Urinary zinc excretion and zinc status of patients with Β-thalassemia major

In this study, zinc status and urinary zinc excretion with and without desferrioxamine (DFO) infusion and the relationship between urinary zinc excretion and renal tubular dysfunction in thalassemia major (TM) patients were investigated. Forty TM patients were given four DFO infusions on alternate days over a 1-wk period prior to the transfusion. On each day that DFO was given, a 24-h urine collection initiated. DFO was omitted for 1-wk before the following transfusion and during the period four 24-h urine collections were performed. Twenty healthy children provided 24-h urine collection as controls. Blood samples were taken on each of two consecutive transfusion days of the patients and from the controls. Urinary zinc excretion was measured and plasma and red blood cell (RBC) zinc analysis were performed by inductively coupled plasma-atomic emission spectrophotometry. UrinaryN-acetyl-Β-D-glucosaminidase (NAG) activity and creatinine were determined in morning urine specimens. The mean plasma zinc concentration was significantly lower in the patients not given DFO compared to the values of the patients given DFO and the control group. The mean RBC zinc concentration (Μmol/g Hb) in the patients (with and without DFO) and the control group were similar. Urinary zinc excretion was significantly higher in the patients receiving DFO compared to the control group, whereas urinary zinc excretion in the patients not given DFO was not different from the controls. Urinary NAG indices (U/g Cr) were significantly higher in the patients compared to controls. Urinary zinc excretion was correlated with the urinary NAG indices.     

Assessment of gene–nutrient interactions on inflammatory status of the elderly with the use of a zinc diet score — ZINCAGE study

Although zinc plays an important role in health status of the elderly, their dietary habits in relation to zinc intake are not well documented. The main objective of the current study was the assessment of dietary zinc intake in European old populations and the investigation of its impact on plasma zinc and inflammatory cytokines concentrations, in relation to genetic markers. Within the ZINCAGE study, 819 healthy old Europeans (≥60 years old) were recruited. Plasma zinc, interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured. Genotype data were obtained for the ?174G/C polymorphism in the IL-6 gene. Dietary data were collected with a food frequency questionnaire and were used to calculate a zinc diet score. Zinc score was validated using additional dietary data (24-h recalls), in a subsample of 105 subjects. Zinc score was different among most of the European centres (P<.001), while an age-dependent decline was documented (P=4.4×10^?12). Plasma zinc concentrations were significantly correlated with the zinc score (standardized β=0.144, P=8.8×10^?5). The minor allele frequency for the ?174G/C polymorphism was f(C) 0.31. There was a significant interaction of zinc diet score and GG (?174G/C) genotype on higher plasma IL-6 levels (β±S.E.=0.014±0.0, P=.008). The main finding of our study was the detection of gene–nutrient and biochemical–nutrient interactions in a multiethnic cohort based on a common dietary assessment tool.     

Is erythrocyte alkaline phosphatase activity a marker of zinc status in humans?

The identification of an enzyme activity that responds to changes in Zn intake may serve as a useful biomarker for Zn status. Alkaline phosphatase (ALP) is a dimeric protein with each subunit containing two Zn atoms. The activity of ALP in erythrocytes (E) decreases as a result of a low Zn diet, which suggests that this enzyme may be a marker of Zn status. To investigate this further, we determined the response of E-ALP in six healthy subjects following supplementation with 50 mg Zn (4.2×RDI) daily for 4 wk. A small but significant increase in plasma Zn was observed with supplementation (p<0.05), whereas there was no significant change in E-Zn over the same period. Plasma and E-Cu showed no change. Conversely, the activity of E-ALP increased in all subjects from 1.7±0.5 to 5.9±0.7 U/g protein (mean±SE) (p<0.0001). The small change observed in plasma Zn is not biologically significant in view of the many documented factors that influence its concentration. Our data support the hypothesis that E-ALP is a marker of Zn status in humans.     

Current status of the role of Cl− ion in the oxygen-evolving complex

This minireview summarizes the current state of knowledge concerning the role of Cl⁻ in the oxygen-evolving complex (OEC) of photosystem II (PSII). The model that proposes that Cl⁻ is a Mn ligand is discussed in light of more recent work. Studies of Cl⁻ specificity, stoichiometry, kinetics, and retention by extrinsic polypeptides are discussed, as are the results that fail to detect Cl⁻ ligation to Mn and results that show a lack of a requirement for Cl⁻ in PSII-catalyzed H₂O oxidation. Mutagenesis experiments in cyanobacteria and higher plants that produce evidence for a correlation between Cl⁻ retention and stable interactions among intrinsic and extrinsic polypeptides are summarized, and spectroscopic data on the interaction between PSII and Cl⁻ are discussed. Lastly, the question of the site of Cl⁻ action in PSII is discussed in connection with the current crystal structures of the enzyme.     

Threatened species, a re-evaluation of the status of eight endemic plants of the Gala´pagos

Although still in relatively good condition, the Gala´pagos Archipelago suffers from increasing human pressures. Apart from direct actions like hunting and logging, endemic plants and animals are threatened by introduced species, and in many cases the present status of the populations is not known. The conservation status of eight plant species considered endangered was studied from literature and field surveys and the main threats were determined. Each of the eight species is endemic to only one island but in some cases is also present on nearby islets. Of these eight species, one is considered extinct, one critically endangered, and the others suffer various levels of threat. As in all island systems of the world, the main threats are introduced organisms, both plants and animals. The extinct species probably disappeared owing to invasion by Lantana camara, one of the most aggressively invasive plants of the islands, and the most endangered species is threatened by goats. The remaining species seem to be regenerating well and we can expect positive results from protection efforts. Today, only one of the eight species benefits from a direct protection action.     

Effect of zinc salts on the structure–function of actomyosin from pelagic fish

The effect of zinc salts, zinc chloride and zinc sulfate on the structure and ATPase enzyme activity of actomyosin from pelagic fish (Sardinella longiceps) has been investigated. ATPase enzyme activity decreased in the presence of both the zinc salts. The inhibitory effect is present in both pH of 7.0 and 9.0. At concentration of 1 × 10^?3 M of zinc salts, complete inhibition of ATPase enzyme activity is observed. With the increase in temperature from 25 °C to 45 °C the ATPase activity decreased by nearly 80%. The solubility profile of actomyosin in the presence of zinc salts shows a sigmoid pattern as the concentration of both the zinc salts increases. Free SH content of actomyosin decreased with the increase in concentration of zinc salts. Intrinsic fluorescence indicated significant decrease in relative fluorescence intensity of actomyosin. This indicates significant alterations in the structure of actomyosin. Analysis of secondary structure also indicates significant alteration in the α-helical content upon binding of both zinc salts.     

An infectious aetiology of insulin-dependent diabetes mellitus? Role of the secretor status

Studies of patients with insulin-dependent diabetes and their families have shown increased incidences of HLA markers B8, B15, DR3 and DR4. While these genetic predispositions are obviously important, additional factors such as environmental influences are presumed to trigger the events leading to the development of diabetes. Infectious triggers, in particular several viruses, have been suggested. The evidence from epidemiological and in vitro studies for a viral aetiology is summarized here. The significance of the recent finding of an increased proportion of non-secretors among patients with insulin-dependent diabetes is discussed in the context of other 'autoimmune' diseases for which infectious aetiologies have been proposed.     

Isohumulones modulate blood lipid status through the activation of PPARα

Isohumulones derived from hops are the major bitter compounds in beer. It was recently reported that isohumulones activated peroxisome proliferator-activated receptors (PPARs) α and γ in vitro and modulated glucose and lipid metabolism in vivo. In this study, we examined the effects of isomerized hop extract (IHE) primarily containing isohumulones in C57BL/6N male mice and found that such treatment increased their liver weight and reduced their plasma triglyceride and free fatty acid levels. Microarray analysis and quantitative real time PCR (QPCR) showed that IHE dose-dependently upregulated the expression of a battery of hepatic genes that are involved in microsomal ω-oxidation and peroxisomal and mitochondrial β-oxidation. These effects were common in both genders and very similar to those found with the PPARα agonist, fenofibrate (FF). Moreover, these effects were not found in PPARα-deficient mice. Thus, our results strongly suggest that IHE intake upregulates the expression of key genes that are involved in hepatic fatty acid oxidation, and that it ameliorates the blood lipid profile by activating PPARα.     

Does starvation influence the antioxidant status of the digestive gland of Nacella concinna in experimental conditions?

In a previous study we analysed the effect of diesel seawater contamination in the digestive gland of the Antarctic limpet Nacella concinna. We observed that antioxidant enzyme activities decreased after one-week starvation prior to the experiment, and this was considered in the analysis of the obtained results. To know whether the digestive gland oxidant-antioxidant status may be altered by starvation and experimental conditions, we evaluated the food deprivation effect in limpets from the nearshore shallow waters of Potter Cove, Antarctica. Organisms were acclimated to laboratory conditions and were divided in fed and starved groups, and maintained in these conditions during one month. Every week 20 limpets were sampled from each group. Digestive glands were dissected and kept frozen until they were processed. Superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) measured as thiobarbituric reactive substances (TBARS), protein oxidation (PO) and reduced glutathione (GSH) were measured. For both groups of limpets, SOD increased its activity in the first week of the exposure period, with a maximum in the second week. CAT activity increased significantly in the second week, only for the starved group. Similarly, GST activity also increased for starved group in the second week; but maintained this tendency for both groups until the fourth week. In fed and starved limpets, TBARS values increased significantly, during the first week and then returned to normal values. The PO levels in the starved group increased only during the first week. The GSH content, for the fed group, increased significantly after the third week. The obtained results indicate that biochemical or physiological studies conducted with N. concinna should consider the effects of food deprivation and time spent under experimental conditions.     

Nutritional status of Aureobasidium sp. ATCC 20524 for the production of β-fructofuranosidase

Sucrose at 10 to 20% (w/v) was the best carbon source for the production of -fructofuranosidase by Aureobasidium sp. ATCC 20524. At higher concentrations, it arrested growth. Glucose and fructose were also good carbon sources for the enzyme production. Yeast extract at 1.5 to 2% (w/v) was the best nitrogen source for the enzyme production and for cell growth. Addition of NaNO₃ (1 to 2%, w/v) and MgSO₄·7H₂O (0.5 to 1.5%, w/v) to the cultivation medium increased the intracellular enzymatic activity. The total enzymatic activity and cell growth reached 1.2×10⁴ U/flask and 2.5 g dry cell/flask, respectively after 48 h.Sachio Hayashi, Yoshihiko Shimokawa, Masaharu Nonoguchi, Yoshiyuki Takasaki and Kiyohisa Imada are with the Department of Industrial Chemistry, Faculty of Engineering, Miyazaki University, 1-1 Nishi, Gakuen Kibanadai, Miyazaki, 889-21 Japan. Hideo Ueno is with the Nippon Oligo Corporation, 588 Izumisawa, Jyohana-chyo, Tonami-gun, Toyama, 939-18, Japan.     

Binding of γ-crystallin substrate prevents the binding of copper and zinc ions to the molecular chaperone α-crystallin

α-Crystallin is a small heat shock protein and molecular chaperone. Binding of Cu2+ and Zn2+ ions to α-crystallin leads to enhanced chaperone function. Sequestration of Cu2+ by α-crystallin prevents metal-ion mediated oxidation. Here we show that binding of human γD-crystallin (HGD, a natural substrate) to human αA-crystallin (HAA) is inversely related to the binding of Cu2+/Zn2+ ions: The higher the amount of bound HGD, the lower the amount of bound metal ions. Thus, in the aging lens, depletion of free HAA will not only lower chaperone capacity but also lower Cu2+ sequestration, thereby promoting oxidation and cataract.     

Measurements of urinary leptin and capillary leptin: alternative tools for the assessment of the leptin status?

OBJECTIVES: The aim of this study was to check whether leptin is reliably measurable in urine samples of children, adolescents, and adults and to examine whether capillary leptin measurements can be utilized as an alternative tool to assess the leptin status. METHODS: Two studies were performed. In both studies, leptin was quantified by an ultrasensitive and highly specific enzyme immunoassay (ELISA; R & D Systems). Anthropometric measures were taken from all study subjects, and body fat was calculated using skinfold thickness measurements. In study 1, leptin was analyzed in 24-hour urine samples of 155 healthy children and adolescents and 26 healthy adults after a methodological modification of the assay necessary for urine analysis. In study 2, venous and capillary blood samples were collected in 26 healthy adults within 10 min on the same day. RESULTS: After adapting the assay system to urine matrix, the detection range was 20-160 pg/ml. Only in 2 of 181 urine samples reproducibly measurable urinary leptin concentrations in the lowest detection range were found. In study 2, a close correlation was found between log capillary and log venous leptin concentrations (r = 0.98, p < 0.001) and between log capillary as well as log venous leptin levels and percent body fat (r = 0.86, p < 0.001). CONCLUSIONS: Our results based on one of the most specific and sensitive ELISAs currently available show that leptin is generally undetectable in the urine from healthy children, adolescents and adults. Thus, urinary leptin excretion cannot be used as a noninvasive marker of the leptin status. Our findings in healthy adults show that the merely moderately invasive determination of capillary leptin allows a reliable assessment of the individual leptin status and may be used instead of venous leptin as a biochemical indicator of body fatness.     

Getting to the guts of the matter: The status and potential of ‘omics’ research of parasitic protists of the human gastrointestinal system

Parasitic protists are a major cause of diarrhoeal illnesses in humans globally. Collectively, enteric pathogens exceed all other forms of infectious disease, in terms of their estimated global prevalence and socioeconomic impact. They have a disproportionately high impact on children in impoverished communities, leading to acute (diarrhoea, vomiting, dehydration and death) and chronic disease (malabsorption, malnutrition, physical and cognitive stunting and predisposition to chronic, non-communicable disease) consequences. However, historically, investment in research and disease control measures has been disproportionately poor, leading to their current classification as neglected pathogens. A sound understanding of their biology is essential in underpinning detection, treatment and control efforts. One major tool in rapidly improving our knowledge of these parasites is the use of biological systems, including ‘omic’ technologies. In recent years, these tools have shown significant success when applied to enteric protists. This review summarises much of this knowledge and highlights the significant remaining knowledge gaps. A major focus of the present review was to provide a perspective on a way forward to address these gaps using advanced biotechnologies.