Zinc Group Research Articles

Effect of tooth preparation and bonding agents on cementation of metal full crown

Objective To find out the effect of tooth preparation and bonding agents on cementation of metal full crown,to provide research basis for clinical practice of full crown restoration .Methods 60 dissociation teeth were randomly divided into six groups ,10 teeth in each group .Different adhesive materials or different polymerization angle were used in different groups ,the six groups were 3 polymerization angle zinc group ,3 polymerization angle glass ionomer group,3 polymerization angle resin cement group ,5 polymerization angle zinc group ,5 polymerization angle glass ionomer group ,and 5 polymerization angle resin cement group .In the first three groups ,polymerization angle was 3,and in the latter three groups ,polymerization angle was 5.The retentive force values of all groups were tested and compared.Results The metal crown retentive force of 3 polymerization angle zinc group[（198.5 ±11.6）N]was sig-nificantly better than that of 5 polymerization angle zinc group[（138.2 ±14.1）N]（t=7.46,P〈0.05）.Polymeriza-tion angle showed no statistically significant effect on metal crown retentive force values of glass ionomer groups and resin cement groups （t=1.52,2.03,all P〉0.05）.Bonding zinc retention of 3 degree of polymerization group was （198.5 ±11.6）N,glass ionomer and resin cements were （302.7 ±19.2） N and （352.7 ±21.8） N.Bonding zinc retention of 5 degree of polymerization group was （138.2 ±14.1）N,glass ionomer and resin cements were （317.4 ± 23.8）N and （362.9 ±22.6） N.Different adhesives showed statistically significant effects on metal crown retentive force values of 3 polymerization angle groups and 5 polymerization angle groups （F=7.88,8.42,all P〈0.05）. Conclusion A suitable adhesive,standard operation can get the best cementation effect ,and improve clinical repair effect. Key words: Tooth preparation; Dental cements; Crowns; Metals; Cementation

Suppression of placental metallothionein 1 and zinc transporter 1 mRNA expressions contributes to fetal heart malformations caused by maternal zinc deficiency.

Zinc has been implicated to have a protective role against heart malformations during fetal development. Metallothionein 1 (MT-1) and zinc transporter 1 (ZnT-1) are two major metabolic factors that are associated with zinc metabolism. The present work aimed to investigate the association of placental MT-1 and ZnT-1 expressions with fetal heart malformations resulting from maternal zinc deficiency. Sprague-Dawley female rats were randomly divided into five groups of extremely low-zinc, low-zinc, moderately low-zinc, marginally low-zinc and normal zinc (n=9-12), and were fed diets with controlled zinc content at 1.0±0.3, 8.4±1.8, 15.4±2.8, 22.4±4.1 and 29.4±5.3 [mean±standard deviation (SD)] mg of zinc/kg, respectively, from day 25 of preconception until day 19 of gestation. The female rats were bred, their fetuses were harvested at day 19 of gestation after killing the dams, and fetal hearts were morphologically examined. Zinc concentration and alkaline phosphatase (ALP) activity in maternal venous blood sera were tested, and MT-1 and ZnT-1 mRNA expressions in the placenta were assayed. Zinc concentrations and ALP activities in the blood were low in all zinc-deficient diet groups in a dose-dependent fashion. The incidences of heart malformations were increased, and the levels of placental MT-1 and ZnT-1 mRNA expressions were decreased in the extremely low-zinc, low-zinc and moderately low-zinc groups compared with the normal zinc group. Specifically, mRNA levels of placental MT-1 or ZnT-1 were significantly decreased and were lower than the specific threshold values in the fetuses with heart malformations but not in the fetuses without heart malformations in all the groups. These data indicate that maternal zinc deficiency resulted in an elevated incidence of fetal heart malformations, which was associated with significant decreases in placental MT-1 and ZnT-1 mRNA expressions to the levels below the threshold values that may be a crucial factor to determine the presence of fetal heart malformations.

Zinc supplementation for neonatal hyperbilirubinemia: a randomized controlled trial.

To determine the efficacy of oral zinc for treatment of idiopathic neonatal hyperbilirubinemia in near-term and term (35-41 weeks) neonates. Randomized placebo-controlled trial. Tertiary-care teaching hospital. Eighty newborns with idiopathic neonatal hyperbilirubinemia. Neonates were randomized to receive either oral zinc sulfate (10 mg/d) or placebo for 7 days. Primary: total serum bilirubin levels at 48 (±12) h, 96 (±12) h and 144 (±12) h after intervention. Secondary: duration of phototherapy, and serum zinc and copper levels. Baseline mean (SD) total serum bilirubin levels were 14.8 (3.8) and 14.4 (3.5) mg/dL in zinc and placebo groups, respectively. No significant differences were observed in total bilirubin levels between the two groups after the intervention. Mean (SD) total serum bilirubin levels in zinc and placebo groups were 13.9 (2.5) vs. 13.4 (1.9) mg/dL (mean difference 0.566; 95% CI -0.535, 1.668, P=0.038) at 48 h, 13.1 (2.7) vs. 12.8 (2.3) mg/dL (mean difference 0.234; 95% CI -1.011, 1.479, P =0.708) at 96 h and 8.0 (2.0) vs. 8.6 (1.2) mg/dL (mean difference -0.569, 95% CI -1.382, 0.242, P=0.166) at 144 h. Although the mean duration of phototherapy in the zinc group was less by 21.3 h (95% CI 11.6, 30.9, P=0.052), the difference was not significant. Post-intervention, serum zinc levels were significantly higher in the zinc-supplemented group while serum copper levels were comparable between the two groups. Oral zinc sulfate, in a dose of 10 mg/day, is not effective in the management of idiopathic neonatal hyperbilirubinemia.

Zinc Supplementation Reduces Recurrent Acute Lower Respiratory Infection (ALRI)

Introduction: Pneumonia is a frequent and serious human illness. In Bangladesh, Acute Lower Respiratory Infection (ALRI) is a major cause of death among young children. Childhood mortality can be reduced by 50% with detection and early treatment of illness with antibiotics and immunization. Zinc plays an important role in the optimal function of the immune system by reducing the risk, severity and duration of infectious diseases. Zinc supplementation improves health and cell mediated immunity. Objectives: This study is aimed at documenting effect of zinc supplementation in preschool children on reducing ALRI. Methods: This was a double blind random control trial interventional study among180 child, conducted at Comilla CMH, from January 2010 to December 2011. The children aged 6-60 months were selected randomly for comparison of effect of Zinc and Vitamin B-Complex on ALRI. Results: In the study population, male to female ratio was 1.05:1. Baseline average age was 32 months and weight for height was 92% Of NCHS mean. It was found that 89% children completed immunization as per EPI schedule, the rest 11% were partially immunized. Twenty nine percent children had family history of Atopy. This study showed 15 episodes of ALRI in Zinc group in the control B-Complex group (1.09episodes/child/year) during the six months follow-up. There was no association of ALRI with sex. The male female ratio in this respect was 1.07:1. In this study there was statistically significant and clinically important (67%) reduction of episodes of ALRI in oral Zinc supplement group. Conclusion: This finding strongly suggests that oral supplement of Zinc reduces episodes of ALRI in children. DOI: http://dx.doi.org/10.3329/jafmc.v9i1.18736 Journal of Armed Forces Medical College Bangladesh Vol.9(1) 2013: 84-89

Oral zinc supplements are ineffective for treating acute dehydrating diarrhoea in 5–12‐year‐olds

Many countries have guidelines recommending the use of oral zinc in acute dehydrating diarrhoea in children aged 2 months to 5 years of age, but no guidelines exist for older children. This study tested how effective existing recommendations are in children from 5 to 12 years of age. Children hospitalised with acute dehydrating diarrhoea (n = 134) were randomised to receive 40 mg of oral zinc sulphate tablets or a placebo for 14 days. The primary outcome variable was the time taken for diarrhoea to stop. Secondary outcome variables included time taken for rehydration, duration of hospitalisation and recurrence of diarrhoea in the next 3 months. The median time for resolution of diarrhoea was 60 h in both groups. The zinc group was marginally better, but not statistically significant, for resolution (hazard ratio = 0.89, 95% CI 0.63-1.24), rehydration (hazard ratio = 0.93, 95% CI 0.66-1.32) and hospitalisation (hazard ratio = 0.94, 95% CI 0.67-1.34). The risk ratio of recurrence for zinc versus placebo (95% CI) was 0.65 [0.37-1.23] [p = 0.11]. Daily zinc supplements (40 mg for 14 days) in children aged 5-12 years with acute dehydrating diarrhoea did not shorten the duration of diarrhoea or reduce subsequent episodes. Further adequately sized, community-based trials are needed.

Zinc status and dietary intake of pregnant women, Alexandria, Egypt

Deficiencies of protein, energy, and micronutrients are highly prevalent in developing countries and have major effects on pregnancy outcome. Low dietary intake is the most common reason for zinc deficiency. The present research is part of a larger double-blind randomized-controlled trial to evaluate the effect of zinc supplementation on the pregnancy outcome. The aim of the present study was to assess the zinc status and dietary intake of zinc and other macronutrients and micronutrients among pregnant women in Alexandria, Egypt. Participants were pregnant women attending two antenatal care centers that serve low-income and middle-income pregnant populations. A total of 1055 healthy pregnant women aged 20-45 years were assessed for eligibility. Of these, only 675 had serum zinc level below the median for the gestational age. They were assigned randomly to one of three parallel groups. Zinc supplements were provided from 16 weeks until delivery. A subsample of 100 women was assessed for their dietary intake. A questionnaire interview was used to collect basic socioeconomic and data on current pregnancy and labor. Dietary data were collected using the 24-h recall method and a food frequency questionnaire. The nutritive value of the daily diet was computed using the Egyptian food composition tables. The blood hemoglobin level, serum zinc level, and fasting blood sugar were determined. Zinc deficiency was detected among 53.5% of the sample. Dietary intake of zinc was low, representing 59.4, 59.4, and 62% of the recommended dietary allowance (RDA) for the zinc group, zinc plus multivitamins, and the placebo group, respectively. The iron intake was below 50% of the RDA. Protein intake was less than 70% of the RDA. The mean intakes of fat were 191.97, 211.8, and 196.3 g/day for the three groups. The mean energy intake represented 51.1, 53.5, and 49.8% of the RDA. Except for carbohydrate intake, the dietary intake of all macronutrients and micronutrients was low. The lowest intake was of iron (below 50% of the RDA). Zinc and protein intake represented less than 70% of the RDA. The overall energy intake was around 50% of the RDA. Nutritional health education should be used as a preventive approach to allow the large sector of the low-income population to maximize the use of the limited resources in the best way. In women at high risk of zinc deficiency, zinc supplementation should be added to the routine supplements.

Comparison of thymulin activity to other measures in marginally zinc deficient rats (1043.11)

Activity of the thymus derived, immunoregulatory peptide thymulin has shown high sensitivity to zinc status in humans. However, this research has generally been done for people with the confounding effects of various health issues. In contrast, a study was done on healthy, semi‐mature growing rats where the only variable was adequate zinc status versus a short term, moderate restriction of zinc intake. After 2 weeks of being fed a diet with 5 ppm zinc, rats showed a mean serum zinc value that was 31% lower than for rats fed 27 ppm zinc. A much bigger mean percent difference of 61% was seen for serum thymulin activity. This activity was determined by a rosette formation assay that uses sheep erythrocytes plus spleen cells from thymectomized mice. Activity was restored to 100% of normal in vitro by adding zinc to the assay. Body weight was lower in the rats fed lower zinc (187 + 5 g vs 242 + 13), but total food intake was not much lower, and was the same per body weight. Serum extracellular superoxide dismutase activity was 18% lower in the low zinc group, and serum 5’‐nucleotidase activity was 26% lower. In addition, liver metallothionein in the low zinc group was about 27% lower than in the zinc adequate group. In conclusion, in rats, a marginal zinc deficiency, with no other confounding factors,produced a larger effect on thymulin activities than on a number of other parameters.

Zinc supplement in reduction of relapses in children with steroid sensitive nephrotic syndrome.

To determine whether Zinc supplementation could reduce relapse rate in children with nephrotic syndrome. Randomized-controlled trial. National Institute of Child-Health and The Kidney Centre, Karachi, from January 2008 to June 2009. Sixty nephrotic children aged 2 - 15 years were selected. Baseline data including age, number of infections and relapses during pre and post study one year were recorded. Randomization was done to divide into Zinc group (Zg) to receive Zinc versus placebo (Pg) for 6 months. Relapses and infections were treated with standard therapy. T-test and chi-square tests were used to compare the mean values and proportions respectively with significance at p < 0.05. Among 60 children, 54 completed trial (Zg = 25, Pg = 29). Forty (74%) were males and 14 (26%) females. Mean age, pre study relapses and Zinc level in the two groups were similar. Overall, infections and relapses were observed in 43 (79.62%) and 17 cases (31.48%) respectively. There was no significant difference in frequency of infections and mean infection rate in Zg (20, 80% and 1.92 ± 1.47) compared to Pg (23, 79.3% and 2 ± 1.53, p = 0.950). Relapses occurred in 7 (28%) in Zg compared to 10 (34%) in Pg which was not significant (p = 0.609). Mean infection and relapse rate per patient per year (PPPY) in Zg was 1.92 ± 1.47and 1.14 ± 0.37 compared to 2 ± 1.53 and1.3 ± 0.48 in Pg respectively (p=0.846, 0.464). Pre study relapses in two groups were similar (Zg vs. Pg = 96 vs. 96.6%) whereas post study relapses in Zg were lower (7, 28%) compared to Pg (10, 34.5%). Post study mean relapse rate in Zg was 1.14 ± 0.37 PPPY compared to 2.71 ± 1.11 in pre study (p = 0.005). In Pg, post study mean relapse rate PPPY was 1.30 ± 0.48 compared to 1.70 ± 0.48 in pre study period (p = 0.037). Relapse rate reduction was 43% after Zinc supplementation compared to 27% reduction in placebo. Metallic taste was observed in 10% of cases. Zinc supplementation was helpful in reducing relapses in nephrotic syndrome.

Zinc or Albendazole Attenuates the Progression of Environmental Enteropathy: A Randomized Controlled Trial

Environmental enteropathy (EE) is a subclinical condition among children in the developing world, characterized by T-cell infiltration of the small-bowel mucosa and diffuse villous atrophy. EE leads to macronutrient and micronutrient malabsorption and stunting, with a resultant increased risk for infection and reduced cognitive development. We tested the hypothesis that zinc and albendazole treatments would reduce the severity of EE in rural African children. In a randomized, double-blind, placebo-controlled trial in rural southern Malawi, asymptomatic children, 1 to 3 years old and at high risk for EE, received either a single dose of albendazole, a 14-day course of 20 mg zinc sulfate, or a placebo. Subjects were given the dual-sugar absorption test, and the ratio of lactulose to mannitol (L:M) in urine was used to determine the severity of EE at baseline and 34 days after completion of the assigned regimen. The primary outcome was the change in the L:M. A complete set of urine samples was obtained from 222 of 234 children enrolled and analyzed. The mean baseline L:M was 0.32 ± 0.18 among all children and did not differ among groups (normal L:M range, <0.12). At the end of the study, the L:M ratio had increased more in the placebo group (0.12 ± 0.31) than in the zinc group (0.03 ± 0.20; P < .03) or the albendazole group (0.04 ± 0.22; P < .04). Treatment with zinc or albendazole protects against a significant increase in the L:M ratio, a biomarker for EE, in asymptomatic rural Malawian children. These findings could provide insight into the etiology and pathogenesis of EE. Clinicaltrials.gov Number: NCT01440608.

To Study the Role of Zinc Supplementation on Growth of Low Birth Weight Infants

This was a randomized controlled trial undertaken to study the role of zinc supplementation on growth of low birth weight infants (b.wt≤2500 gm). Out of 120 LBW infants, 23 were excluded due to loss of follow up. The remaining 97 LBW eligible neonates were randomized in to 2 group (zinc & control group), zinc group were given zinc supplementation at a dose of 2 mg/kg/day for 8 weeks from enrollment. They were then followed up every 4 weeks up to 8 weeks. At each visit, detail anthropometry including e weight, length, and head circumference were recorded at each visit. The infants in the zinc group had significantly higher weight gain (p<0.000), length gain (p<0.000), linear growth velocity and head circumference at 8 weeks. We concluded that zinc supplementation at 2 mg/kg/day for 8 weeks in LBW infants improves their growth during infancy.

EFFICACY OF ORAL ZINC SULFATE INTAKE IN PREVENTION OF NEONATAL JAUNDICE

Introduction:Jaundice is considered as a common clinical condition during infancy. Prevention of severe hyperbilirubinemia (jaundice) is safer and easier than current therapies, like phototherapy or blood exchange. In some animal studies, zinc was found effective in reducing jaundice. In this study we evaluated the effect of zinc sulfate on neonatal hyperbilirubinemia. Materials and Methods: This randomized, double-blind clinical trial was performed on healthy term (35 weeks of age and more) neonates. Eligible newborns were randomly allocated to two groups: group A (receiving zinc sulfate, n=57) and group B (receiving placebo, n=74). They were screened for indirect bilirubin by BiliCheck at the end of the first, third and seventh day of age. We evaluated various characteristics such as weight, clinical signs, maternal and neonatal histories, and laboratory results. Results: Mean bilirubin values of the 3rd and 7th day were determined as (12.9±3 vs. 12.6±2 mg/dl, p=0.473), and (12.4±3 vs. 12.4±4, p=0.989), respectively. The incidence of hyperbilirubinemia (Bil>15) among group A and group B was reported 26% and 22%, respectively. The rate of admission due to hyperbilirubinemia and phototherapy was significantly higher among the newborns in placebo group, (p=0.043). Weight gain between the 3rd and 7th day of infant’s age was more significant in the zinc group, (p=0.039). Conclusion:The current study showed that the administration of zinc sulfate neither affected hyperbilirubinemia, nor delayed the jaundice appearance; although fewer admission and phototherapy duration were reported in the zinc group in comparison with the placebo group. Weight gain between the 3rd and 7th day was more significant in the zinc group.

To Study the Role of Zinc Supplementation on Growth of Low Birth Weight Infants

This was a randomized controlled trial undertaken to study the role of zinc supplementation on growth of low birth weight infants (b.wt≤2500 gm). Out of 120 LBW infants, 23 were excluded due to loss of follow up. The remaining 97 LBW eligible neonates were randomized in to 2 group (zinc &amp;amp; control group), zinc group were given zinc supplementation at a dose of 2 mg/kg/day for 8 weeks from enrollment. They were then followed up every 4 weeks up to 8 weeks. At each visit, detail anthropometry including e weight, length, and head circumference were recorded at each visit. The infants in the zinc group had significantly higher weight gain (p&amp;lt;0.000), length gain (p&amp;lt;0.000), linear growth velocity and head circumference at 8 weeks. We concluded that zinc supplementation at 2 mg/kg/day for 8 weeks in LBW infants improves their growth during infancy.

Impact of Oxidative Stress and Lipid Peroxidation Induced by Lambdacyhalothrin on P450 in Male Rats: The Ameliorating Effect of Zinc

The present study was designed to investigate the effect of lambda-cyhalothrin (LCH) on lipid peroxidation, oxidative stress biomarkers and the activity of Cytochrome P450 in male rats and the protective role of zinc. LCH was administrated orally to rats at dose 2.6 mg/kg b.wt. (Which represents 1/10 LD 50 ) with 3 doses per week for 6 weeks (dose period). Rats were divided into four groups, eight rats for, each: (I) control group, (II) zinc group (Zn dose 227 mg/l in drinking water), (III) LCH-treated groups and LCH-Zn group (IV) as in group II and III. The present results demonstrated that LCH induced significant alteration in the activity of antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione-s-transferase, GST; glutathione peroxidase, GPx), glutathione reduced (GSH) and lipid peroxidation (LPO) levels and decreased cytochrome P 450 (P 450 ) activity in plasma of male rats. In contrast, zinc-LCH treatment showed insignificant difference, compared to control results, regarding LPO, GST, CAT and P 450 . LCH induced oxidative stress, lipid peroxidation and reduced P450 activity in the plasma of male rats. The overall results reveal the pronounced ameliorating effect of zinc in LCH-intoxicated rats.

Effect of Zinc Supplementation on Viral Response in Patients with Chronic Hepatitis C and Beta Thalassemia Major, A Pilot Study

Zinc deficiency has been reported in patients with both hepatitis C and beta thalassemia major. Zinc supplementation in addition to antiviral therapy of chronic hepatitis C has been accompanied by some success in patients with chronic hepatitis C. The aim of the present pilot study is to determine the effect of 30 mg elemental zinc on biochemical and virological response in a population of patients with chronic hepatitis C with beta thalassemia major. A prospective, double blind,placebo controlled trial included 40 patients being treated with Pegylated interferon Alfa (Peg IFN-α) and ribavirin. Biochemical and virological parameters and plasma zinc levels were determined before starting treatment. Patients were randomly selected to receive either zinc or a placebo in addition to Peg IFN-α and ribavirin for a period of one year. AST, ALT, sustained viral response (SVR), and zinc levels were measured after treatment.Of the original 40 eligible patients, eight withdrawn from the study and 32 patients completed the study; 16 in the zinc group and 16 in the placebo group. Analysis of the data shows that there is no difference between the two groups in AST, ALT, SVR or zinc level following one year of treatment (p=0.224, p=0.616, p=0.670, p=0.999, respectively). The results of this study indicate that using 30 mg/day elemental zinc did not significantly improve the outcome of treatment in thalassemia patients with chronic hepatitis C. In future studies, we recommend trying higher doses zinc in patients with hepatitis C who had beta thalassemia major.

Comparative evaluation of remineralization, fluoride release and physical properties of conventional GIC following incorporation of 1% and 2% zinc acetate: An in vitro study

Context: Modern concepts of operative dentistry, popularly known as Minimal intervention dentistry, propose that only the infected dentin should be removed, leaving the affected dentine that has the potential to remineralize. Mineralization of the tooth structure left in the cavity is likely to occur due to the application of fluoride- releasing material such as glass ionomer cement (GIC). Aim: The aim of this study was to evaluate whether the remineralizing potential of GIC can be enhanced with the addition of zinc acetate. Study Design: An experimental in vitro intergroup randomized control trial. Materials and Methods: This study consisted of three groups. Group I was conventional GIC, Group II was GIC with 1% zinc acetate and Group III was GIC with 2% zinc acetate. Thirty human premolars (10 in each group) extracted for therapeutic reasons were used in the first part of this study. Standardized class V cavities were prepared on the buccal and lingual surfaces. Teeth were sectioned longitudinally to get one buccal and one lingual half, in which one half was used as the control and the other half was used as the test specimen. Artificial caries- like lesions were produced and subsequently restorations of experimental specimens were performed. The depth of demineralization and remineralization were photographed under a polarized light microscope and quantified using a computerized imaging system. In the second part of the study, fluoride ions released were measured after 24 h and 7 days using an ion sensitive electrode. In the third part of the study, the setting time was calculated using Vicker's apparatus, as the time elapsed from the beginning of mixing till the time when the needle could no more make a circular indentation on the cement. In the fourth part, specimens prepared using Teflon moulds of standardized dimensions were subjected to shear bond strength analysis using a universal testing machine. Statistical Analysis: The obtained results were subjected to statistical analysis using Student's paired and unpaired 't' test, One way ANOVA, Post hoc Tukey's test. Results: In part one of the study, Group III showed the highest amount of remineralization, followed by Group II. All the groups showed statistically highly significant (P < 0.001) zones of remineralization; the difference between the groups was statistically highly significant (P < 0.001) as well. Part two of the study showed that fluoride release was highest in Group III, the difference being statistically highly significant from Group II and Group I at both the time intervals (P < 0.001). However, the amount of fluoride ions released on the 7 th day were lesser than that at 24 h in all the groups (P < 0.001). Parts three and four of the study showed that there was no statistically significant difference between the groups with respect to setting time and shear bond strength (P = 0.82 and 0.64, respectively). Conclusions: Incorporation of zinc acetate to glass ionomer at 2% w/w was effective in enhancing the remineralization property and fluoride release of the cement without affecting its setting time and shear bond strength.

The Impact of Dietary Zinc Oxide on the Bacterial Diversity of the Small Intestinal Microbiota of Weaned Piglets

Dietary zinc oxide is often used in pharmacological concentrations to promote health as well as performance of weaned piglets due to its bacteriostatic effects. This study was conducted to provide an in depth analysis of the bacterial composition in weaned piglets fed different amounts of dietary zinc oxide. Piglets were fed diets containing 57 (low), 164 (medium) or 2425 (high) mg/kg dietary zinc. Zinc above the basal dietary level was supplied from analytical grade zinc oxide (ZnO). DNA was extracted from stomach and ileum digesta samples of 32 and 53d old animals (n=4 per group) and used to generate bar-coded 16S ribosomal DNA amplicons for deep sequencing analysis. A total of 9 phyla, 40 orders, 75 families and 328 genera were detected in 8.76 x 105 sequencing reads. Firmicutes, Bacteroidetes and Proteobacteria were the dominant phyla, but no significant differences between treatment groups were observed. Lactobacillales (16.3-59.9%), Bacteroidales (2.2-59.1%), Clostridiales (0.05-70.2%) and Selenomonadales (2.6-17.5%) were found as the dominating order. Noteworthy changes on the order level were found for numerically or significantly increased ratios of Clostridiales, but significantly decreased Lactobacillales in the high dietary zinc group. The bacterial diversity for the high dietary zinc diet was significantly higher for the total microbiota than the medium or low zinc diet. However, Lactobacillales diversity decreased, while Clostridiales and Enterobacteriales diversity increased significantly. Principal component analysis confirmed changes in the microbiota, most notably for the high dietary zinc treatment. This study has shown that pharmacological doses of high dietary zinc can drastically alter the bacterial composition and development of the microbiota in weaned piglets. The quantitative shift of bacterial groups due to high dietary zinc was most pronounced one week after weaning, while the more developed microbiota in older animals seemed to be able to adapt to high concentrations of dietary zinc.

Increased stem cell marker expressions during the peri-implantation period in the rat endometrium: constructive role of exogenous zinc and/or progesterone.

Background. The aim of this study is to determine the effects of zinc and/or progesterone via the expression of αvβ5 integrins and Vitronectins and embryonic stem cell markers during the peri-implantation period. Methods. Four experimental groups were organized. All subjects were mated with males of the same strain to induce pregnancy; after 5 days, zinc and/or progesterone were administered. Blood levels of zinc and progesterone were determined on the sixth day and endometrial tissues were obtained in order to evaluate the immunohistochemical expression of integrins and embryonic stem cell markers. Results. The αvβ5 integrin and vitronectin expression increased in the zinc group compared with the control group and no difference in the progesterone group and zinc + progesterone group. Expression of Klf-4, Sox-2, and c-Myc was found to be increased in the zinc group compared to controls, while no difference was determined between the progesterone, zinc + progesterone, and control groups. Distinctively, expression of the embryonic stem cell marker Oct-4 was increased in all of the experimental groups. Conclusions. Expression of αvβ5 integrin, vitronectin, and embryonic stem cell markers might be increased by the administration of zinc. Our results suggest that zinc could be useful in the induction of implantation rates.

Zinc supplementation reduces morbidity and mortality in very-low-birth-weight preterm neonates: a hospital-based randomized, placebo-controlled trial in an industrialized country

Zinc plays a pivotal role in the pathogenesis of many diseases and in body growth. Preterm neonates have high zinc requirements. The objective of the study was to investigate the efficacy of zinc supplementation in reducing morbidity and mortality in preterm neonates and to promote growth. This was a prospective, double-blind, randomized controlled study of very-low-birth-weight preterm neonates randomly allocated on the seventh day of life to receive (zinc group) or not receive (control group) oral zinc supplementation. Total prescribed zinc intake ranged from 9.7 to 10.7 mg/d in the zinc group and from 1.3 to 1.4 mg/d in the placebo control group. The main endpoint was the rate of neonates with ≥ 1 of the following morbidities: late-onset sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, periventricular leucomalacia, and retinopathy of prematurity. Secondary outcomes were mortality and body growth. We enrolled 97 neonates in the zinc group and 96 in the control group. Morbidities were significantly lower in the zinc group (26.8% compared with 41.7%; P = 0.030). The occurrence of necrotizing enterocolitis was significantly higher in the control group (6.3% compared with 0%; P = 0.014). Mortality risk was higher in the placebo control group (RR: 2.37; 95% CI: 1.08, 5.18; P = 0.006). Daily weight gain was similar in the zinc (18.2 ± 5.6 g · kg⁻¹ · d⁻¹) and control (17.0 ± 8.7 g · kg⁻¹ · d⁻¹) groups (P = 0.478). Oral zinc supplementation given at high doses reduces morbidities and mortality in preterm neonates. This trial was registered in the Australian New Zealand Clinical Trial Register as ACTRN12612000823875.

Effects of zinc supplementation on efficacy of antidepressant therapy, inflammatory cytokines, and brain-derived neurotrophic factor in patients with major depression

ObjectiveZinc is found in abundance in the human brain. Patients with depression may have decreased consumption of food sources rich in zinc, and zinc supplementation may have a potential influence on depressive symptoms. However, clinical trials on the effect of zinc supplementation in depression are limited. The objective of the present study was to determine the effect of zinc supplementation on efficacy of antidepressant therapy. Furthermore, the effect of zinc on plasma levels of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and brain-derived neurotrophic factor-a (BDNF-a) were assessed.DesignA single-center, randomized, double-blind, placebo-controlled trial of zinc supplementation was conducted in patients with DSM-IV major depression. Forty-four patients of both sexes aged 18–55 years were recruited for this study from a university hospital. The zinc-supplemented group received zinc sulfate (25 mg elemental Zn/day) orally in addition to their selective serotonin reuptake inhibitor antidepressants for 12 weeks. Symptoms were evaluated using the Hamilton Depression Rating Scale (HDRS) on arrival, weeks 6 and 12. Plasma levels of IL-6, TNF-α and BDNF-a were measured at baseline and at the end of study.ResultsTwenty patients in zinc group and 17 patients in placebo groups completed the study. At baseline, there were no significant differences in any variable between the patients allocated to receive placebo and those taking zinc supplement. Zinc supplementation significantly reduced HDRS compared to placebo (P < 0.01 at 12th week). No significant differences were observed in plasma levels of IL-6, TNF-α, and BDNF-a between zinc-supplemented and placebo-supplemented group.ConclusionZinc supplementation in conjunction with antidepressant drugs might be beneficial for reducing depressive symptoms. However, its effect does not appear to be mediated through impact of zinc on inflammatory processes.

Effect of zinc supplementation on serum antibody titers to heat shock protein 27 in patients with thalassemia major

ObjectiveThis current study was conducted to determine the effect of zinc supplementation on antibody titers to heat shock protein 27 (anti-HSP27) in patients with beta-thalassemia major (β-TM).MethodsThis was a double-blinded placebo-controlled clinical trial conducted at Dr Sheikh Hospital (Mashhad, Iran) from 2011 to 2012. Sixty-four patients (41 females and 23 males), aged between 8 and 18 years with transfusion-dependent β-TM were randomly allocated to two age- and sex-matched groups. The zinc (case) group received 30 mg of daily zinc sulfate supplementation and the placebo (control) group received same shape and color placebo over 9 months period of the trial. Serum anti-HSP27 titers were measured at the third and ninth months of the trial, using an in-house enzyme-linked immune-absorbent assay.ResultThere was a significant difference in anti-HSP27 titers, between the groups after 9 months. The baseline value of anti-HSP27 was 0.44 ± 0.15 in zinc group and were significantly decreased to 0.40 ± 0.18 after 9 months on treatment, while the baseline value of anti-HSP27 were significantly increased from 0.43 ± 0.17 to 0.44 ± 0.18 in the placebo group (P = 0.01).ConclusionSerum anti-HSP27 titers were significantly reduced in patients with β-TM treated with zinc supplements compared to a group treated with a placebo. It suggests that the potential antioxidant and anti-inflammatory effects of zinc supplements may account for a reduction in anti-HSP27 titers in patients with β-TM.