41], oesophagus [36], lymphoma [47], other cancers [285] and benign tumours [63]). The prevalence of anti-KSHV antibodies was 50% overall (302/607) and did not differ significantly by cancer site (p = 0.4) or sex (p = 0.2), but increased linearly with age from 35% in those under 25 years to 55% in those 45 years and over (chi(2) trend [1 df] = 9.1; p < 0.001). After adjusting for age and sex, anti-KSHV antibodies were more common in tribal groups other than the Baganda tribe (54% vs. 45% among Baganda; p = 0.02), but there was no significant (p > 0.05) variation in seroprevalence by district of birth, region of residence prior to becoming ill or various measures of wealth. The prevalence of anti-KSHV antibodies decreased with increasing number of older siblings, although this may be due to chance (p = 0.05) and was higher among people who had ever been married (p = 0.03). There was no significant association (p > 0.05) between the presence of antibodies against KSHV and other sexual and reproductive factors. Among the 302 patients with anti-KSHV antibodies, the proportion with high titres increased linearly with increasing age (p = 0.03) and was higher among those reporting having had a blood transfusion (p = 0.03). In conclusion, in this population in Uganda, where KSHV is relatively common, the prevalence of anti-KSHV antibodies increased with age but showed little association with nearly 50 other factors studied.

As part of a larger investigation of cancer in Uganda, we conducted a case-control study of Kaposi's sarcoma in human immunodeficiency virus-1 (HIV)-seronegative adults presenting at hospitals in Kampala. Cases comprised 117 HIV-seronegative patients with Kaposi's sarcoma and controls comprised 1,282 HIV-seronegative patients with a provisional diagnosis of cancer other than Kaposi's sarcoma. Study participants were interviewed about social and lifestyle factors, tested for HIV and, if there was sufficient sera, for antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8 [HHV8]), using an immunofluorescent assay. Independent effects of these factors were identified using unconditional logistic regression, after adjusting for age group (

Survival, growth and dietary intake (DI) variables were monitored in a chronic 114-wk study in which male Sprague-Dawley rats [n = 120; National Center for Toxicological Research (NCTR) colony] consumed the AIN-93M purified diet ad libitum (AL), or an amount reduced by 31% of total AL intake inclusive of all macro- and micronutrients. The main objectives were to ascertain the survival characteristics of rats fed the AIN-93M diet and to determine whether dietary restriction (DR) increases longevity of rats fed this casein-based diet compared with the use of mixed-protein sources of the NIH-31 cereal-based diet in an earlier study. Body, liver, brain, the brain/body ratio, spleen, thymus and kidney weights, body length and body density were decreased (P < 0.05) by DR, whereas testis weight and skull length were not altered by DR. Significant age effects at 58 and 114 wk were found for body, brain, the brain/body ratio, liver and testis weights, and body density. Survival rates for the AL and 31% DR groups were 43.3 and 57.5%, respectively. Survival curves were not significantly different. The survival rate for AL rats fed the AIN-93M diet was not different from that of AL rats fed the NIH-31 diet (43.3 and 51.7%, respectively). However, the survival rate for 31% DR rats fed the AIN-93M diet was significantly lower than 25% DR rats fed the NIH-31 diet (57.5 and 87.5%, respectively) although both groups had similar body weights and energy intake at various ages. Nutritional components in the NIH-31 diet that are missing and/or reduced in the AIN-93M diet may interact with DR to increase 114-wk survival. Although the survivability, growth and anatomical results of this study suggest that the AIN-93M diet is suitable for chronic rodent studies, additional studies such as comprehensive histopathologic and physiologic investigations must be undertaken to complete the evaluation process.

The aim of this study was to document anti-inflammatory properties of a dried fermentate derived from Saccharomyces cerevisiae (EpiCor(®)), hereafter referred to as dried fermentate in vitro using cell-based bioassays, and in vivo using a skin irritation model in healthy humans. In vitro testing involved parallel assessment of primary human polymorphonuclear (PMN) cell formation of reactive oxygen species (ROS) and migration toward the inflammatory mediator Leukotriene B4. In vivo evaluation used a single-blind placebo-controlled design, where dermal histamine-induced inflammation was used as a model for the complex intercellular signals involved in the initiation, escalation, and resolution of the inflammatory response. Microvascular blood perfusion was evaluated using noninvasive laser Doppler probes applied to the inner forearms of 12 healthy human subjects, where parallel sites were treated with either dried fermentate or saline (placebo). Subjective scores of dermal irritation were also collected. Treatment of PMN cells in vitro resulted in reduced ROS formation and migratory activity toward Leukotriene B4. Clinical results demonstrated significantly reduced microvascular inflammatory responses to histamine-induced skin inflammation, and significantly reduced subjective scores of irritation at the inflamed sites treated with dried fermentate compared with the sites treated with placebo (P

The intake of food cadmium (Cd) in microg/day over time can increase the body burden of this element. Some human populations that consume subsistence rice-based diets low in calcium (Ca), iron (Fe), and zinc (Zn) are more susceptible to Cd poisoning than populations that consume more nutritious diets. This study determined the effects of marginal deficiencies of these essential elements on the absorption and organ retention of Cd from a natural food that contains Cd, edible sunflower kernels (Helianthus annuus L.; SFK). Weanling female rats were fed diets containing 20% SFK in a 2x2x2 factorial design with marginal and adequate amounts of Ca, Zn, and Fe. Marginal Zn (11 mg/kg) and Fe (13 mg/kg), and Cd (0.18 mg/kg) were derived solely from 20% SFK. These amounts of Fe and Zn represented 39 and 90% of the NRC requirement for the rat, respectively. The marginal dietary Ca concentration (2.5 g/kg) was one-half the NRC requirement. After 5 weeks on the experiment, rats were fed 1 g of their respective diets containing SFK extrinsically labeled with 37 kBq 109Cd, and absorption was determined by whole-body counting techniques. Rats were then killed and organs collected for 109Cd assays. No effect of treatment on weight gain was observed; however, when dietary Zn was low, feeding marginal Ca elevated Cd absorption by 50% (P0.05) over those fed adequate Ca and Zn. Feeding marginal Fe elevated Cd absorption2.5-fold (P0.001) over those fed adequate Fe. In contrast, the naturally occurring Zn in SFK that provided 90% of the rat's requirement was enough to deter excessive absorption of Cd and enough to alone prevent significant elevation of organ Cd. Organ content of 109Cd and Cd followed the same general pattern as whole-body absorption. These data show that marginal nutritional deficiencies of Ca and Fe can readily enhance the body burden of Cd that comes from the diet. Also, some natural competitors of Cd, such as Zn, contained in foods can independently minimize Cd absorption.

Copper (Cu) deficiency suppresses macrophage activities in animals and humans. Our previous studies indicated that the Induction of Cu deficiency in differentiated U937 monocytic cells impairs respiratory burst and bactericidal activities and lipopolysaccharide-mediated secretion of inflammatory mediators. The current investigation examined the roles of Cu in the monocytic differentiation process. Human U937 promonocytic cells were exposed to a high affinity Cu chelator (5 µM 2,3,2-tetraamine [tet]) for 24 hr before inducing differentiation by treatment with 1,25-dihydroxyvitamin D3 plus Interferon-γ (DI). This procedure decreased cell Cu by 55% without compromising cellular Zn, Fe, or general metabolic activities. Lower Cu status significantly attenuated the expression of maturation markers Mac-1 (CD11b), ICAM-1 (CD54), and LPS-R (CD14). This change was associated with a marked suppression in respiratory burst activity and killing of Salmonella. To examine if the adverse effect of inadequate Cu on the DI-induced differentiation represented a more general defect, U937 cells were treated with phorbol 12-myrlstate 13-acetate (PMA). Lower Cu status also suppressed PMA-mediated differentiation of U937 cells. Supplemental Cu, but not Zn or Fe, blocked the tet-induced declines in cell Cu, expression of maturation markers, and respiratory burst and bactericidal activities. These results demonstrate that Cu is essential for the monocytic differentiation process that contributes to the competency of the host's defense system.

Bovine pulmonary artery endothelial cells (BPAEC) were cultured in vitro under a variety of conditions to investigate how metallothionein (MT) might participate in zinc homeostasis. Experimental conditions included 10% serum to ensure that the in vitro environment would be a better reflection of the in vivo situation than with protein-free medium. MT was increased by acutely high zinc concentrations (100-200 micromol/L) in the extracellular environment. MT was relatively insensitive to moderate changes in zinc concentration (2-50 micromol/L), even after prolonged exposure for 7 to 12 days. BPAEC had reduced MT content when grown in medium containing serum that had been dialyzed to remove components with a molecular mass of less than 1,000, including zinc. Because the principal source of the major minerals in the experimental medium was not the serum, their concentrations in the final medium were not significantly influenced by serum dialysis. Restoring the zinc concentration in the medium containing the dialyzed serum did not restore MT content in BPAEC, suggesting that some small molecular weight molecule other than zinc established their basal MT content. This study did not identify these putative factors in serum, but hormones are likely candidates. Forty-eight-hour incubations of BPAEC with interleukin (IL-6) or dexamethasone increased cellular MT; however, 17beta-estradiol decreased MT, and IL-1 and adenosine 3',5'-cyclic phosphate (cAMP) had no discernible effect. We conclude that extracellular zinc concentrations have relatively little impact on the cellular concentrations of MT and zinc of BPAEC in vitro. Zinc homeostasis by BPAEC is not maintained by changing the MT concentration in response to changes in the extracellular zinc environment. (J. Nutr. Biochem. 10:00-00, 1999).

Sunflowers ( Helianthus annuus L. ) tend to remove cadmium (Cd) from the soil and deposit it in their seeds. The availability of Cd in sunflower kernels for absorption and deposition in animal tissues was studied using a 15-week feeding trial with both male and female rats begun at weanling age. Diets included (1) purified basal diet with no sunflower kernels (85 μg Cd/kg), (2) basal diet containing 20% ground low-Cd sunflower kernels (120 μg Cd/kg), (3) basal diet containing 20% ground high-Cd sunflower kernels (195 μg Cd/kg), and (4) basal diet containing 20% ground low-Cd sunflower kernels plus Cd chloride (175 μg Cd/kg). In a second experiment, adult rats were fed sunflower kernels that contained an endogenous or exogenous label of 109 Cd. Cd availability was assessed by measuring 109 Cd excretion in feces and by measuring the amount of label accumulated in liver and kidney. Results were as follows: (1) Although all diets were of similar nutrient composition, female rats that consumed diets containing 20% ground sunflower kernels gained significantly ( P P 109 Cd was not different ( P > 0.1) than kernels labeled exogenously: 12% versus15%, respectively. Eight days after dosing, total liver 109 Cd was 1% of the initial dose; at 20 days it was only 0.3%. The corresponding amounts in kidney were 0.1% 8 days after dosing and 0.2% 20 days after dosing. The amount of label in liver and kidney was not affected by the method of labeling the kernels. This study clearly shows that Cd from sunflower kernels is available for absorption and accumulation in tissues of the rat, although in very small concentrations.

Humans and animals develop low copper (Cu) status when fed diets containing large amounts of zinc (Zn) for an extended period. Current theory states that Zn-induced metallothionein (MT) in the intestinal mucosa binds Cu and prevents its absorption. We tested this theory by using a mouse model with a disruption in the MT gene that renders it incapable of producing functional MT-I and MT-II (MT-null). If the theory is true, then the MT-null mouse should not develop low Cu status when fed a high Zn diet. For 1 week, groups of 4-week-old MT-null and control mice were fed a diet that contained 35 mg Zn and

Transgenic mosquitoes are a potential tool for the control or eradication of insect-vectored diseases. For malaria, one possible strategy relies on the introduction of malaria-refractory transgenes into wild Anopheles mosquito populations that would limit their capacity to transmit the disease. The success of such an approach obviously depends on a variety of factors. By developing a model that integrates both population genetics and epidemiology, we explore how mosquito mating preferences and the cost and efficacy of refractoriness affects the long-term prevalence of malaria in humans subsequent to a single generation inundative release of male transgenic mosquitoes. As may be intuitively expected, mating discrimination by wild-type individuals against transgenic ones generally reduces the probability that transgenes become stably established at a high frequency in mosquito populations. We also show that in circumstances where transgenic individuals exhibit some degree of discrimination against wild-type individuals, this can favour the spread of refractory alleles and lead to a significant reduction in malaria prevalence in the human population (if the efficacy of a dominant refractory mechanism exceeds at least 75%). The existence of such a non-intuitive outcome highlights the practical value of increasing the understanding of Anopheles mating preferences in the wild as a means to harness them in the implementation of population replacement approaches. Potential strategies by which previously described mating preferences of Anopheles gambiae populations could be exploited to manipulate the mate choice of transgenic release stocks are discussed.

Because of inherent genetic and physiological characteristics, the natural concentration of cadmium in the kernels of sunflowers grown in uncontaminated soils of the northern Great Plains region of the United States is higher than in most other grains. We tested the hypothesis that a habitual consumption of sunflower kernels will increase the body burden and health effects of cadmium in humans. Sixty-six men and women who reported consuming various amounts of sunflower kernels were recruited and divided by sex and kernel consumption: those who consumed less than or equal to 1 ounce(oz)/week and those who consumed more than 1 oz/week. Cadmium intake was assessed by calculation from 7-day food diaries, cadmium burden by whole blood cadmium, red blood cell (RBC) cadmium and urine cadmium concentrations, and health effects by urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) activity and beta2-microglobulin (beta2MG). The results showed that high intakes of sunflower kernels (>1 oz/day) significantly increased the intake of cadmium (p0.05). Because normal ranges for the excretion of these protein markers have not been established, it was not possible to determine if these elevated values were meaningful. However, given the knowledge that habitual consumption of sunflower kernels with natural cadmium concentrations higher than most other food products will increase the average intake of dietary cadmium, the potential exists for an increased body burden of cadmium. Controlled feeding studies in humans should be pursued in order to determine if the body burden does indeed increase and, if so, is it a cause for concern.

The feeding of high-zinc diets to humans is often used as therapy for patients with Wilson’s disease, an autosomal recessive disorder of copper accumulation. There seem to be no outward adverse effects of this treatment; however, preliminary studies in our laboratory have shown apparent weaknesses in the intestinal wall of rats fed high-zinc diets. As a consequence, this study was carried out to determine if feeding high-zinc diets to rats would affect the ultrastructural morphology of the small intestine. The effects of treatment on copper status of the rats also were determined. Weanling male rats were fed diets containing either 35 or 350 mg of zinc/kg. After 7 weeks, blood and various tissues were collected to measure copper status indicators, and portions of the upper duodenum were excised and prepared for light and electron microscopy. Results showed that rats fed high-zinc diets had significantly lower copper status as indicated by low serum copper, serum ceruloplasmin activity, and liver copper, than rats fed normal-zinc diets. Liver superoxide dismutase or cytochrome c oxidase activities were not affected by high zinc. Observations of sections of the duodenum by electron microscopy showed that non-assembled collagen molecules of the lamina propria were more often disorganized and formed tangled masses in rats fed the high-zinc diet than in those fed normal-zinc diets. This suggests that low copper status caused by high-zinc feeding might be affecting the activity of lysyl oxidase, a copper-dependent enzyme, and thus crosslinking of the collagen molecules. However, these observations did not always correlate with low copper status. Other possible explanations include a direct competition between zinc and copper for sites on lysyl oxidase, zinc blocking of aldehyde residues on the collagen molecule, or some unrecognized process involving other enzymes or other aspects of collagen assembly. Whether such processes or affinities actually exist is still under investigation. J. Trace Elem. Exp. Med. 10: 37–46, 1997. Published 1997 Wiley-Liss, Inc.1

Zinc deficiency results in reduced testicular angiotensin-converting enzyme (ACE) activity and reduced amounts of ACE protein in the testes of young rats. In the present study, we examined the effect of zinc deficiency on the relative abundance of testicular ACE mRNA and its relationship to ACE activity over time. Forty-five male rats at 7 wk of age were placed on one of three feeding regimens: 1) a diet adequate in zinc, 2) a diet deficient in zinc and 3) a diet adequate in zinc that was fed in an amount equal to that consumed by a paired mate fed the zinc-deficient diet. Rats were killed after 3, 5 and 7 wk. Rats fed the zinc-deficient diet had significantly lower (P < 0.01) body weight gain and testis weight at each week sampled than the other groups. They also showed compromised zinc status as evidenced by significantly lower (P < 0.01) serum and testis zinc concentrations. At each period, rats fed the zinc-deficient diet had significantly lower (P < 0.01) testicular ACE activity than rats fed either of the zinc-adequate diets. Coinciding with low ACE activity, there was a lower (P < 0.01) relative abundance of ACE mRNA in the group for the zinc-deficient diet than in either of the zinc-adequate groups. The results suggest that much of the low ACE activity in the testis of rats in the latter stages of zinc deficiency is attributable to a reduction in ACE gene transcription. However, an effect of the deficiency on ACE mRNA turnover is not ruled out.

Although previous studies have shown that copper status of rats is compromised when they consume a diet with high zinc, studies using the new AIN-93G rodent diet did not show this effect. Because the new diet formulation contains components such as L-cystine and an ultratrace element (UTE) mix that might affect copper metabolism, a study was done to determine if these components interfered with the effect of zinc. A 2 × 2 × 2 × 2 factorial study was designed with two dietary concentrations of copper, 3 and 6 mg/kg of diet; with L-cystine or DL-methionine; with or without the UTE mix; and with 2 concentrations of zinc, 35 and 350 mg/kg of diet. After 5 weeks, assessments of copper status were made. Results showed that serum ceruloplasmin amine oxidase activity, a very sensitive copper status indicator, was not affected by feeding high zinc in the diet. Other status indicators such as serum copper or liver copper concentrations also were not affected by high-zinc feeding. It was concluded that the lack of an effect of high zinc on copper status when using the AIN-93G diet was not the result of using L-cystine or UTE in the diet. Dietary UTE stimulated growth in rats fed the marginal-copper diet but not in rats fed the normal-copper diet. Rats fed diets containing DL-methionine had significantly higher concentrations of liver and intestinal copper than those fed diets with L-cystine.

A series of experiments using CACO-2 cells, have been conducted to describe the cellular events occurring during Zn uptake and transcellular movement in the presence of media containing fetal bovine serum (FBS). CACO-2 cells were grown for 21 days on either T-25 cell culture flasks or semipermeable membrane inserts maintained in six-well culture plates. Experiments were then conducted using normal growth medium containing FBS, to which 65Zn was added. The rate of Zn transport in an apical to basolateral direction was much greater than the rate in the opposite direction. To study whether uptake and movement exhibited saturation kinetics, different concentrations of Zn (1–200 μ m ) were added with 65Zn. Uptake at the basolateral membrane was saturable; apical to basolateral movement, basolateral to apical movement, and uptake at the apical membrane were not. 65Zn moved apically to basolaterally at a small but constant rate regardless of the basolateral concentration of Zn. The binding ligands for Zn in the cytosol differed depending on the prior Zn status of the cell and the time postlabeling. Endogenous 65Zn was released to the apical and basolateral sides at different rates. These data confirm a previous report that uptake and transcellular movement of Zn is different at the apical and basolateral membrane, and they further show that the presence of Zn-binding ligands alters these processes.

When faced with an abundance of heavy metals in the diet, higher animals produce metallothionein (MT) in the intestinal mucosa to sequester the metals in an attempt to reduce their absorption into the body. This paper shows that this strategy may only be used for short-term exposure, and a more effective, sustainable strategy is adopted during long-term exposure. The concentration of dietary zinc was abruptly elevated and offered to rats continually for a specified period. The results showed that an abrupt change in dietary zinc caused an immediate elevation of intestinal MT concentration, which remained elevated for about 2 weeks and then began to decline. After about 5 weeks, MT concentrations in the intestines of rats fed high-zinc diets were not different from controls fed normal-zinc diets for the entire period. The concentrations of zinc in serum, liver, and kidney followed the same course as mucosal MT, elevated during the initial phase of feeding high-zinc and near control values during the latter phase of feeding. Although the rats were consuming diets with zinc concentrations about 7 fold higher than controls, and intestinal MT concentrations were not elevated, the serum and tissue concentrations of zinc were near control values. This suggests that the induction of intestinal MT may be an immediate and short-term strategy for coping with high intakes of certain metals, and that some other, more efficient mechanism is adopted during long-term exposure.

A phylogenetic study of Clivia, including the newly described species, Clivia mirabilis, recently discovered in the Northern Cape, was carried out to elucidate the relationship of this geographically isolated taxon to the remaining four species. DNA sequence data were collected from four non-coding plastid regions: the rpoBtrnC intergenic spacer, the rps16 intron, the trnL intron and the trnL-F intergenic spacer (the latter two collectively known as the trnL-F region). In the combined tree C. mirabilis is placed as sister to a clade comprising the other four taxa.

Mycobacterium avium complex (MAC) infection occurs in up to 50% of advanced-stage human immunodeficiency 1 (HIV-1) infections when the CD4 counts is50/mm³. We report the case of a 52-year-old HIV-positive patient who presented with a symptomatic, rapidly growing suprarenal abdominal aortic aneurysm. He had been diagnosed and treated for disseminated MAC infection 3 years earlier. He was treated with antiretroviral medications and had a CD4 count250 cells/mm³ and an undetectable viral load. Open repair was performed using cryopreserved homograft. Microbiologic cultures from the specimen revealed infection with mycobacterium avium. This is the first case to report a mycotic suprarenal aortic aneurysm caused by an active conversion of a latent MAC infection.

There are a number of inherited predispositions to colorectal cancer (CRC) which can be broadly categorized into two groups; those with associated polyposis, such as familial adenomatous polyposis and the hamartomatous polyposis syndromes; and those that are linked to the non-polyposis syndromes, such as hereditary non polyposis colorectal cancer (HNPCC). The genetic basis of both the polyposis and non-polyposis syndromes are reflected in the CRC population who have no apparent family history of disease. Approximately 80% of all cases of CRC are associated with chromosomal instability [1] and are likely to have mutations in the Adenomatous Polyposis Coli (APC) gene whereas the remaining 20% with microsatellite instability appears to be due primarily to epigenetic inactivation of the DNA mismatch repair (MMR) gene MLH1 [2]. The disease HNPCC accounts for somewhere between 2% and 5% of all CRCs diagnosed and is associated with a younger age of disease onset compared to the general population [3,4]. HNPCC is a disease by definition based on the Amsterdam Criteria where there need to be three cases of CRC, one of which must be diagnosed under the age of 50 years, one patient must be a first degree relative of the other two, span two generations and familial adenomatous polyposis should be excluded [5]. Modification of the Amsterdam Criteria has been ongoing since its original inception due to an increasing awareness of what constitutes this disease. HNPCC used to be known as either the Cancer Family Syndrome or Lynch Syndrome [6]. It is now accepted that families where a mutation in the DNA mismatch repair genes (MMR) MSH2, MLH1, MSH6 or PMS2 has been identified are now termed Lynch Syndrome families whereas those with no mutation are termed HNPCC [7]. The primary function of MMR genes is to eliminate base-base mismatches and insertion-deletion loops which arise as a consequence of DNA polymerase slippage during DNA replication [8]. MMR confers several genetic stabilisation functions; it corrects DNA biosynthesis errors, ensures the fidelity of genetic recombination and participates in the earliest steps of cell cycle checkpoint control and apoptotic responses [9,10]. MMR gene defects increases the risk of malignant transformation of cells, which ultimately results in the disruption of one or

The purpose of this study was to determine the availability of cadmium from the kernels of sunflowers grown in soils containing a natural abundance of cadmium. Weanling male rats were used as the experimental model. Fresh sunflower kernels containing either 330 or 780 μg Cd/kg were ground and added to a purified rodent diet at 20%. Cadmium chloride was added to purified diets without kernels. After 10 weeks, a test meal of each diet, containing 109 Cd, was fed and whole-body counting techniques were used to estimate cadmium absorption. Cadmium absorption from all diets ranged from 0.39 to 0.55%. Absorption was 30% less (P

Adult male Swiss-Webster mice were fed diets similar to AIN-93M containing 0.8, 1.7 2.5, 3.6, 4.3, 5.4, and 6.5 mg copper/kg. Significant reductions in serum copper, serum ceruloplasmin amine oxidase activity, and liver copper concentrations were observed in mice fed dietary copper concentrations lower than 2.5 mg/kg. By using nonlinear modeling of serum copper concentrations and serum ceruloplasmin amine oxidase activity, it was estimated that the minimal dietary concentration of copper to maintain maximal levels of these parameters in adult male mice was between 2.5 and 4 mg/kg diet.

Large doses of parenteral zinc (Zn) and/or the feeding of high Zn diets to animals or humans for long periods affects copper (Cu) metabolism. Previous work suggests that Zn-induced metallothionein (MT) in intestinal epithelial cells binds Cu and inhibits its absorption. This study was designed to determine the effects of treating rats with high dietary or parenteral Zn on Cu metabolism and its relationship to MT in the intestinal epithelium, liver and kidney. Six-week-old male rats were fed for one week a control diet containing 42 mg Zn and 6 mg Cu/kg. They were then divided into three groups. One group continued to receive the control diet while another received a similar diet containing 560 mg Zn/kg. A third group, fed the control diet, received a subcutaneous dose of 90 mg Zn/kg body weight every 2–3 days for the duration of the experiment. Rats from each group were killed on days 7 and 14. Low Cu status in Zn-treated rats was indicated by lower than normal serum Cu concentration, serum ceruloplasmin activity, low liver and kidney Cu concentrations and low cytochrome C oxidase activity. None of these changes, however, were related to an increase in Cu as a result of Zn-induced MT in the intestinal epithelial cell. Instead, as the MT concentrations rose, Cu concentration decreased. This study suggests that the effects of high Zn treatment on Cu status are not the result of the long-held theory that Zn-induced intestinal MT sequesters Cu and prevents its passage to the circulation. Instead, it may be caused by a direct effect of high lumenal Zn concentrations on Cu transport into the epithelial cell.

Human serum neuron-specific enolase (NSE) is a marker of neurons and of small-cell carcinoma of the lung; improved immunoassays of NSE remain an important goal. Here, we used overlapping complementary DNA (cDNA) clones for reconstruction to express full-length recombinant NSE, and also to express a set of cloned subfragments through the prokaryotic expression vectors pUEX and pUBEX. Subfragments expressed as fusion proteins were used to characterize immunogenic and antigenic regions and epitopes and, expressed as affinity matrices, to derive purified, fractionated polyclonal antibodies. NSE epitope data can be visualized with yeast enolase-1 crystal structure coordinates: The two protein sequences align almost perfectly and are 61% identical. This approach demonstrates the complementarity of cDNA expression with techniques of polyclonal antiserum and monoclonal antibody production and with chemical peptide synthesis in the refinement of immunodiagnostic reagents.

The objective of this pilot study was to investigate the acute effects on circulating lymphocyte subsets, antioxidant status, and cytokine profile after consumption of EpiCor(®) (EP) (Embria Health Sciences, Ankeny, IA, USA), a dried fermentate produced from Saccharomyces cerevisiae, using a placebo-controlled randomized crossover study design with 12 healthy adult human subjects. EP contains high levels of bioavailable antioxidants and strongly activates natural killer (NK) cells in vitro. EP consumption has been shown to increase erythrocyte hematocrit levels, boost mucosal immune protection, reduce cold/flu symptoms, reduce seasonal allergy symptoms and the need for rescue medication, and increase salivary secretory immunoglobulin A levels. This warranted further study on immune effects in humans. A within-subject analysis of data collected before and at 1 and 2 hours after consumption of a single dose of 500 mg of EP versus placebo was performed. A transient reduction in circulating T and NK cell numbers was observed 2 hours post-consumption, suggesting that homing and recirculation of these cells, as part of healthy immune surveillance, were supported by EP. The increased expression of activation markers on the CD3(-) CD56(+) NK cell population was significant for CD69 at 1 hour post-consumption (CD25, P

To test the effect of food restriction on responses to dietary copper deficiency, male weanling rats were fed two amounts of dietary copper via five dietary-intake regimens ranging from ad libitum to 70% of ad libitum intake. Copper-deficient rats exhibited characteristic signs, including depressed organ copper content, reduced activity of copper-dependent enzymes, enlarged hearts, and anemia. Food restriction attenuated the cardiac enlargement, red blood cell defects, and reduction of superoxide dismutase activity in copper-deficient rats. Mineral and enzyme assays suggested that possible mechanisms for this amelioration are the correction of copper status and/or the improvement of antioxidant status. Also, food restriction depressed serum cholesterol and enhanced cytochrome c oxidase activity in both copper-adequate and copper-deficient rats, which compensated for effects of copper deficiency. A second experiment illustrated that the mortality associated with severe copper deficiency was also inhibited by food restriction.

For sixteen years, the American Institute of Nutrition Rodent Diets, AIN-76 and AIN-76A, have been used extensively around the world. Because of numerous nutritional and technical problems encountered with the diet during this period, it was revised. Two new formulations were derived: AIN-93G for growth, pregnancy and lactation, and AIN-93M for adult maintenance. Some major differences in the new formulation of AIN-93G compared with AIN-76A are as follows: 7 g soybean oil/100 g diet was substituted for 5 g corn oil/100 g diet to increase the amount of linolenic acid; cornstarch was substituted for sucrose; the amount of phosphorus was reduced to help eliminate the problem of kidney calcification in female rats; L-cystine was substituted for DL-methionine as the amino acid supplement for casein, known to be deficient in the sulfur amino acids; manganese concentration was lowered to one-fifth the amount in the old diet; the amounts of vitamin E, vitamin K and vitamin B-12 were increased; and molybdenum, silicon, fluoride, nickel, boron, lithium and vanadium were added to the mineral mix. For the AIN-93M maintenance diet, the amount of fat was lowered to 40 g/kg diet from 70 g/kg diet, and the amount of casein to 140 g/kg from 200 g/kg in the AIN-93G diet. Because of a better balance of essential nutrients, the AIN-93 diets may prove to be a better choice than AIN-76A for long-term as well as short-term studies with laboratory rodents.

An enzyme-linked immunosorbent assay (ELISA) was developed to determine the concentration of angiotensin-converting enzyme (ACE) in the testes of rats. ACE was isolated and purified from the testes by affinity chromatography using the specific ACE inhibitor lisinopril bound to Sepharose CL-4B. Polyclonal antibodies to the purified ACE protein were produced in rabbits. A competitive antigen capture ELISA was developed by using antibody-coated polystyrene tubes as the solid phase and alkaline phosphatase covalently bound to purified ACE as the detector. This paper describes in detail the procedures for preparing the affinity gel and column, isolating and purifying ACE protein, producing and isolating the antibodies, production of the alkaline phosphatase-ACE conjugate, and the development of the ELISA. The assay was tested by determining the amount of ACE protein in rat testis as affected by zinc deficiency, a condition known to reduce ACE activity in this tissue. Preliminary results showed a direct correlation between the reduction in ACE activity and ACE protein in the Zn-deficient rats.

Cisplatin (CDDP) is a platinum coordination compound with antineoplastic properties. Cisplatin chemotherapy is known to cause serious damage to the kidney tubules and to the germinal epithelium of the testis. Results of recent investigations suggest that pretreatment with parenteral Zn will prevent some of the damage in these tissues. The present study determined the effects of pretreatment with large doses of parenteral Zn on trace element metabolism and enzyme activity in CDDP-treated rats. Treating young male rats (200 g) with intraperitoneal injections of 90 mg Zn/kg body weight prior to CDDP treatment (3 mg/kg body weight for 3 days) did not inhibit kidney damage; confirmed by elevated area and creatinine concentrations in serum of CDDP-treated rats. Serum and testicular testosterone concentrations were significantly lower in CDDP-treated rats than controls, which suggests Leydig cell damage. Zn treatment did not, however, alleviate this effect. Although angiotensin-converting enzyme activity was significantly elevated in the kidney by Zn treatment, activities in the testis and epididymis were not affected. Contrary to the suggestions that high parenteral Zn treatment protects kidneys and testes from damage, this study shows no such positive effects. However, the study demonstrated that treating rats with high concentrations of Zn and/or CDDP caused numerous changes in tissue concentrations of zinc, copper, and iron and in the activities of Zn-dependent as well as non-Zn-dependent membrane-bound enzymes.

Selenium (Se) is an essential nutrient, and soy is a major plant source of dietary protein to humans. The United States produces one-third of the world's soybeans, and the Se-rich Northern Plains produce a large share of the nation's soybeans. The present study used a rat model to determine the bioavailability of Se from a protein isolate and tofu (bean curd) prepared from a soybean cultivar we recently developed specifically for food grade markets. The soybean seeds contained 2.91 mg Se/kg. Male Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet containing 5 microg Se/kg; after 56 days, they were replenished of Se for an additional 50 days by feeding them the same diet supplemented with 20, 30, or 40 microg Se/kg from soy protein isolate or tofu. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the responses of Se-dependent enzyme activities and tissue Se contents, comparing those responses for each soy product to those for SeMet using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in dose-dependent increases in glutathione peroxidase activities in blood and liver and thioredoxin reductase activity in liver, as well as dose-dependent increases in the Se contents of plasma, liver, muscle, and kidneys. These responses indicated an overall bioavailability of approximately 97% for Se from both the protein isolate and tofu, relative to SeMet. These results demonstrate that Se from this soybean cultivar is highly bioavailable in this model and that high-Se soybeans can be good dietary sources of Se.

Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch syndrome is characterized by inactivating germline mutations in DNA mismatch repair genes resulting in an increased risk of developing an epithelial malignancy. There is considerable variability in disease expression observed in this syndrome, which is thought to be due to a combination of genetic and environmental factors. Alterations in the kinetics of methylene tetrahydrofolate reductase (MTHFR) due to the presence of polymorphisms in the MTHFR gene have been associated with an increased risk of colorectal cancer (CRC). Two common single nucleotide polymorphisms (SNPs) located within the MTHFR gene, 677 C>T and 1298 A>C, that alter the function of the encoded protein have been the focus of many studies on CRC risk outside the context of an inherited predisposition to disease. In this report, a total of 417 HNPCC participants were genotyped for the 677 C>T and 1298 A>C SNPs to determine whether there exists an association with the age of disease onset of CRC. Genotyping of both SNPs was performed by TaqMan® assay technology. Associations in disease risk were further investigated using Kaplan–Meier survival analysis and Cox hazard regression. The average ages of disease diagnosis were found to be different between individuals harbouring either one of the MTHFR polymorphisms. Both Kaplan–Meier and Cox hazard regression analyses revealed a more complex relationship between the two polymorphisms and the age of CRC onset. The Kaplan–Meier survival analysis revealed that compound heterozygotes for the two SNPs developed CRC 10 years later compared with those carrying only wild-type alleles.

Endothelial cells form the lining of blood vessels. Therefore, nutrients must cross this barrier each time they enter or leave the blood. While passing through the endothelium, nutrients may interact with intracellular zinc pools. This study was undertaken to characterize the dimensions of the zinc pools that are associated with endothelial cells. 65Zn was employed as a tracer to follow the pattern of zinc uptake and release by bovine pulmonary aortic endothelial cells that had grown into a confluent monolayer. The total cellular zinc content of the endothelial cells was calculated to be 2.48 nmol zinc/mg protein, based upon specific activity. The t 1 2 for cellular zinc turnover was 244 min. Mathematical modeling of both the uptake and the release processes demonstrated that there are two pools of zinc associated with each. A slow exchange pool was estimated to contain approximately 1.4 nmol zinc/mg protein during both influx and efflux experiments. A fast exchange pool contained 1.11 nmol zinc/mg protein during zinc efflux; zinc entering the cell was exchanged rapidly with a pool of 0.65 nmol zinc/mg protein. The efflux measurement may contain labeled ligands resulting from the catabolism of zinc biomolecules that are absent from the influx study; it is more likely to be a true estimate of the fast exchange pool.

Testicular dipeptidyl carboxypeptidase (TDC) activity, which is regulated by testosterone, increases in germinal cells of the rat as it matures. TDC activity and testosterone production are depressed in zinc-deficient rats during this period. Experiments were conducted to determine if testosterone supplements would maintain TDC activity in zinc-deficient rats. Three dietary treatments were used; zinc-deficient, fed ad libitum; zinc-adequate, pair-fed to the deficient group; and zinc-adequate, fed ad libitum. One-half of the rats in each group received daily subcutaneous injections of testosterone. Overall, TDC activity was lower in zinc-deficient rats than zinc-adequate controls. Testosterone treatment of zinc-deficient rats lowered TDC activity even further while having intermediate or no effect on activity in zinc-adequate controls. Activity of gamma-glutamyl transferase (GGT) was higher in the testis of zinc-deficient rats than in pair-fed or ad libitum-fed controls. However, only the latter was significantly different from the deficient group. Alkaline phosphatase (AP) activity was lower in the testis of zinc-deficient rats than either of the two control groups. Activities of GGT and AP were affected only marginally or not at all by testosterone treatment.

Recent studies have suggested that the induction of metallothionein synthesis in kidneys of mice by the acute administration of bismuth and other trace elements might protect against cis-diamminedichloroplatinum (II) nephrotoxicity. The present study was designed to determine the effects of dietary zinc and cis-diamminedichloroplatinum (II) on the induction of liver and kidney metallothionein and its subsequent effect on nephrotoxicity and trace element metabolism in rats. Male rats were fed diets containing 5, 20, 80, or 320 mg zinc/kg diet for 3 weeks. Each dietary group was subdivided into 3 groups. In one group, each rat received an i.p. injection of 7.5 mg cis-diamminedichloroplatinum (II)/kg b.w. All other rats received saline. During the next three days a second group of rats was pair-fed to the cis-diamminedichloroplatinum (II) injected group. A third group received no treatment and was allowed to eat ad libitum. Results showed that when dietary zinc was increased from 5 mg/kg diet to higher amounts, kidney metallothionein concentration increased twofold. cis-diamminedichloroplatinum (II) treatment increased kidney metallothionein even further, but elevated metallothionein gave no protection from the toxic effects of the drug. Serum copper concentration and ceruloplasmin activity were significantly lower with higher concentrations of dietary zinc, which indicated that these rats were mildly copper-deficient. There was a small but significant depression of superoxide dismutase activity and a highly significant increase in thiobarbituric acid reactive substances in kidneys of rats treated with cis-diamminedichloroplatinum (II) compared to either pair-fed or ad libitum controls. This supports the hypothesis that part of the mechanism for cis-diamminedichloroplatinum (II)-induced toxicity might be caused by free-radical generation. However, the data do not support the hypothesis that metallothionein induction protects the kidney from cis-diamminedichloroplatinum (II) toxicity.

Dietary copper (Cu) deficiency produces known defects in the kidney. We studied the effects of Cu deficiency on renal function and microvillar enzyme activity. Because Cu deficiency causes oxidative damage in other tissues and because of recent success in preventing cardiovascular defects of Cu deficiency with antioxidants, we also studied the effect of the hydroxyl radical (OH) scavenger, dimethyl sulfoxide (DMSO), on observed renal changes of Cu deficiency. Male, weanling Sprague-Dawley rats were fed, in a 2×2 design, diets deficient in Cu (CuD) or supplemented with Cu (CuS, 5 ppm) and water with or without DMSO (4.75%) for 35 days. Cu deficiency in CuD rats was confirmed by serum ceruloplasmin and liver, kidney and heart mineral measurements. CuD rats had lower body weights (BW), hematocrits (Hct), dry kidney weight and total body water (by bioelectrical impedance analysis) than CuS rats. They also had higher heart weights, (HW), HW/BW ratios, % heart water, serum cholesterol, total kidney weight (TKW)/BW ratio, % kidney water, serum Cl, and % body water. CuD rats had higher activities of renal microvillar angiotensin converting enzyme (ACE) and endopeptidase (EP) and lower activities of alkaline phosphatase (AP) and gamma glutamyl transferase (GGT) than CuS rats. DMSO attenuated effects of Cu deficiency on HW, HW/BW, % heart water and Hct. Though DMSO showed some independent effects on renal function, there was no interaction with Cu on TKW/BW, % kidney water, serum Cl or body water. DMSO independently increased ACE and AMP activity, independently decreased AP activity, significantly inhibited the effect of Cu deficiency on GGT activity and had no effect on EP activity. Inhibition of cardiovascular but not renal effects of Cu dificiency by DMSO suggests that there is a difference in the way Cu deficiency affects the metabolism of the two organ systems.

Dipeptidyl carboxypeptidase (DC) is highly active in the testis and epididymis of rats and increases during pubertal development. Zinc deficiency during this period depresses the activity of DC in the testis. Experiments were conducted to determine the effects of zinc deficiency on epididymal DC activity. Comparisons were made between changes seen in this organ and those observed in testis. Three dietary treatments were used; zinc-deficient, fed ad libitum; zinc-adequate, pair-fed to the deficient group; and zinc-adequate, fed ad libitum. Results confirmed that testicular DC is affected negatively by zinc deficiency. DC activity was also lower in the epididymis of zinc-deficient rats than in control rats. These effects apparently were specific relative to changes in activity of other enzymes. Alkaline phosphatase activity in the epididymis was not affected by zinc deficiency and it was depressed in the testis. Gamma-glutamyl transferase activity in the epididymis was not affected by zinc deficiency but it was elevated in the testis. The results of this study suggest that part of the effect of zinc deficiency on sexual maturity in the male rat may be caused by reduced activity of DC. This enzyme is thought to be required for maturation and development of sperm cells.

Background: Chronic Helicobacter pylori infection is the most common cause of gastric cancer. H. pylori induces oxidative stress while zinc deficiency results in increased sensitivity to it. In Ecuador, the prevalence of gastric cancer and zinc deficiency are high. We hypothesized that zinc deficiency in Ecuadorian people would cause increased H. pylori-induced inflammation in the gastric mucosa associated with lower tissue zinc concentrations. Methods: Three hundred and fifty-two patients with dyspepsia underwent endoscopy to obtain gastric mucosa biopsies. Diagnosis of H. pylori infection and its severity, histopathology, mucosal zinc concentration, and inflammation intensity were determined. Results: H. pylori-infected patients with non-atrophic chronic gastritis had lower concentrations of zinc in gastric mucosa than uninfected patients with the same type of gastritis (251.3 ± 225.3 vs. 426.2 ± 279.9 ng/mg of protein; p = .016). Considering all patients, the more severe the H. pylori infection, the higher the percentage of subjects with infiltration by polymorphonuclear (PMN) cells (p = .0001). Patients with high PMN infiltration had lower mucosal zinc concentrations than patients with low PMN infiltration (35.2 ± 20.7 vs. 242.9 ± 191.8 ng/mg of protein; p = .021). Conclusions: The degree of inflammation in H. pylori-induced gastritis appears to be modulated by gastric tissue zinc concentrations.

Selenium is an essential mineral micronutrient for animals, and significant evidence supports an association between supranutritional Se intake and a reduction in the incidence of some forms of cancer. Thus, supplemental Se intake may provide an avenue for reducing cancer incidence. However, an important issue to consider is the form of Se that should be provided in such a supplement, because the bioavailability and bioactivity of Se can vary dramatically depending on the chemical form in which it is delivered. Because wheat products are the largest source of Se in U.S. diets, the absorption of Se was evaluated in different fractions of milled wheat that exhibits very high Se levels, owing to its production on naturally Se-rich soils. An experiment was conducted to determine the bioavailability of Se from three milled fractions of high-Se wheat. The method used was the slope-ratio assay, which measures the ability of Se from the wheat fractions to regenerate Se-dependent enzyme activities and tissue Se concentrations in Se-deficient rats. The responses generated from wheat Se were compared to a standard response curve generated by feeding graded amounts of Se as sodium selenite (Na2SeO3; NaSelenite) or selenomethionine (SeMet) in an AIN-93G-Torula yeast-based diet. Results showed that Se from wheat flour ( approximately 75% extraction) was nearly 100% available by a number of measures including plasma, liver, kidney, and muscle Se concentrations and liver and erythrocyte Se-dependent enzyme activities when compared with similar measures in rats fed NaSelenite or SeMet. However, on the basis of similar criteria, Se from wheat shorts was only about 85% available and that from wheat bran was about 60% available for absorption. These results indicate that high-Se wheat products, mainly those made from refined flour alone, might be particularly well suited for use as dietary Se supplements.

The trace element copper (Cu) is a required nutrient in the diets of humans. It has been found in animal studies to be essential for efficient iron absorption and oxygen utilization and for aiding free-radical degradation. Dry beans (Phaseolis vulgaris) are potentially good sources of Cu; thus, the objective of this study was to determine the bioavailability of Cu from dry beans using the pinto bean as the source. Dry beans were obtained from a local market, cooked according to package directions, and dried. Weanling male Sprague-Dawley rats (8 groups of 8 rats each) were fed a Cu-deficient diet (AIN-93G) for 4 wk followed by 2 wk of Cu repletion with diets containing 0-6.5 mg Cu/kg diet added as CuSO 4 or with 0.6 and 1.5 mg Cu/kg incorporated into rat diets as pinto beans at 10 and 20%. Standard response curves were developed based on repletion-induced recovery of 10 indices of Cu status, including organ Cu concentrations and Cu-dependent enzyme activities, in response to increasing dietary Cu as CuSO 4 . Recovery of these variables in rats fed the pinto bean diets was compared with the standard response curve at similar levels of dietary Cu. Based on the recovery of all 10 variables, the relative bioavailability of Cu from dry beans was at least 100% of that with the highly available CuSO 4 . For 3 of the variables, liver and heart Cu concentrations and serum superoxide dismutase 3 activity, estimated bioavailability values of Cu from beans were 138, 140, and 134%, respectively, of those from CuSO 4 . We conclude that the dry pinto bean is a good source of dietary Cu with respect to both concentration and bioavailability.