Clinical and laboratory assessment of zinc deficiency in Dutch children. A review

Atopic Dermatitis-like Genodermatosis: Disease Diagnosis and Management

Eczema is a classical characteristic not only in atopic dermatitis but also in various genodermatosis. Patients suffering from primary immunodeficiency diseases such as hyper-immunoglobulin E syndromes, Wiskott-Aldrich syndrome, immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, STAT5B deficiency, Omenn syndrome, atypical complete DiGeorge syndrome; metabolic disorders such as acrodermatitis enteropathy, multiple carboxylase deficiency, prolidase deficiency; and other rare syndromes like severe dermatitis, multiple allergies and metabolic wasting syndrome, Netherton syndrome, and peeling skin syndrome frequently perform with eczema-like lesions. These genodermatosis may be misguided in the context of eczematous phenotype. Misdiagnosis of severe disorders unavoidably affects appropriate treatment and leads to irreversible outcomes for patients, which underlines the importance of molecular diagnosis and genetic analysis. Here we conclude clinical manifestations, molecular mechanism, diagnosis and management of several eczema-related genodermatosis and provide accessible advice to physicians.

Blood Levels of Ammonia and Carnitine in Patients Treated with Valproic Acid: A Meta-analysis

Objective

Long-term valproic acid (VPA) administration is associated with adverse metabolic effects, including hyperammonemia and hypocarnitinemia. However, the pathogeneses of these adverse events remain unclear, and not enough reviews have been performed. The aim of this study was to conduct a meta-analysis of studies examining blood levels of ammonia and carnitine in patients treated with VPA.

Methods

We conducted database searches (PubMed, Web of Science) to identify studies examining blood levels of ammonia and carnitine in patients treated with VPA. A meta-analysis was performed to conduct pre- and post-VPA treatment comparisons, cross-sectional comparisons between groups with and without VPA use, and estimations of the standardized correlations between blood levels of ammonia, carnitine, and VPA.

Results

According to the cross-sectional comparisons, the blood ammonia level in the VPA group was significantly higher than that in the non-VPA group. Compared to that in the non-VPA group, the blood carnitine level in the VPA group was significantly lower. In the meta-analysis of correlation coefficients, the blood VPA level was moderately correlated with blood ammonia and blood free carnitine levels in the random effects model. Furthermore, the blood ammonia level was moderately correlated with the blood free carnitine level.

Conclusion

Although the correlation between ammonia and free carnitine levels in blood was significant, the moderate strength of the correlation does not allow clinicians to infer free carnitine levels from the results of ammonia levels. Clinicians should measure both blood ammonia and free carnitine levels, especially in patients receiving high dosages of VPA.

International consensus statement on allergy and rhinology: Olfaction

BACKGROUND

The literature regarding clinical olfaction, olfactory loss, and olfactory dysfunction has expanded rapidly over the past two decades, with an exponential rise in the past year. There is substantial variability in the quality of this literature and a need to consolidate and critically review the evidence. It is with that aim that we have gathered experts from around the world to produce this International Consensus on Allergy and Rhinology: Olfaction (ICAR:O).

METHODS

Using previously described methodology, specific topics were developed relating to olfaction. Each topic was assigned a literature review, evidence-based review, or evidence-based review with recommendations format as dictated by available evidence and scope within the ICAR:O document. Following iterative reviews of each topic, the ICAR:O document was integrated and reviewed by all authors for final consensus.

RESULTS

The ICAR:O document reviews nearly 100 separate topics within the realm of olfaction, including diagnosis, epidemiology, disease burden, diagnosis, testing, etiology, treatment, and associated pathologies.

CONCLUSION

This critical review of the existing clinical olfaction literature provides much needed insight and clarity into the evaluation, diagnosis, and treatment of patients with olfactory dysfunction, while also clearly delineating gaps in our knowledge and evidence base that we should investigate further.

Embryonic Hypotaurine Levels Contribute to Strain-Dependent Susceptibility in Mouse Models of Valproate-Induced Neural Tube Defects

Valproic acid (VPA, valproate, Depakote) is a commonly used anti-seizure medication (ASM) in the treatment of epilepsy and a variety of other neurological disorders. While VPA and other ASMs are efficacious for management of seizures, they also increase the risk for adverse pregnancy outcomes, including neural tube defects (NTDs). Thus, the utility of these drugs during pregnancy and in women of childbearing potential presents a continuing public health challenge. Elucidating the underlying genetic or metabolic risk factors for VPA-affected pregnancies may lead to development of non-teratogenic ASMs, novel prevention strategies, or more targeted methods for managing epileptic pregnancies. To address this challenge, we performed unbiased, whole embryo metabolomic screening of E8.5 mouse embryos from two inbred strains with differential susceptibility to VPA-induced NTDs. We identified metabolites of differential abundance between the two strains, both in response to VPA exposure and in the vehicle controls. Notable enriched pathways included lipid metabolism, carnitine metabolism, and several amino acid pathways, especially cysteine and methionine metabolism. There also was increased abundance of ω-oxidation products of VPA in the more NTD-sensitive strain, suggesting differential metabolism of the drug. Finally, we found significantly reduced levels of hypotaurine in the susceptible strain regardless of VPA status. Based on this information, we hypothesized that maternal supplementation with L-carnitine (400 mg/kg), coenzyme A (200 mg/kg), or hypotaurine (350 mg/kg) would reduce VPA-induced NTDs in the sensitive strain and found that administration of hypotaurine prior to VPA exposure significantly reduced the occurrence of NTDs by close to one-third compared to controls. L-carnitine and coenzyme A reduced resorption rates but did not significantly reduce NTD risk in the sensitive strain. These results suggest that genetic variants or environmental exposures influencing embryonic hypotaurine status may be factors in determining risk for adverse pregnancy outcomes when managing the health care needs of pregnant women exposed to VPA or other ASMs.

Case report: Acrodermatitis enteropathica result from a novel SLC39A4 gene mutation

The clinical data and gene sequencing results in a child with acrodermatitis enteropathica were retrospectively reported, and the related literature was reviewed. A girl aged 9 years and 4 months presented with a repeated skin rash, mainly distributed in the perioral, anogenital, and acral areas, accompanied with alopecia, and a low blood zinc level was found many times. A significant improvement was seen after continuous zinc supplementation. The genetic sequencing test demonstrated that the patient had compound heterozygous for two SLC39A4 mutations: c.1466dupT (p.S490Efs*155) and c.295G > A (p.A99T), and her parents were heterozygous carriers of these two mutations. An improvement was achieved after continuous zinc supplementation. This case report might guide further research on this aspect.

Enhancing effect of Panax ginseng on Zip4-mediated zinc influx into the cytosol

Background

Zinc homeostasis is essential for human health and is regulated by several zinc transporters including ZIP and ZnT. ZIP4 is expressed in the small intestine and is important for zinc absorption from the diet. We investigated in the present study the effects of Panax ginseng (P. ginseng) extract on modulating Zip4 expression and cellular zinc levels in mouse Hepa cells.

Methods

Hepa cells were transfected with a luciferase reporter plasmid that contains metal-responsive elements, incubated with P. ginseng extract, and luciferase activity was measured. Using ⁶⁵ZnCl₂, zinc uptake in P. ginseng-treated cells was measured. The expression of Zip4 mRNA and protein in Hepa cells was also investigated. Finally, using a luciferase reporter assay system, the effects of several ginsenosides were monitored.

Results

The luciferase activity in cells incubated with P. ginseng extract was significantly higher than that of control cells cultured in normal medium. Hepa cells treated with P. ginseng extract exhibited higher zinc uptake. P. ginseng extract induced Zip4 mRNA expression, which resulted in an enhancement of Zip4 protein expression. Furthermore, some ginsenosides, such as ginsenoside Rc and Re, enhanced luciferase activity driven by intracellular zinc levels.

Conclusion

P. ginseng extract induced Zip4 expression at the mRNA and protein level and resulted in higher zinc uptake in Hepa cells. Some ginsenosides facilitated zinc influx. On the basis of these results, we suggest a novel effect of P. ginseng on Zip4-mediated zinc influx, which may provide a new strategy for preventing zinc deficiency.

Zinc and skin biology

Of all tissues, the skin has the third highest abundance of zinc in the body. In the skin, the zinc concentration is higher in the epidermis than in the dermis, owing to a zinc requirement for the active proliferation and differentiation of epidermal keratinocytes. Here we review the dynamics and functions of zinc in the skin as well as skin disorders associated with zinc deficiency, zinc finger domain-containing proteins, and zinc transporters. Among skin disorders associated with zinc deficiency, acrodermatitis enteropathica is a disorder caused by mutations in the ZIP4 transporter and subsequent zinc deficiency. The triad acrodermatitis enteropathica is characterized by alopecia, diarrhea, and skin lesions in acral, periorificial, and anogenital areas. We highlight the underlying mechanism of the development of acrodermatitis because of zinc deficiency by describing our new findings. We also discuss the accumulating evidence on zinc deficiency in alopecia and necrolytic migratory erythema, which is typically associated with glucagonomas.

Acrodermatitis Enteropathica: A Case Report

Acrodermatitis enteropathica is a rare genetic autosomal recessive disorder, characterized by periorificial dermatitis, alopecia, and diarrhea. It is caused by mutations in the gene that encodes a membrane protein that binds zinc. We report a 14-month-old boy, admitted for erythematous, scaly and pustular lesions, initially located in the inguinal and perianal regions and on thighs, and very few erythematous lesions on the face. Due to the numerous bacterial skin superinfections with Staphylococcus aureus, including abscesses that required surgical incision, the clinical picture was modified, leading to a delayed establishment of the diagnosis. Later, the symptoms became suggestive for this disease, the diagnostic having been confirmed by low plasma zinc values. Under zinc therapy, skin lesions improved significantly in a few days, with favorable outcome. Two months later, the skin lesions almost disappeared.Abscesses due to bacterial skin superinfections may lead to initially misdiagnosed acrodermatitis enteropathica.

Genetic causes and gene–nutrient interactions in mammalian zinc deficiencies: acrodermatitis enteropathica and transient neonatal zinc deficiency as examples

Discovering genetic causes of zinc deficiency has been a remarkable scientific journey. It started with the description of a rare skin disease, its treatment with various agents, the successful therapy with zinc, and the identification of mutations in a zinc transporter causing the disease. The journey continues with defining the molecular and cellular pathways that lead to the symptoms caused by zinc deficiency. Remarkably, at least two zinc transporters from separate protein families are now known to be involved in the genetics of zinc deficiency. One is ZIP4, which is involved in intestinal zinc uptake. Its mutations can cause acrodermatitis enteropathica (AE) with autosomal recessive inheritance. The other one is ZnT2, the transporter responsible for supplying human milk with zinc. Mutations in this transporter cause transient neonatal zinc deficiency (TNZD) with symptoms similar to AE but with autosomal dominant inheritance. The two diseases can be distinguished in affected infants. AE is fatal if zinc is not supplied to the infant after weaning, whereas TNZD is a genetic defect of the mother limiting the supply of zinc in the milk, and therefore the infant usually will obtain enough zinc once weaned. Although these diseases are relatively rare, the full functional consequences of the numerous mutations in ZIP4 and ZnT2 and their interactions with dietary zinc are not known. In particular, it remains unexplored whether some mutations cause milder disease phenotypes or increase the risk for other diseases if dietary zinc requirements are not met or exceeded. Thus, it is not known whether widespread zinc deficiency in human populations is based primarily on a nutritional deficiency or determined by genetic factors as well. This consideration becomes even more significant with regard to mutations in the other 22 human zinc transporters, where associations with a range of diseases, including diabetes, heart disease, and mental illnesses have been observed. Therefore, clinical tests for genetic disorders of zinc metabolism need to be developed.

Estimated daily intake of Fe, Cu, Ca and Zn through common cereals in Tehran, Iran

This paper presents the findings of study undertaken to estimate the dietary intake of iron (Fe), copper (Cu), calcium (Ca) and zinc (Zn) through common cereals in Tehran, Iran. 100 samples of rice, wheat and barley were collected from various brands between August and October 2013. The samples were analyzed performing instrumental neutron activation analysis (INAA). The dietary intake for adults was estimated by a total cereal study. Calculations were carried out on the basis of the reported adults' average food consumption rate data. The total daily intake estimated in mgd(-1) for Tehran population were 3.6 (Fe), 10.2 (Zn), 0.3 (Cu) and 234.5 (Ca). Wheat showed the highest contribution to Zn, Cu and Ca intakes. Furthermore, intakes were compared with recommended dietary allowance (RDA). Zn total intake (10.2mgd(-1)) was comparable with RDA values for males (11mgd(-1)) and was higher than recommended value for females (8mgd(-1)). The intakes of other studied elements were below the respective RDAs.

Comparison of salty taste acuity and salty taste preference with sodium intake and blood pressure based on zinc nutritional status in two rural populations in Korea

This study examined salty taste acuity and salty taste preference and sodium intake in relation to zinc nutritional status in 2 rural populations in Korea. And we also examined the main food contributors of their sodium intakes. We enrolled 218 adults (66 men and 152 women) from the Kangneung and Samcheok regions in Korea's Kangwon province in our study conducted from December 2011 to February 2012. Participants from each region were divided into 3 groups based on their serum zinc level (T1: lowest, T2: intermediate, T3: highest). We compared the salty taste acuity and preference, Na index (Dish Frequency Questionnaire for estimation of habitual sodium intake), blood pressure, and intakes of nutrients including sodium by 3 groups of serum zinc level. The results were as follows: a higher serum zinc level indicated a lower sodium intake and Na index (P < 0.05). The salty taste acuity was considerably higher for participants from the Kangneung region than those from the Samcheok region (P < 0.05). And the serum zinc level was significantly higher in participants from the Kangneung region than those from the Samcheok region (P < 0.05). We further divided the participants into 2 groups: those who consumed more zinc than the recommended intake (RI) and the others. We compared salty taste acuity and salty taste preference in the 2 groups. The salty taste threshold and palatable salty taste concentrations were lower for the group with a zinc intake above RI than for the group with zinc intake below the RI. However, the difference was not significant. This study confirms that taste function differs depending on zinc nutritional status. In future, it is required to a large-scale, long-term, prospective study on the correlation between zinc intake, serum zinc levels, and taste perception function and blood pressure.

Acquired acrodermatitis enteropathica due to zinc deficiency in a patient with pre-existing Darier's disease

BACKGROUND

Acrodermatitis enteropathica is characterised by inflamed patches of dry red skin which then become crusted and blistered before revealing a pustulent eroded lesion. Typically these patches start near the body's orifices before migrating to other sites, however in this patient the presentation was atypical thus delaying the diagnosis.

OBSERVATIONS

We report a case of an atypical presentation of acrodermatitis enteropathica (AE) due to acquired zinc deficiency in a 65 year old female patient with a previous diagnosis of histologically confirmed Darier's disease. This patient's rash began on the limbs and trunk before progressing to include the perineum, oral mucosa and nose. Diffuse loss of hair on scalp, eyebrows and eyelashes was observed. Acrodermatitis enteropathica typically presents in infants, either due to an autosomal recessive genetic disorder, or after the cessation of breast feeding. In adults acquired zinc deficiency can be caused by glucagonoma syndrome, poor nutritional state, intestinal malabsorption, nephrotic syndrome and after major trauma (i.e. burns or significant surgery). In our patient low zinc levels confirmed hypozincaemia and the diagnosis of acrodermatitis enteropathica. The patient started oral zinc replacement. Within a few days her symptoms began to improve, and her hair has started to grow.

CONCLUSION

We believe this to be an unusual presentation of acrodermatitis enteropathica due to a probable dietary zinc deficiency in a lady with pre-existing Darier's disease which may possibly have influenced the uncharacteristic clinical presentation.

A Zinc Sulphate-Resistant Acrodermatitis Enteropathica Patient with a Novel Mutation in SLC39A4 Gene

Acrodermatitis enteropathica (AE) is a rare autosomal recessive disorder of zinc deficiency due to an abnormal intestinal zinc transporter. It is characterized by the triad of acral dermatitis, alopecia, and diarrhoea. Once AE is correctly diagnosed, patients are treated with orally administered zinc sulphate. In some patients, relapses occur during adolescence, despite the regular treatment. Here, we discuss the clinical and molecular features of a 13-year-old adolescent girl with acrodermatitis enteropathica who was resistant to high-dose zinc sulphate therapy. We successfully treated the patient with zinc gluconate and vitamin C, and we detected a novel homozygous c.541_551dup (p.Leu186fsX38) mutation in the exon 3 of her SLC39A4 gene.

Congenital zinc deficiency from mutations of the SLC39A4 gene as the genetic background of acrodermatitis enteropathica

Acrodermatitis enteropathica (AE) is an autosomal recessive disorder with the clinical triad of acral dermatitis, diarrhea and alopecia. AE is known to be caused by mutations of the SLC39A4 gene on the chromosome band 8q24.3, encoding the zinc transporter in human. An 8-month-old Korean boy presented with eczematous changes on the inguinal area and knees and was diagnosed with AE. Blood tests revealed a markedly decreased level of plasma zinc, and his symptoms improved on oral zinc replacement. To confirm the diagnosis of AE from congenital zinc deficiency, direct sequencing analysis of SLC39A4 was performed and revealed that he was compound heterozygous for a known missense mutation (Arg95Cys) and a novel splicing mutation in the donor site of intron 7 (c.1287+2T>C). Family study showed that his parents were heterozygous carriers of the mutations. To the best of our knowledge, this is the first report of genetically confirmed AE in Korea.

Effects of zinc supplementation on serum zinc concentration and ratio of apo/holo-activities of angiotensin converting enzyme in patients with taste impairment

OBJECTIVE

The aim of the present study was to evaluate the effects of zinc supplementation on hypogeusia, serum zinc concentration and the ratio of apo/holo-activities of angiotensin converting enzyme (ACE ratio) in patients with taste impairment. ACE ratio was used as an index of zinc nutritional status.

METHODS

Forty patients complaining of taste impairment were divided into two groups: zinc deficiency taste impairment (n=12) and idiopathic taste impairment (n=28). Patients with zincemia values of less than 63 microg/dl with no history of other disorder or medication known to cause dysgeusia were diagnosed as zinc deficiency group, while those with the same condition and values more than 64 microg/dl were considered to belong to the idiopathic group. Patients orally received 150 mg of polaprezinc containing 33 mg of zinc every day. Subjective symptom was scored according to visual analogue scale (VAS).

RESULTS

Zinc supplementation improved hypogeusia in both idiopathic and zinc deficiency groups. The mean improvements of VAS were 3.02+/-3.03 in the idiopathic group and 3.13+/-2.53 in the zinc deficiency group. Thus, there were no significant differences in idiopathic and zinc deficiency groups. Significant correlations were found between the improvement of VAS score and the ACE ratio after zinc supplementation in both idiopathic and zinc deficiency groups. On the contrary, significant correlations were not found between the improvement of VAS score and the zinc concentration in the serum after zinc supplementation in both groups.

CONCLUSION

The results of the present study indicated that zinc deficiency is a predominant factor underlying taste impairment and ACE ratio may be a predictor of the prognosis for taste impairment after zinc supplementation, in addition to a more sensitive indicator of zinc nutrition than zinc concentration in the serum.

Age-based differences in hair zinc of Vancouver preschoolers

Marginal zinc deficiency (MZD), the subclinical stage of zinc deficiency, is common in industrialized societies. Serum zinc, the most common biomarker of zinc status, lacks sensitivity and specificity to diagnose this deficiency. Hair zinc, however, is sensitive and specific enough to detect MZD in children. Differences in hair zinc associated with age and sex have been reported. These differences have not been investigated thoroughly; therefore, interpretation of the results of hair analyses is difficult. This cross-sectional study was designed to examine the hair zinc status of a group of Vancouver preschoolers (24-71 months) and assess the age- and sex-based differences in their hair zinc. Hair samples were obtained (n = 719) and analyzed for zinc using inductively coupled plasma mass spectrometry. Our results indicated a mean hair zinc of 115 +/- 43 microg/g with 17% below the low hair zinc cutoff (70 microg/g). Boys and girls had comparable mean hair zinc, while girls had a significantly higher occurrence of low hair zinc than boys (21% vs. 12%). Children <4 years of age had significantly lower mean hair zinc and higher rate of low hair zinc compared to children > or =4. Our study provides important reference values for the hair zinc of healthy North American preschoolers.

Global and regional child mortality and burden of disease attributable to zinc deficiency

BACKGROUND/OBJECTIVES

Zinc is an essential micronutrient and deficiency can lead to an increased risk for infectious diseases and growth retardation among children under 5 years of age. We aimed to estimate disease-specific and all-cause mortality attributable to zinc deficiency.

SUBJECT/METHODS

We estimated the prevalence of zinc deficiency in Latin America, Africa and Asia, where based on zinc availability in the diet and childhood stunting rates, zinc deficiency is widespread. The relative risks of death among zinc-deficient children for diarrhea, malaria and pneumonia were estimated from randomized controlled trials. We used the comparative risk assessment methods to calculate deaths and burden of disease (measured in disability-adjusted life years, DALYs) from each of these three diseases attributable to zinc deficiency in these regions.

RESULTS

Zinc deficiency was responsible for 453,207 deaths (4.4% of childhood deaths), and 1.2% of the burden of disease (3.8% among children between 6 months and 5 years) in these three regions in 2004. Of these deaths, 260,502 were in Africa, 182,546 in Asia and 10,159 in Latin America. Zinc deficiency accounted for 14.4% of diarrhea deaths, 10.4% of malaria deaths and 6.7% of pneumonia deaths among children between 6 months and 5 years of age.

CONCLUSIONS

Zinc deficiency contributes to substantial morbidity and mortality, especially from diarrhea. Zinc supplementation provided as an adjunct treatment for diarrhea may be the best way to target children most at risk of deficiency.

Can zinc be an adjuvant therapy for juvenile onset recurrent respiratory papillomatosis?

OBJECTIVES

To report a severe case of juvenile onset recurrent respiratory papillomatosis (JORRP) controlled by zinc replacement therapy. To review the contemporary adjuvant therapies used in JORRP.

METHODS

The trial of zinc was described in terms of its effect on the inter-surgical interval, site score and clinical symptoms. Long-term follow-up with dose adjustment was detailed. Articles reporting trials of adjuvant therapies over the past 20 years were reviewed in terms of regimen used, mode of assessment, side effects and final outcome.

RESULTS

Zinc was effective in decreasing the severity of the disease, the rate of relapse and the need for surgery. There was an obvious relation between the dose used and the degree of improvement. Prolonged treatment seems to be needed to sustain the positive effect. No side effects were noticed over a 45-month follow-up period. The literature does support the role of zinc in modulating the immune system. Eight adjuvant therapies were reviewed as published in 40 reports. Interferon was the most used substance. It is definitely effective but often associated with relapse upon discontinuation. The effect of cidofovir was favorable yet not dramatic as initially expected. Other less commonly used therapies showed humble effects. The HspE7 vaccine seems to be promising awaiting further trials.

CONCLUSIONS

Zinc replacement therapy may benefit JORRP patients with zinc deficiency and should be investigated in more cases. Several adjuvant therapies are available for use in JORRP. They are generally beneficial though mostly not curative.

Acrodermatitis enteropathica and an overview of zinc metabolism

Acrodermatitis enteropathica is a rare autosomal recessive disorder of zinc deficiency. The genetic defect has been mapped to 8q24 and the defective gene identified as SLC39A4, which encodes the zinc transporter Zip4. The diagnosis is made by way of clinical presentation together with histopathology and laboratory tests. Here we provide an overview of zinc metabolism and a description of inherited and acquired zinc deficiency.

Zinc and the risk for infectious disease

Zinc is an essential micronutrient for human growth, development, and immune function. Zinc deficiency impairs overall immune function and resistance to infection. Mild to moderate zinc deficiency can be best detected through a positive response to supplementation trials. Zinc supplementation has been shown to have a positive effect on the incidence of diarrhea (18% reduction, 95% CI: 7-28%) and pneumonia (41% reduction, 95% CI: 17-59%), and might lead to a decrease in the incidence of malaria. Zinc has also proven to decrease the duration of diarrhea by 15% (95% CI: 5-24%). Maternal zinc supplementation may lead to a decrease in infant infections. Studies assessing the role of zinc supplementation among persons with HIV, tuberculosis, and the common cold have not been conclusive. Two studies have shown zinc supplementation to decrease child mortality by more than 50%. Zinc clearly has an important role in infant and childhood infectious diseases; programs to increase the intake of zinc among deficient populations are needed.

Zinc-responsive dermatosis in dogs: 41 cases and literature review

Forty-one cases of zinc-responsive dermatosis in the dog are described. The Siberian husky was the predominant breed affected. Periocular crusts were the most common clinical sign and parakeratosis was noted in the skin biopsy specimens of all dogs. Treatment with oral zinc ameliorated the clinical signs in most dogs, but cases necessitating other treatments such as parenteral zinc or retinoids are reported. The authors recommend a starting dose of 2-3 mg kg-1 elemental zinc per day in the treatment of this disorder.

Metallothionein mRNA in monocytes and peripheral blood mononuclear cells and in cells from dried blood spots increases after zinc supplementation of men

A specific, sensitive and reliable index for assessment of human zinc status has not been developed, and continues to present a considerable challenge for nutritionists in the trace element field. We have focused on metallothionein (MT) expression as a potential index. A protocol involving 16 men and a 10-d supplementation period plus a 4-d postsupplementation period was used to examine the relative response of MT expression in erythrocytes, monocytes, peripheral blood mononuclear cells (PBMC) and cells from a dried blood spot (DBS). Zinc was supplemented at the current adult male recommended dietary allowance (RDA) of 15 mg. Erythrocyte MT protein, as measured by ELISA, increased gradually to about twofold over the placebo group during zinc supplementation and remained elevated for 4 d postsupplementation. Competitive reverse transcriptase-polymerase chain reaction showed that MT mRNA levels in both monocytes and PBMC increased (up to 4.7- and 2.7-fold, respectively) after 2 d of supplementation, with greater expression in monocytes compared with PBMC. Total RNA extracted from dried blood spots, representing cells from 50 microL of blood, showed a comparable change in MT mRNA upon zinc supplementation. In each leukocyte population isolated, when zinc supplementation was withdrawn, MT mRNA levels decreased. Collectively, these experiments show that, in men, MT gene expression increases during supplementation at the RDA, and that the DBS sampling method will be of value in measuring MT expression in a variety of clinical and survey situations.

Acrodermatitis enteropathica-like eruption in an infant with nonketotic hyperglycinemia

Acrodermatitis enteropathica is a rare inherited disorder characterized by zinc deficiency and a triad of dermatitis, diarrhea, and alopecia. It is an autosomal recessive condition thought to be due to the inability to absorb zinc from the gastrointestinal tract. Acquired zinc deficiency due to a variety of etiologies may produce a similar clinical picture. These causes include inadequate supply, malabsorption, and low zinc stores. In addition to zinc, deficiencies of other nutrients such as branched chain amino acids have induced an acrodermatitis enteropathica-like eruption. We describe a case of a 26-month-old boy with a rare inborn error of metabolism known as nonketotic hyperglycinemia who developed an acrodermatitis enteropathica-like eruption. In addition to zinc deficiency, the patient was deficient in branched chain amino acids due to a low protein diet instituted to reduce his elevated glycine levels. The rash did not respond to zinc replacement alone, and therefore is most likely a combination of amino acid and zinc deficiency. Acrodermatitis enteropathica-like eruptions have been described in other conditions that cause decreased serum amino acids, such as maple syrup urine disease and organic acidurias. This is the first case describing an association between acrodermatitis enteropathica and nonketotic hyperglycinemia.

Urinary zinc excretion and zinc status of patients with beta-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. Urinary N-acetyl-beta-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 (micromol/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.

Long-term effects of iron:zinc interactions on growth in rats

The influence of iron (Fe) on the bioavailability and functional status of zinc (Zn) was studied in young rats using metabolic balances and tissue dosages, which were compared to growth. Diets supplied adequate intakes of Fe (45 and 300 mg/kg diet) and Zn (14 and 45 mg/kg) for 2 mo. Two metabolic balance determinations were performed that were correlated for Zn and Fe during the first and the last weeks of the study. A significant effect of Fe supply, but not of Zn was displayed on Fe absorption; both Fe and Zn diet concentrations had a significant influence on Zn absorption. Fe and Zn organ contents were significantly correlated with the amount absorbed during the two metabolic balances. There was a positive correlation between liver and muscle Fe and Fe absorption, and Fe absorption and muscle Zn, as well as a negative one with liver Zn; a positive correlation was displayed between Zn absorption and Zn organ content. No correlation was found between Zn absorption and Fe tissue content. Growth was correlated with Zn, but not with Fe absorption during both balances. A positive correlation was displayed between growth and Zn liver content, and a negative one with Fe liver content. Care must be taken to give growing subjects balanced diets or supplementation, since the negative interactions between these trace elements are likely to persist as long as the diet is given.

Growth characteristics in laboratory animals fed zinc-deficient, copper-deficient, of histidine-supplemented diets

The effects of growth in male Wistar rats and female Swiss Random mice were studied during dietary zinc (Zn) deficiency, copper (Cu) deficiency, and during the feeding of a histidine (His) supplement Growth was analyzed by comparing the characteristics of the decreasing exponential growth curve plotted for the experimental period. When the animals were pair-fed the experimental diets, the growth pattern in the animals remained unaltered. The growth rate decreased during Zn deficiency by a factor of 0.64 over a period of 10 d (male young adult rats) and by a factor of 0.76 over a period of 28 d (female weaning mice). On the other hand, a supplement of His increased the growth rate by a factor of 1.11 (in the mice). The effect of Cu deficiency on the growth rate was not statistically significant (in the rats). However, Cu deficiency causes effects in the Zn status that may over-compensate minor growth retardation during Cu deficiency. The effect of the His supplement is explained by its having an effect on the Zn-absorption (His enhancing Zn transport over the gut) and by a stimulating effect of this amino acid on the thickness of the growth plate in bone.