Zinc Group Research Articles

Effects of acute exposure to aluminum on blood–brain barrier and the protection of zinc

Aluminum and zinc are two important trace elements in an organism. Although several studies have demonstrated their impacts on the intelligence, very little was known about their effects on the integrity of blood–brain barrier (BBB). To study the effects of aluminum and zinc on the permeability of BBB, different doses of aluminum and appropriate zinc were administered to rats. Evans blue was detected in brain to determine the permeability of BBB. The ultrastructure of BBB was observed under the transmission electron microscope. Immunohistochemistry and Western blot method were used to detect the expression of skeleton protein F-actin and tight junction protein occludin in brain capillary endothelium. The data indicated that compared with the control group, Evans blue in brains increased ( P < 0.01), the ultrastructure of BBB changed and the expression of F-actin and occludin decreased ( P < 0.01) in the aluminum-toxic group. Compared with the aluminum-toxic groups, the permeability of BBB to Evans blue decreased ( P < 0.01), the damage of the BBB ultrastructure was attenuated and the expression of F-actin and occludin increased ( P < 0.05) in the aluminum–zinc group. Our present studies suggest that aluminum increases the permeability of BBB by changing its ultrastructure and the expression of occludin and F-actin. Zinc can protect the integrity of BBB in juvenile rats that are exposed to aluminum and inhibit the decrease of tight junction protein occludin and F-actin expression in BBB.

Efficient encapsulation of a water-soluble corticosteroid in biodegradable nanoparticles

Solid nanoparticles consisting of biodegradable polymers have emerged as a promising carrier for various drugs, but unfortunately the encapsulation of drugs remains challenging. In this study, a technique for encapsulation of water-soluble drugs in solid nanoparticles was developed. Nanoparticles were prepared from a blend of biodegradable polymers, including poly(lactic acid) (PLA) and poly(lactic/glycolic acid) (PLGA), and monomethoxypolyethyleneglycol–polylactide block copolymer by an oil-in-water solvent diffusion method. Betamethasone sodium phosphate (BP) was not encapsulated by the nanoparticles due to its hydrophilicity, but it was effectively encapsulated in the presence of appropriate amounts of zinc and diethanolamine. It was found that BP formed an ionic complex with zinc at a certain pH range obtained by addition of diethanolamine. Furthermore, a carboxyl group located at the end of PLA/PLGA was shown to be essential for encapsulation of BP in nanoparticles, and the molar ratio among BP, zinc, and carboxyl groups in various nanoparticles was almost constant. These results strongly suggested that the encapsulation was promoted by zinc creating an ionic bridge between a carboxyl group on PLA/PLGA and a phosphate group on BP. This technique for entrapment of water-soluble drugs in solid biodegradable nanoparticles may expand the use of nanoparticles for various therapeutic applications.

004 Topical Zinc Oxide for Open Pilonidal Wounds

Extended healing time and lack of documented effective treatments of sacrococcygeal pilonidal disease create substantial problems. Locally applied zinc oxide has been reported to promote wound healing. We have compared topical zinc oxide (3%) with placebo meshes for pilonidal wounds healing by secondary intention in a randomized, double-blind, placebo-controlled multicenter trial. Sixty-four consecutive patients, 53 males, aged between 18 and 60 years (median 26 years) with excised pilonidal wounds were centrally randomized to local zinc oxide (30 mg/g, n = 33) or to placebo (n = 31) mesh treatment. Patients were followed with strict recording of beneficial and harmful effects. The median healing times were 54 days (42–71 days, interquartile range, n = 33) for the zinc group and 62 days (55–82 days, n = 31) for the placebo group. This difference was not statistically different (p = 0.32). Based on Cox regression analysis initial wound volume influenced healing negatively (p = 0.016) while smoking (p = 0.011) was associated with faster wound healing. Significantly (p < 0.01) more placebo (n = 12) than zinc oxide-treated patients (n = 3) needed antibiotics postoperatively. Although topical zinc oxide increased (p < 0.001) wound fluid zinc levels (1830 ± 405 μM, mean ± SEM) compared with placebo (3.1 ± 1.6 μM) serum-zinc levels did not differ significantly between the zinc (13.5 ± 0.4 μM) and placebo (12.8 ± 0.4 μm) groups on postoperative day 7. No adverse events were recorded. Topical zinc oxide treatment did not accelerate time to closure of open pilonidal wounds but was associated with reduced antibiotic usage.

Duration and Severity of Symptoms and Levels of Plasma Interleukin-1 Receptor Antagonist, Soluble Tumor Necrosis Factor Receptor, and Adhesion Molecules in Patients with Common Cold Treated with Zinc Acetate

Zinc lozenges have been used for treatment of the common cold; however, the results remain controversial. Fifty ambulatory volunteers were recruited within 24 h of developing symptoms of the common cold for a randomized, double-blind, placebo-controlled trial of zinc. Participants took 1 lozenge containing 13.3 mg of zinc (as zinc acetate) or placebo every 2-3 h while awake. The subjective scores for common cold symptoms were recorded daily. Plasma zinc, soluble interleukin (IL)-1 receptor antagonist (sIL-1ra), soluble tumor necrosis factor receptor 1, soluble vascular endothelial cell adhesion molecule, and soluble intercellular adhesion molecule (sICAM)-1 were assayed on days 1 and 5. Compared with the placebo group, the zinc group had a shorter mean overall duration of cold (4.0 vs. 7.1 days; P < .0001) and shorter durations of cough (2.1 vs. 5.0 days; P < .0001) and nasal discharge (3.0 vs. 4.5 days, P = .02) Blinding of subjects was adequate, and adverse effects were comparable in the 2 groups. Symptom severity scores were decreased significantly in the zinc group. Mean changes in plasma levels of zinc, sIL-1ra, and ICAM-1 differed significantly between groups. Administration of zinc lozenges was associated with reduced duration and severity of cold symptoms. We related the improvement in cold symptoms to the antioxidant and anti-inflammatory properties of zinc.

Blood cell, liver function, and response changes by PEG-interferon-α2b plus ribavirin with polaprezinc therapy in patients with chronic hepatitis C

Zinc has been reported to ameliorate hematologic side effects and improve liver function. In addition to its various effects, zinc supplementation in chronic hepatitis C patients with genotype 1b of high viral load enhanced the response to interferon (IFN) monotherapy. This study was aimed at clarifying whether zinc could improve hematologic side effects, improve liver function, and enhance the response to therapy in patients with chronic hepatitis C treated with pegylated-interferon (PEG-IFN) plus ribavirin (RBV). The 32 patients enrolled in the study were randomly divided into two groups: a PEG-IFN-alpha2b plus RBV with zinc group (PEG/RBV + zinc, n = 16) and a PEG-IFN-alpha2b plus RBV group (PEG/RBV, n = 16). HCV-RNA, serum zinc, ALT, white blood cell, red blood cell, platelet, and hemoglobin (Hb) levels were examined. Serum zinc levels were significantly higher in the PEG/RBV with zinc group than in the PEG/RBV without zinc group at 4, 8, and 12 weeks. No significant differences were observed in the clearance of HCV-RNA between the two groups. The outcome of the treatment was similar; results of laboratory examinations including ALT before, during, and after therapy revealed no significant differences between the two groups at any point in all items except serum zinc levels. A sustained virological response rate was observed in 50.0% in the PEG/RBV with zinc group and 43.8% in the PEG/RBV without zinc group, with no significant difference between the two groups. The study demonstrated no evidence that zinc ameliorates hematologic side effects, improves liver function, and enhances the response to the therapy in chronic hepatitis C receiving PEG-IFN-alpha2b plus RBV.

Zinc supplementation in children with cholera in Bangladesh: randomised controlled trial

Objective To investigate the impact of zinc supplementation in children with cholera.Design Double blind, randomised, placebo controlled trial.Setting Dhaka Hospital, Bangladesh.Participants 179 children aged 3-14 years with watery diarrhoea and...

Effect of Zinc Supplementation on Microalbuminuria in Patients With Type 2 Diabetes: A Double Blind, Randomized, Placebo-Controlled, Cross-Over Trial

Oxidative stress can contribute to microvascular complications in diabetes. A decisive event associated with this condition may be the decrease in the synthesis of zinc-containing antioxidant enzymes such as superoxide dismutase and glutathione peroxidase. This consideration led us to investigate the effect of zinc supplementation versus placebo on microalbuminuria in diabetic patients in a randomized double blind clinical trial. Fifty diabetic patients with microalbuminuria were enrolled. Fasting plasma glucose, HbA1c, lipid profiles, plasma zinc levels and random urine for albumin and creatinine were measured. Patients randomly received 30 mg elemental zinc (group 1) or placebo (group 2) for 3 months. After a 4 week wash-out period, the groups were crossed over (i.e. the zinc group were given placebo, and the placebo group were given zinc) and the protocol was repeated. From an initial number of 50 selected patients (25 in each of two groups), 39 patients (21 in group 1 and 18 in group 2) completed the study. In group 1, after zinc supplementation, urinary albumin excretion decreased significantly from 86.5 +/- 57 to 75 +/- 71 mg/g (p = 0.01). After placebo, patients in group 1 showed no significant reduction in microalbuminuria (85 +/- 72 mg/g to 83 +/- 63 mg/g creatinine). In group 2, no change in albumin excretion was observed after placebo treatment (90.5 +/- 63 mg/g to 90 +/- 60 mg/g creatinine). After zinc supplementation, a significant reduction was observed in albumin excretion, from 90 +/- 60 mg/g to 85 +/- 57 mg/g creatinine (p = 0.003). Zinc supplementation reduced albumin excretion in microalbuminuric type 2diabetic patients. This outcome may be due to the antioxidant effect of zinc.

Potential effects of zinc on information processing in boys with attention deficit hyperactivity disorder

Purpose The aims of the present study were to investigate the relationship between plasma zinc levels and amplitudes and latencies of P1, N2, and P3 in parietal and frontal areas in children with ADHD, and to compare these zinc levels and event-related potentials (ERPs) indices with controls. Methods 28 boys with ADHD were divided into two groups according to plasma zinc levels: low zinc group ( N = 13, zinc level < 80 μg/dL) and zinc non-deficient group ( N = 15, zinc level ≥ 80 μg/dL). ERP indices from parietal and frontal brain regions were recorded in children with ADHD and in 24 normal boys by using an auditory oddball paradigm. Plasma zinc levels were measured by an atomic absorption spectrophotometer. Results The plasma zinc levels were significantly lower in both ADHD groups (means are 65.8 μg/dL in low zinc group and 89.5 μg/dL in zinc non-deficient group) than controls (mean: 107.8 μg/dL; both p values < 0.017). In ADHD compared to controls, the amplitudes of P3 in frontal and parietal regions were significantly lower, and the latency of P3 in parietal region was significantly longer (all p values < 0.017). In low zinc ADHD group compared to zinc non-deficient ADHD group, the latencies of N2 in frontal and parietal region were significantly shorter (all p values < 0.017). In addition, there was a medium but significant positive correlation between plasma zinc levels and amplitude and latency of frontal N2 wave in ADHD. Conclusions These results can suggest that plasma zinc levels might have an effect on information processing in ADHD children, and lower zinc levels seem to affect N2 wave. Since N2 wave changes may reflect a different inhibition process, further studies are warranted to investigate the effect of zinc on inhibitory process in children with ADHD, and in low zinc and non-deficient ADHD groups.

Zinc Deficiency Alters Lipid Metabolism in LDL Receptor–Deficient Mice Treated with Rosiglitazone

Zinc is a structural and functional component of PPAR and zinc deficiency may be associated with an increased risk for cardiovascular diseases. We tested the hypothesis that zinc deficiency compromises lipid metabolism in rosiglitazone (RSG)-treated mice lacking the LDL-receptor (LDL-R) gene. LDL-R-deficient mice were maintained for 3 wk on low-fat (7 g/100 g) diets that were either zinc deficient or zinc adequate. Subsequently, diets were adjusted to a high-fat (HF) (15 g/100 g) regimen for 1 wk to produce a biological environment of mild oxidative and inflammatory stress. One-half of the mice within each zinc group was gavaged daily with the PPARγ agonist RSG starting 2 d prior to the HF feeding. Selected lipid parameters were studied. Zinc deficiency increased plasma total cholesterol, which was also elevated by RSG. Zinc deficiency also caused an increased lipoprotein-cholesterol distribution toward the non-HDL fraction (VLDL, intermediate density lipoprotein, LDL). Plasma total fatty acids tended to increase during zinc deficiency and RSG treatment resulted in similar changes in the fatty acid profile in zinc-deficient mice. Fatty acid translocase (FAT/CD36) expression in abdominal aorta was upregulated by RSG only in zinc-deficient mice. In contrast, RSG treatment markedly increased lipoprotein lipase (LPL) expression only in zinc-adequate mice. In vitro studies confirmed that adequate zinc is required for RSG-induced PPARγ activity to transactivate target genes. These data suggest that in this atherogenic mouse model treated with RSG, lipid metabolism can be compromised during zinc deficiency and that adequate dietary zinc may be considered during therapy with the antidiabetic medicine RSG.

Effect of zinc sulfate on common cold in children: Randomized, double blind study

The aim of the present randomized, double-blind, placebo-controlled study was to determine the efficacy of zinc sulfate on the duration and severity of common cold in children. Children presenting at least two of 10 symptoms of common cold within the 24-48 h of the onset of illness were eligible for the study. Children were randomized to receive either oral zinc containing zinc sulfate or placebo. A diary was completed to record symptoms and adverse effects. Symptoms were scored as absent (0), mild (1), moderate (2), or severe (3). One hundred and fifty children participated in the study, and 120 children were included in the final analysis. The median duration of all cold symptoms was 6 days (P = 0.20), and the median duration of nasal symptoms was 5 days in both groups (P = 0.09). However, total symptom severity scores were significantly lower in the zinc group, starting from the second day of the study. The lower scores in the zinc group were largely due to improvement of nasal symptom scores. Adverse effects were similar in both groups. Zinc sulfate had no effect on the duration of cold symptoms. However, it appears to be effective in reducing the severity of the cold symptoms in healthy children.

Effect of Vitamin A and Zinc Supplementation on Gastrointestinal Parasitic Infections Among Mexican Children

Gastrointestinal parasites continue to be an important cause of morbidity and stunting among children in developing countries. We evaluated the effect of vitamin A and zinc supplementation on infections by Giardia lamblia, Ascaris lumbricoides, and Entamoeba histolytica. A randomized, double-blind, placebo-controlled trial was conducted among 707 children who were 6 to 15 months of age and from periurban areas of Mexico City, Mexico, between January 2000 and May 2002. Children, who were assigned to receive either vitamin A every 2 months, a daily zinc supplement, a combined vitamin A and zinc supplement, or a placebo, were followed for 1 year. The primary end points were the 12-month rates and durations of infection for the 3 parasites and rates of parasite-associated diarrheal disease as determined in stools collected once a month and after diarrheal episodes. G. lamblia infections were reduced and A. lumbricoides infections increased among children in the combined vitamin A and zinc group or the zinc alone group, respectively. Durations of Giardia infections were reduced among children in all 3 treatment arms, whereas Ascaris infections were reduced in the vitamin A and zinc group. In contrast, E. histolytica infection durations were longer among zinc-supplemented children. Finally, E. histolytica- and A. lumbricoides-associated diarrheal episodes were reduced among children who received zinc alone or a combined vitamin A and zinc supplement, respectively. We found that vitamin A and zinc supplementation was associated with distinct parasite-specific health outcomes. Vitamin A plus zinc reduces G. lamblia incidence, whereas zinc supplementation increases A. lumbricoides incidence but decreases E. histolytica-associated diarrhea.

Effect of daily zinc supplementation on child mortality in southern Nepal: a community-based, cluster randomised, placebo-controlled trial

Zinc supplementation can reduce subsequent morbidity in children recovering from diarrhoea and respiratory illness in developing countries. However, whether routine supplementation would decrease morbidity and mortality in populations with zinc deficiency is unclear. We assessed the effect of daily zinc supplementation on children in southern Nepal. We did a community-based, cluster-randomised, double-masked, placebo-controlled, 2x2 factorial trial in children aged 1-35 months. Treatment groups were placebo, iron and folic acid, zinc, and iron and folic acid with zinc, with daily doses of 12.5 mg iron, 50 microg folic acid, and 10 mg zinc. Study staff gave children tablets on 2 days each week and left tablets with caregivers for other days. All children received vitamin A supplementation twice per year. Results of the iron arm of the trial have been reported previously. Between October, 2001, and January, 2006, 41,276 children were enrolled into the placebo (n=20,308) or zinc (n=20,968) groups and were followed-up for 60,636.3 person-years. The primary outcome was child mortality, and analyses were by intention to treat. Daily reports of signs and symptoms of common morbidities in stratified random subsamples of children were assessed every week for 12 months. This study is registered at ClinicalTrials.gov, number NCT00109551. 2505 children refused to continue the trial and 3219 children were lost to follow-up. There was no significant difference in mortality between the zinc and placebo groups (316 vs 333 deaths; hazard ratio 0.92, 95% CI 0.75-1.12). Zinc had no effect on mortality in children younger than 12 months (181 vs 168 deaths; 1.04, 0.83-1.31); mortality was lower, but not statistically significantly so, in older children receiving zinc (135 vs 165; 0.80, 0.60-1.06). The frequency and duration of diarrhoea, persistent diarrhoea, dysentery, and acute lower respiratory infections did not differ between the groups. Total mortality of children receiving zinc supplementation was not significantly different from that of children receiving placebo. Further data are needed from other populations with endemic zinc deficiency to confirm the potential age-specific effects reported in this study.

Zinc or Multiple Micronutrient Supplementation to Reduce Diarrhea and Respiratory Disease in South African Children: A Randomized Controlled Trial

BackgroundProphylactic zinc supplementation has been shown to reduce diarrhea and respiratory illness in children in many developing countries, but its efficacy in children in Africa is uncertain.ObjectiveTo determine if zinc, or zinc plus multiple micronutrients, reduces diarrhea and respiratory disease prevalence.DesignRandomized, double-blind, controlled trial.SettingRural community in South Africa.ParticipantsThree cohorts: 32 HIV-infected children; 154 HIV-uninfected children born to HIV-infected mothers; and 187 HIV-uninfected children born to HIV-uninfected mothers.InterventionsChildren received either 1250 IU of vitamin A; vitamin A and 10 mg of zinc; or vitamin A, zinc, vitamins B1, B2, B6, B12, C, D, E, and K and copper, iodine, iron, and niacin starting at 6 months and continuing to 24 months of age. Homes were visited weekly.Outcome MeasuresPrimary outcome was percentage of days of diarrhea per child by study arm within each of the three cohorts. Secondary outcomes were prevalence of upper respiratory symptoms and percentage of children who ever had pneumonia by maternal report, or confirmed by the field worker.ResultsAmong HIV-uninfected children born to HIV-infected mothers, median percentage of days with diarrhea was 2.3% for 49 children allocated to vitamin A; 2.5% in 47 children allocated to receive vitamin A and zinc; and 2.2% for 46 children allocated to multiple micronutrients (P = 0.852). Among HIV-uninfected children born to HIV-uninfected mothers, median percentage of days of diarrhea was 2.4% in 56 children in the vitamin A group; 1.8% in 57 children in the vitamin A and zinc group; and 2.7% in 52 children in the multiple micronutrient group (P = 0.857). Only 32 HIV-infected children were enrolled, and there were no differences between treatment arms in the prevalence of diarrhea. The prevalence of upper respiratory symptoms or incidence of pneumonia did not differ by treatment arms in any of the cohorts.ConclusionWhen compared with vitamin A alone, supplementation with zinc, or with zinc and multiple micronutrients, did not reduce diarrhea and respiratory morbidity in rural South African children.Trial RegistrationClinicalTrials.gov NCT00156832

Lead Does Not Affect Transcription of Intestinal Zinc-Binding Proteins in Growing Rats:

Environmental lead exposure remains a serious concern for the growth and development of children. Micronutrient status may affect the absorption and tissue accumulation of lead, but the mechanisms of gastrointestinal uptake and transport remain unknown. Thus, our objective was to investigate the effects of lead on the mRNA levels of intestinal zinc transporter 4 (ZIP4), metallothionein (MT), cysteine-rich intestinal protein (CRIP), and divalent metal transporter 1 (DMT1) in growing rats fed marginal, adequate, and supplemental zinc diets. Weanling Sprague Dawley rats were assigned to marginal zinc (MZ; 8 mg Zn/kg diet), zinc-adequate control (CT; 30 mg Zn/kg), zinc-adequate diet-restricted (DR; 30 mg Zn/kg), or supplemental zinc (SZ; 300 mg Zn/kg) groups, with and without lead acetate-containing drinking water (200 mg Pb/l) for 3 weeks. Duodenum was analyzed for ZIP4, MT, CRIP, and DMT1 mRNA levels by real-time reverse transcription-polymerase chain reaction and MT immunolocalization. Tissues were analyzed for zinc, lead, and iron by inductively coupled plasma spectrometry. MZ rats had higher duodenal ZIP4 mRNA levels, lower MT mRNA levels, lower MT immunostaining intensity, and lower zinc concentrations than DR, CT, and SZ. Duodenal DMT1 mRNA levels were lower in DR and SZ compared with MZ. Tissue lead concentrations responded to dietary zinc with SZ < CT < DR <or= MZ. The greater accumulation of hepatic lead in MZ rats was associated with zinc deficiency as well as diet restriction. Lead treatment resulted in higher hepatic iron concentrations but had no effect on duodenal ZIP4, MT, CRIP, or DMT1 mRNA levels. Thus, tissue lead accumulation was not directly mediated by the transcriptional induction of zinc and iron binding or transport proteins. The mechanisms of lead absorption during nutritional deficiency and supplementation require further investigation.

Consumption of a moderately Zn-deficient and Zn-supplemented diet affects soluble protein expression in rat soleus muscle

Zinc deficiency negatively affects muscle function, but there are limited biochemical data identifying the cause of this reduction in function. The objective of the present study was to identify soluble proteins in rat soleus muscle that were responsive to different levels of dietary zinc. Rats ( n=21) were fed diets containing three concentrations of zinc: 5, 30 and 200 ppm for 42 days. There was no difference in body weights of the rats consuming the 5-ppm zinc diet compared to the rats consuming the 30- or 200-ppm zinc diets; however, bone zinc levels were significantly decreased in the 5-ppm dietary zinc group. Individual soluble protein fractions were isolated from these muscles and the samples were prepared for two-dimensional polyacrylamide gel electrophoresis. The expression levels of four proteins were significantly depressed by dietary Zn depletion and supplementation, S-glutathiolated carbonic anhydrase, myosin light polypeptide 3, heat shock protein 20 and heart fatty acid binding protein. This is the first report that indicates that both Zn depletion and supplementation result in protein expression profiles that may negatively affect skeletal muscle function. These results indicate that there are specific signaling pathways that require proper Zn nutriture for maintaining optimal muscle function and suggest that the consumption of pharmacologic doses of Zn may be detrimental to muscle function.

Operational Feasibility of Implementing Community-Based Zinc Supplementation

To determine the effect of zinc supplementation on diarrheal incidence and to discover any operational constraints of zinc supplementation at the community level. We included 1712 children aged between 6 and 48 months in a randomized double blind study in rural area comprising of 11 villages. Children were randomly divided into 2 groups. Zinc/placebo syrup supplementation was continued for 6 months in a weekly schedule from May 2003. Children were followed up weekly for detection of diarrhea from May 2003 until April 2004. Around 30% of the study children were evaluated every 2 months during supplementation period. During the period, 80,534 weekly visits were made giving 1548.73-child years of observation. We detected 1438 diarrheal episodes among 846 children. The incidence of diarrhea was significantly less during the supplemented period (P < 0.001; RR 0.74 (0.64-0.87)) in the zinc group. A significant difference was also noted during the follow up period (P < 0.05). In the zinc group, children <2 years of age had significantly less diarrhea during supplementation and the follow up period. Multiple episodes of diarrhea (>or=2) were significantly less in the zinc group. Approximately 85% of the surveillance workers made weekly visits to the houses and 96% of mothers administered syrup weekly to their children. Around 80% of mother's were aware of the possible benefits of zinc supplementation. Weekly zinc supplementation was effective in reducing diarrheal morbidity at the community level and it was operationally feasible.

Topical zinc oxide vs. salicylic acid–lactic acid combination in the treatment of warts

Warts are a common dermatologic problem. Treatment is painful, prolonged, and can cause scarring. To evaluate topical zinc oxide for the treatment of warts. This was a randomized, double-blind controlled trial of 44 patients. Twenty-two patients were given topical zinc oxide 20% ointment, and the other 22 received salicylic acid 15% + lactic acid 15% ointment twice daily. All patients were followed up for 3 months or until cure, whichever occurred first. All patients were observed for side-effects. Sixteen patients in the zinc group and 19 in the salicylic acid-lactic acid group completed the study. In the zinc oxide-treated group, 50% of the patients showed complete cure and 18.7% failed to respond, compared with 42% and 26%, respectively, in the salicylic acid-lactic acid-treated group. No patients developed serious side-effects. Topical zinc oxide is an efficacious, painless, and safe therapeutic option for wart treatment.

Impact of zinc supplementation on subsequent morbidity and growth in Bangladeshi children with persistent diarrhoea.

This study was conducted to explore whether supplementation of zinc to children during persistent diarrhoea has any subsequent effect on morbidity and growth. A prospective follow-up study was conducted among children, aged 3-24 months, with persistent diarrhoea, who participated earlier in a double-blind randomized placebo-controlled trial. During persistent diarrhoea, children were randomly allocated to receive either zinc in multivitamin syrup or only multivitamin syrup for two weeks. After recovering from diarrhoea, 76 children in the multi-vitamin syrup and 78 children in the zinc plus multivitamin syrup group were followed up for subsequent morbidity and growth. Weekly morbidity and two-weekly anthropometric data were collected for the subsequent 12 weeks. Data showed that episodes and duration of diarrhoea were reduced by 38% and 44% respectively with supplementation of zinc. There was no significant difference in the incidence or duration of respiratory tract infection between the zinc-supplemented and the non-supplemented group. Improved linear growth was observed in underweight children (weight-for-age <70% of the National Center for Health Statistics standard) who received zinc compared to those who did not receive.

Mild zinc deficiency and dietary phytic acid accelerates the development of fulminant hepatitis in LEC rats

Restriction of copper intake delays hepatic copper accumulation in Long-Evans Cinnamon (LEC) rats, which are animal models of Wilson's disease. Involvement of zinc is suggested to develop hepatitis in the disease; however, this has not been clarified. The aims of this study were to investigate the effects of mild zinc deficiency on the development of hepatitis and to determine the relationship between the absorption and hepatic levels of copper, zinc and iron. Male LEC and F344 (wild type atp7b) rats were fed a low zinc, phytate-containing or control diet. The onset of hepatitis (Experiment 1), and absorptive rates of copper, zinc and iron and hepatitis indices in 4 weeks (Experiment 2) were observed. The onset of fulminant hepatitis in LEC rats was much earlier in the low zinc and phytate groups (mean 94.6 +/- 2.74 days and 82.8 +/- 3.56 days old, respectively) than in the control group (136 +/- 2.11 days old) with worse hepatitis indices. Hepatic copper levels were much higher in LEC rats than F344 rats, but were not largely different among the diet groups without prominent changes in copper absorption. Hepatic levels and intestinal absorption of zinc and iron were lower in the phytate group than in the control group. Mild zinc deficiencies caused by a low zinc or phytate-containing diet accelerate the onset of hepatitis in LEC rats without increasing copper absorption, and zinc and iron metabolism may be involved in the earlier onset of jaundice of LEC rats.

Immunization with the heptavalent pneumococcal conjugate vaccine in Bangladeshi infants and effects of zinc supplementation

Background Zinc deficiency is known to impair immunologic functions. However, the effect of zinc supplementation on immune response to polysaccharide vaccines is not known. Objective To determine the immunogenicity of the heptavalent Pneumococcal protein conjugate (PNC) vaccine in poor Bangladeshi infants and to assess the effect of zinc supplementation on immune response to the PNC vaccine. Design We immunized a sub-cohort of 241 infants who had previously received three doses of a Hib conjugate vaccine with three doses of the heptavalent PNC vaccine at 4 weeks intervals beginning at 18 ± 1 weeks of age. The infants were supplemented with daily 5 mg zinc or placebo from 4 to 33 weeks of age. Response to each of the seven PNC serotypes were assessed at 4, 24 and 33 weeks of age. Results After three doses of PNC, at 29 weeks of age, geometric mean titres for the pneumococcal serotypes ranged from 3.68 to 13.34 μg/ml. Titres were significantly higher for infants who had received PNC compared to infants who had only received DTP-Hib. Zinc supplementation resulted in higher titres for serotype 9V (4.09 μg/ml; [95% CI: 3.27; 5.10] and 3.33 μg/ml; [95% CI: 2.79; 3.96] for zinc and placebo group, respectively; p < 0.05) after three doses but had no effect on other serotypes. Conclusions A heptavalent PNC vaccine proved to be safe and immunogenic in Bangladeshi infants. Zinc supplementation enhanced the immune response to only one of the serotypes (9V). However, there was no effect on other serotypes.