Folates are tripartite molecules comprising pterin, para-aminobenzoate (PABA), and glutamate moieties, which are essential cofactors involved in DNA and amino acid synthesis. The obligately intracellular Chlamydia species have lost several biosynthetic pathways for essential nutrients which they can obtain from their host but have retained the capacity to synthesize folate. In most bacteria, synthesis of the pterin moiety of folate requires the FolEQBK enzymes, while synthesis of the PABA moiety is carried out by the PabABC enzymes. Bioinformatic analyses reveal that while members of Chlamydia are missing the genes for FolE (GTP cyclohydrolase) and FolQ, which catalyze the initial steps in de novo synthesis of the pterin moiety, they have genes for the rest of the pterin pathway. We screened a chlamydial genomic library in deletion mutants of Escherichia coli to identify the "missing genes" and identified a novel enzyme, TrpFCtL2, which has broad substrate specificity. TrpFCtL2, in combination with GTP cyclohydrolase II (RibA), the first enzyme of riboflavin synthesis, provides a bypass of the first two canonical steps in folate synthesis catalyzed by FolE and FolQ. Notably, TrpFCtL2 retains the phosphoribosyl anthranilate isomerase activity of the original annotation. Additionally, we independently confirmed the recent discovery of a novel enzyme, CT610, which uses an unknown precursor to synthesize PABA and complements E. coli mutants with deletions of pabA, pabB, or pabC. Thus, Chlamydia species have evolved a variant folate synthesis pathway that employs a patchwork of promiscuous and adaptable enzymes recruited from other biosynthetic pathways. Importance: Collectively, the involvement of TrpFCtL2 and CT610 in the tetrahydrofolate pathway completes our understanding of folate biosynthesis in Chlamydia. Moreover, the novel roles for TrpFCtL2 and CT610 in the tetrahydrofolate pathway are sophisticated examples of how enzyme evolution plays a vital role in the adaptation of obligately intracellular organisms to host-specific niches. Enzymes like TrpFCtL2 which possess an enzyme fold common to many other enzymes are highly versatile and possess the capacity to evolve to catalyze related reactions in two different metabolic pathways. The continued identification of unique enzymes such as these in bacterial pathogens is important for development of antimicrobial compounds, as drugs that inhibit such enzymes would likely not have any targets in the host or the host's normal microbial flora.

BACKGROUND

This study investigated the association of neural tube defects (NTDs) with maternal periconceptional intake of folic acid-containing supplements and dietary nutrients, including folate, among deliveries that occurred after folic acid fortification in selected California counties.

METHODS

The population-based case-control study included fetuses and live born infants with spina bifida (189) or anencephaly (141) and 625 nonmalformed, live born controls delivered from 1999 to 2003. Mothers reported supplement use during telephone interviews, which included a 107-item food frequency questionnaire. For dietary nutrients, intakes <25th, 25th to <75th (reference), and>> or =75th percentile were compared, based on control distributions.

RESULTS

After adjustment for potential confounders, any versus no supplement intake resulted in ORs of 0.8 (95% CI, 0.5-1.3) for anencephaly and 0.8 (95% CI, 0.6-1.2) for spina bifida. After stratification by maternal intake of vitamin supplements, most factors in the glycemic pathway were not associated with either NTD, with the exception of low levels of fructose and glucose that were significantly associated with anencephaly. Some nutrients that contribute to one-carbon metabolism showed lowered risks (folate, riboflavin, vitamins B(6) and B(12)); others did not (choline, methionine, zinc). Antioxidant nutrients tended to be associated with lowered risks (vitamins C, E, A, beta-carotene, lutein).

CONCLUSIONS

Mothers' intake of vitamin supplements was modestly if at all associated with a lowered risk of NTDs. Dietary intake of several nutrients contributing to one-carbon metabolism and oxidative stress were associated with reduced NTD risk.

OBJECTIVE

To measure erythrocyte glutathione reductase (EGR) activity and riboflavin status, and their relations to disease activity, in rheumatoid arthritis patients compared to healthy controls.

METHODS

Patients with rheumatoid arthritis were classified as active if there were features of articular inflammation which required initiation or change of disease modifying therapy, and as inactive if they had little evidence of articular inflammation. EGR was measured in patients and healthy controls by a functional assay with or without the addition of flavin adenine dinucleotide (FAD). The ratio of stimulated EGR (with FAD added) to basal EGR (no added FAD), which measures riboflavin status, is known as the EGR activation coefficient (EGRAC). An EGRAC>> or = 1.3 represents biochemical riboflavin deficiency.

RESULTS

91 patients with rheumatoid arthritis, including 57 with active disease, and 220 healthy controls were studied. Both basal and stimulated EGR were significantly higher in patients with rheumatoid arthritis (P = 0.0001) than in controls. Biochemical riboflavin deficiency was identified in 41% controls and 33% patients with active rheumatoid arthritis but was significantly less frequent (9%) in patients with inactive compared to active disease (P = 0.02) or healthy controls (P = 0.0006). Pain score, articular index, C reactive protein, and erythrocyte sedimentation rate were increased in patients with riboflavin deficiency (all P < 0.02).

CONCLUSIONS

Higher basal and stimulated EGR might be expected in patients with rheumatoid arthritis in response to chronic oxidative stress due to synovial inflammation. The association of riboflavin deficiency with increased disease activity suggests that impaired EGR activity could facilitate continuing inflammation in these patients.

Feeding experiments with Ashbya gossypii followed by NMR analysis of the resulting riboflavin showed incorporation of deuterium from D-[2-2H]ribose at C-2' and from D-[1-2H]ribose in the pro-R position at C-1' of the ribityl side chain. The results rule out an Amadori rearrangement mechanism for the reduction of the ribosylamino to the ribitylamino linkage and point to formation of a Schiff base that is reduced stereospecifically opposite to the face from which the oxygen has departed. As prerequisite for the analysis, the 1H NMR signals for the pro-R and pro-S hydrogens at C-1' of 6,7-dimethyl-8-ribityllumazine and riboflavin and its tetraacetate were assigned with the aid of synthetic stereospecifically deuteriated samples.

Epidemiologic data suggest that increasing folate intake may protect against colorectal cancer. Riboflavin may interact with folate to modulate the effect. A double-blind randomized placebo-controlled intervention study (the FAB2 Study) was carried out in healthy controls and patients with colorectal polyps (adenomatous and hyperplastic) to examine effects of folic acid and riboflavin supplements on biomarkers of nutrient status and on putative biomarkers of colorectal cancer risk (DNA methylation and DNA damage; to be reported elsewhere). Ninety-eight healthy controls and 106 patients with colorectal polyps were stratified for the thermolabile variant of methylene tetrahydrofolate reductase, MTHFR C677T, and were randomized to receive 400 microg of folic acid, 1,200 microg of folic acid, or 400 microg of folic acid plus 5 mg of riboflavin or placebo for 6 to 8 weeks. Blood samples and colon biopsy samples were collected for the measurement of biomarkers of folate and riboflavin status. Supplementation with folic acid elicited a significant increase in mucosal 5-methyl tetrahydrofolate, and a marked increase in RBC and plasma, with a dose-response. Measures of riboflavin status improved in response to riboflavin supplementation. Riboflavin supplement enhanced the response to low-dose folate in people carrying at least one T allele and having polyps. The magnitude of the response in mucosal folate was positively related to the increase in plasma 5-methyl tetrahydrofolate but was not different between the healthy group and polyp patients. Colorectal mucosal folate concentration responds to folic acid supplementation to an extent comparable to that seen in plasma, but with a suggestion of an upper limit.

OBJECTIVE

To evaluate the efficacy of antioxidant supplementation in preventing kwashiorkor in a population of Malawian children at high risk of developing kwashiorkor.

METHODS

Prospective, double blind, placebo controlled trial randomised by household.

METHODS

8 villages in rural southern Malawi.

METHODS

2372 children in 2156 households aged 1-4 years were enrolled; 2332 completed the trial.

METHODS

Daily supplementation with an antioxidant powder containing riboflavin, vitamin E, selenium, and N-acetylcysteine in a dose that provided about three times the recommended dietary allowance of each nutrient or placebo for 20 weeks.

METHODS

The primary outcome was the incidence of oedema. Secondary outcomes were the rates of change for weight and length and the number of days of infectious symptoms.

RESULTS

62 children developed kwashiorkor (defined by the presence of oedema); 39/1184 (3.3%) were in the antioxidant group and 23/1188 (1.9%) were in the placebo group (relative risk 1.70, 95% confidence interval 0.98 to 2.42). The two groups did not differ in rates of weight or height gain. Children who received antioxidant supplementation did not experience less fever, cough, or diarrhoea.

CONCLUSIONS

Antioxidant supplementation at the dose provided did not prevent the onset of kwashiorkor. This finding does not support the hypothesis that depletion of vitamin E, selenium, cysteine, or riboflavin has a role in the development of kwashiorkor.

In a semi-defined minimal medium for cultivation of Plasmodium falciparum, ribose, mannose, fructose, galactose, and maltose could not replace glucose. Hypoxanthine was the preferred purine source for the parasite over adenine, guanine, inosine, adenosine and guanosine although all supported growth equally. Inhibitors of nucleoside uptake had low potency in killing the parasites but depressed incorporation of [3H]adenosine more than [3H]hypoxanthine. Glutamate could not be replaced by 5-oxoproline, indicating that the gamma-glutamyl transferase pathway for amino acid uptake is probably not found in this organism. Adenine, nicotinamide, and orotic acid could not supplement glutamine-deficient medium. The pyridoxine antagonists isoniazid and 4-deoxypyridoxine were reversed by amino acid supplementation, suggesting that transaminases may be targets of these drugs. Orotic acid, but not glutathione or its amino acid components, partially reversed the effects of 8-methylamino-8-desmethyl riboflavin. Thus, the flavin enzyme, dihydroorotic acid dehydrogenase, but not glutathione reductase, appears to be a target of this riboflavin antagonist. Five biotin antagonists had no significant activity. The choline antagonist 2-(tert-butylamino)ethanol and thiamin uptake inhibitors had nonspecific inhibitory effects, which were not reversed by the respective target vitamin. Buthionine sulfoximine and methionine sulfoximine, inhibitors of glutathione synthesis, had significant oxygen-dependent toxicity. Six sulfonamides showed marked variation in potency and efficacy. Sulfathiazole and sulfadoxine were reversed differentially by p-aminobenzoic acid, folic acid, and folinic acid. Folinic acid was more effective than folic acid at reversing the toxicity of the dihydrofolate reductase inhibitors aminopterin and pyrimethamine; p-amino-benzoic acid had no effect.

The major histocompatibility complex class I-related molecule MR1 can bind a novel class of antigens, namely a family of related small organic vitamin B metabolites. When bound to MR1 these metabolites are presented to a population of innate-like T cells, mucosal-associated invariant T (MAIT) cells that express a semi-invariant T cell receptor (TCR). Several non-activating and activating MR1-restricted ligands have been described, which are the degradation products of, or intermediates of, vitamin B9 (folic acid) or vitamin B2 (riboflavin), respectively. The MAIT-activating intermediates of the riboflavin synthesis pathway are unique to a wide range of microbes, and accordingly represent a molecular signature of microbial infection. Recently insights into the binding of these vitamin B metabolites to MR1, and subsequent recognition by the MAIT TCR, have been gleaned, illustrating a novel antigen presentation system.

Infection and trauma cause inflammatory stress in patients. Tissue damage, enhanced inflammatory mediator production and suppressed lymphocyte function may occur as a consequence. The antioxidative vitamins, ascorbic acid and the tocopherols, are important not only for limiting tissue damage but also in preventing increased cytokine production which is a consequence of excessive activation of NF kappa B. Glutathione is a major endogenous antioxidant and is important for lymphocyte replication. Two vitamins, vitamin B6 and riboflavin participate in the maintainance of glutathione status. The former vitamin acts as a cofactor in the synthesis of cysteine (the rate limiting precursor for glutathione biosynthesis) and the latter vitamin is a cofactor for glutathione reductase. Deficiencies in tocopherol, vitamin B6 and riboflavin reduce cell numbers in lymphoid tissues of experimental animals and produce functional abnormalities in the cell mediated immune response. Ascorbic acid and tocopherols exert anti-inflammatory effects in studies in man and animals. In humans, dietary supplementation with ascorbic acid, tocopherols and vitamin B6 enhances a number of aspects of lymphocyte function. The effect is most apparent in the elderly.

BACKGROUND

To examine if different pathogen-reduction technologies (PRTs) induce different degrees of platelet (PLT) storage lesion.

METHODS

Twenty-seven split triple-dose apheresis PLTs were PRT treated using ultraviolet light with either riboflavin (M) or psoralen (I) or remained untreated (C). Samples taken on days (d) 0 to 8 were analysed for PLT count, blood gas (pH, pO(2) and pCO(2)), metabolism (lactate, glucose, ATP content), in vitro function [swirling, hypotonic shock response (HSR) and aggregation], activation (p-selectin expression) and cellular integrity (JC-1 signal, annexin A5 release).

RESULTS

Platelet counts of all study groups remained unchanged during storage indicating that PRT treatment did not induce relevant cell lysis. Although M units demonstrated the highest values for HSR until d5, PRT treatment lowered all parameters examined with significant differences to untreated controls by d7 of storage. During final storage, M was significantly superior over I for HSR, aggregation with TRAP-6 as agonist (collagen was similar), annexin A5 release and JC-1 signal. Regarding blood gas and metabolic analysis, the most evident effect of PRT was an elevated glycolytic flux combined with higher acidity due to increased lactate accumulation. Most likely due to impaired O(2) consumption, pH and ATP decreased more rapidly in I relative to C and M.

CONCLUSIONS

Pathogen reduction technology-treated PLTs remained comparable to untreated units throughout 7 days of storage. Mitochondria-based oxidative respiration appeared up-regulated after the riboflavin-based PRT. Compared to the psoralen-based PRT, this resulted in significantly better ATP maintenance and in vitro function during the last storage period (d7, d8).

The enzymes involved in the biosynthesis of riboflavin represent attractive targets for the development of drugs against bacterial pathogens, because the inhibitors of these enzymes are not likely to interfere with enzymes of the mammalian metabolism. Lumazine synthase catalyzes the penultimate step in the riboflavin biosynthesis pathway. A number of substituted purinetrione compounds represent a new class of highly specific inhibitors of lumazine synthase from Mycobacterium tuberculosis. To develop potent antibiotics for the treatment of tuberculosis, we have determined the structure of lumazine synthase from M. tuberculosis in complex with two purinetrione inhibitors and have studied binding via isothermal titration calorimetry. The structures were determined by molecular replacement using lumazine synthase from Saccharomyces cerevisiae as a search model and refined at 2 and 2.3 A resolution. The R-factors were 14.7 and 17.4%, respectively, and the R(free) values were 19.3 and 26.3%, respectively. The enzyme was found to be a pentamer consisting of five subunits related by 5-fold local symmetry. The comparison of the active site architecture with the active site of previously determined lumazine synthase structures reveals a largely conserved topology with the exception of residues Gln141 and Glu136, which participate in different charge-charge interactions in the core space of the active site. The impact of structural changes in the active site on the altered binding and catalytic properties of the enzyme is discussed. Isothermal titration calorimetry measurements indicate highly specific binding of the purinetrione inhibitors to the M. tuberculosis enzyme with dissociation constants in micromolar range.

The term 'lipid-based nutrient supplements' (LNS) refers generically to a range of fortified, lipid-based products, including products like Ready-to-Use Therapeutic Foods (RUTF) (a large daily ration with relatively low micronutrient concentration) as well as highly concentrated supplements (1-4 teaspoons/day, providing <100 kcal/day) to be used for 'point-of-use' fortification. RUTF have been successfully used for the management of severe acute malnutrition (SAM) among children in emergency settings. Recent research on smaller doses of LNS for prevention of malnutrition has created interest in their potential use in emergency settings to ensure a more nutritionally adequate ration for the most vulnerable groups [e.g. infants and children between 6 and 24 months of age, and pregnant and lactating women (PLW)]. Currently, the main food and nutrition interventions in emergency settings include general food distribution (GFD) rations, which are provided to the affected population as a whole, and selective (or supplementary) feeding programs (SFP), which are to be provided to nutritionally vulnerable or malnourished individuals. In addition to logistical and operational challenges that may limit the intended effect of these programs, the nutritional quality of the food commodities provided may be insufficient to meet the needs of infants and young children and PLW. Because these subgroups have particularly high nutrient needs for growth and development, meeting these needs is challenging in settings where the ration is limited to a few food commodities, with little access to a diverse diet and bioavailable sources of micronutrients. In recent years, there has been increased attention to adding micronutrient interventions, on top of the other food-based interventions (such as GFDs and SFPs), to fill micronutrient gaps in diets in emergency settings. The focus of this document is the potential role of LNS in meeting the nutritional needs of these vulnerable subgroups, with the goal of preventing malnutrition in emergency-affected populations. The document addresses the desired nutritional formulation of LNS for these target groups, taking into account the expected bioavailability of relevant nutrients and toxicity concerns. It also discusses the recommended chemical forms of the fortificants in LNS; stability and shelf-life considerations; production, packaging and distribution of LNS in the context of emergencies; and cost implications of the addition of LNS to current GFD rations for vulnerable groups. To develop the desired nutritional formulation of LNS for these purposes, we calculated the current nutrient content of commonly provided GFD rations and determined the nutritional 'gaps' (of both micro- and macronutrients) of these rations for each of the target groups (i.e. children 6-35 months of age and PLW). For fat and protein, both quantity and quality were evaluated. Through an iterative process, we determined the formulation of a small dose of LNS that would best meet the recommended nutrient intakes for each group in combination with other foods in the GFD ration [composed of a grain, pulse, oil, sugar and salt, but excluding a fortified blended food (FBF)], as well as breast milk for children 6-24 months of age, while avoiding excess levels of any one nutrient to the extent possible. The composition of the LNS used for these calculations is based on an existing LNS product (Nutributter, Malaunay, France, Nutriset), but with less sugar and more oil. Two different approaches were used: (1) developing two different formulations of LNS, one to be used for infants and children 6-35 months of age and a separate one for PLW; and (2) developing a single formulation that could be used for all of these subgroups. We used commodity cost data to estimate the cost of adding an LNS product to the GFD ration. The results indicate that the typical GFD ration currently provided in emergency settings--based on cereals, pulse, an FBF such as corn-soy blend (CSB), oil, salt and sugar-does not meet the nutritional needs of infants and young children and PLW. The hypothetical intake from a ration composed of food aid commodities (based on the current USAID/USDA specifications for exported food aid commodities used in emergency settings), and including breast milk for children 6-24 months of age, provided less than 75% of the recommended intake for several micronutrients for certain age/physiologic groups, including calcium, iron, zinc, B vitamins such as riboflavin, B6 and B12, and fat-soluble vitamins such as D, E and K. It also generally contained lower than recommended levels of fat and essential fatty acids. The initial LNS formulation for each target group was designed to provide 100% of the recommended amount (RDA or RNI) for most micronutrients per daily dose (20 g, approximately 118 kcal) of LNS. This would ensure consumption of the recommended levels of each nutrient even if the 'base' diet changed. However, because such a formulation could provide excess amounts of certain nutrients when consumed in combination with the 'base' diet (especially when the 'base' diet contains fortified foods), we made adjustments in the LNS formulation when there was a risk of greatly exceeding the Upper Level for certain subgroups and there were relevant concerns about adverse effects from chronic consumption of such amounts. For most nutrients, consumption of toxic amounts is highly unlikely with the proposed LNS formulations. The 'one-size' LNS formulation was designed so that one 'dose' (20 g) would be provided to infants and young children and two 'doses' (i.e. 40 g/day) would be provided to PLW. This 'one-size' formulation was based on the LNS formulation developed for children 6-35 months of age. Although the resulting formulation is not a perfect match for the unique nutritional needs of each subgroup, there are several practical advantages to using such an approach. As anticipated, addition of LNS to the GFD ration, even after eliminating the FBF (e.g. CSB), increases the cost. The 'revised' ration without CSB but with LNS would cost 34-52% more (food only) than the 'typical' GFD diet for a hypothetical mother-infant pair, depending on how many LNS 'doses' were provided to the mother. However, depending on the contribution of food costs to overall program costs, the overall increase in costs may be significantly less. Although cost is an important consideration, options to improve the nutritional quality of foods provided in emergency settings should also be assessed with regard to effectiveness in maintaining and improving nutritional outcomes. Another consideration is whether a specialized product like LNS is more easily targeted to the individuals for whom it is intended, thus reducing inter- and intra-household sharing, a common concern with other fortified products such as CSB. This could have substantial cost implications because programs usually compensate for sharing by inflating the amount of FBF provided. This document is intended to be a starting point for considering the incorporation of LNS in the food packages provided in emergency settings. Our goal was to examine the potential nutritional benefits but also the challenges of adopting such a strategy. There are many different options for emergency nutrition programs, and there are also many considerations governing which option to choose. This document is intended to encourage further evaluation of all of these options.

The aim of this study was to describe the nutrients provided to Australian adults by the breakfast meal and to compare the food and nutrient intakes and health of regular breakfast eaters and breakfast skippers. The Australian Bureau of Statistics was commissioned to undertake additional analysis of data collected in the 1995 Australian National Nutrition Survey (NNS). The survey included 24-h recalls, physical measurements and a food habits questionnaire collected during the period February 1995-March 1996, with a nationally representative sample of 10,851 Australians aged 19 years and older. The median nutrient intakes at breakfast and the proportion of the daily total contributed by breakfast were calculated. Differences between regular breakfast eaters and breakfast skippers in terms of nutrient intake, body mass index and health status were compared using Student t-tests. The findings show the typical Australian breakfast was low in fat, high in carbohydrate and a good source of thiamin, riboflavin, niacin, calcium and magnesium. In the NNS regular breakfast eaters had more adequate diets overall, particularly those aged 65+ years. People who did not eat breakfast cereal were much more likely to have inadequate nutrient intakes, especially of thiamin, riboflavin, calcium, magnesium and iron. Regular breakfast eaters were more likely to rate their health as excellent or good than those who skip breakfast, but there was no difference between the fat intake or the body mass index of regular breakfast eaters compared with breakfast skippers. Regular breakfast consumption is associated with better diets for adults overall.

OBJECTIVE

The objective of the present study was to assess whether weight status, nutrient intake and dietary adequacy were associated with breakfast consumption patterns.

METHODS

A representative sample of the US population was used in a secondary analysis of nutrient intake/diet quality and weight status by breakfast consumption patterns.

METHODS

The 1999-2002 National Health and Nutrition Examination Survey (NHANES).

METHODS

The study sample included African-American (AA) children aged 1-12 years (n 1389).

RESULTS

Forty-five per cent of children aged 1-5 years and 38 % of those aged 6-12 years consumed ready-to-eat cereal (RTEC) at breakfast; while 7.4 % and 16.9 % in those age groups skipped breakfast, respectively. The lowest mean BMI (P <or= 0.05) and mean waist circumference (P <or= 0.05) was found in children 1-12 years of age who consumed RTEC at breakfast compared with other consumption groups. RTEC breakfast consumers had the highest mean intakes of vitamins A, B6 and B12, thiamine, <em>riboflavin</em>, niacin, folate, Ca, Fe and Zn (P <or= 0.05) and the highest Mean Adequacy Ratio (P <or= 0.05). RTEC breakfast consumers also had the highest intake of carbohydrates and total sugars, and the lowest intakes of total fat (P <or= 0.05).

CONCLUSIONS

Consuming RTEC at breakfast was associated with improved weight and nutrient adequacy in AA children. AA children in all breakfast categories still had mean intakes of most nutrients below recommended levels. The implications are that consuming a breakfast meal should be encouraged in these children, and that RTEC at breakfast provides important nutrients and may help promote a healthy weight.

A Canadian Indian family is described in which three of the children were mentally retarded, and had seizures and other neurological abnormalities. They had chronic metabolic acidosis associated with elevated blood levels of lactate, pyruvate, and alanine. Two of the children excreted large amounts of pyruvic and alpha-ketoglutaric acids in the urine and had elevated plasma levels of glutamic acid and proline. Hypoglycemia occurred with fasting in two of the children. Treatment with pharmacological doses of thiamine, lipoic acid, biotin, riboflavin, and various dietary regimes was without effect. One child died at 3 1/2 months and another at 4 1/2 months; the third is still alive at 23 months of age. Enzyme assays revealed a low level of activity of both the pyruvate and alpha-ketoglutarate dehydrogenase complexes in cultured fibroblasts of one of the sibs. These patients appeared to have partial defects in the oxidation of pyruvate, as well as of alpha-ketoglutarate within the tricarboxylic acid cycle.

OBJECTIVE

The efficacy of some nonpharmacologic therapies appears to approach that of most drugs used for the prevention of migraine and tension-type headaches. These therapies often carry a very low risk of serious side effects and frequently are much less expensive than pharmacologic therapies. Considering this combination of efficacy, minimal side effects, and cost savings, medications should generally not be prescribed alone but rather in combination with nonpharmacologic therapies.

RESULTS

In addition to the established nonpharmacologic therapies, such as biofeedback, relaxation training, butterbur, riboflavin, magnesium, and coenzyme Q10 (CoQ10) supplementation, recent data provide support for the use of aerobic exercise and acupuncture. Discovery of the high incidence of the C677T mutation of the methylenetetrahydrofolate reductase gene, MTHFR, and attendant elevation of homocysteine levels in patients with migraine with aura led to a trial of cyanocobalamin, folate, and pyridoxine in these patients. This trial showed that taking these three supplements resulted in a reduction of homocysteine levels and improvement of migraines.

CONCLUSIONS

Therapies proven (to various degrees) to be effective for migraine include aerobic exercise; biofeedback; other forms of relaxation training; cognitive therapies; acupuncture; and supplementation with magnesium, CoQ10, riboflavin, butterbur, feverfew, and cyanocobalamin with folate and pyridoxine.

Deficiencies of iron and iodine are common in West Africa, and salt is one of very few food vehicles available for fortification. Salt dual-fortified with iodine and micronized ground ferric pyrophosphate (FePP) was tested for its efficacy in rural, tropical Côte d'Ivoire. First, salt and iron intakes, and iron bioavailability were estimated using 3-d weighed food records in 24 households. Local iodized salt was then fortified with 3 mg Fe/g salt as ground FePP (mean particle size = 2.5 mum), and stability, sensory and acceptability trials were done. The dual fortified salt (DFS) was distributed to households and its efficacy compared with that of iodized salt (IS) in a 6-mo, double-blind trial in 5- to 15-y-old iron-deficient children (n = 123). All children were dewormed at baseline. After 6 mo, serum ferritin (SF) and transferrin receptor (TfR) concentrations as well as body iron stores improved significantly in the DFS group but not in the IS GROUP (P < 0.05). Body iron increased from 4.6 +/- 2.7 to 5.9 +/- 2.7 mg/kg (mean +/- SD) in the DFS group; concentrations before and after treatment in the IS group were 5.5 +/- 2.9 and 5.6 +/- 3.1 mg/kg, respectively. The hemoglobin concentration and the prevalence of anemia did not change in either group. The prevalences of malaria, soil-transmitted helminths, and riboflavin deficiency were 55, 14, and 66%, respectively. In tropical West Africa, low-grade salt fortified with micronized ground FePP increased body iron stores but not hemoglobin in children. Iron utilization may have been impaired by the high prevalence of malaria and concurrent nutrient deficiencies.

Under microaerophilic conditions Salmonella typhimurium LT2 synthesizes cobalamin, during which 5,6-dimethylbenzimidazole is formed from riboflavin. We report here that in an anoxic environment S. typhimurium did not form cobalamin, but rather adenylcobamide, 2-methyladenylcobamide, and cobyric acid. This indicated that S. typhimurium, like other microorganisms that synthesize 5,6-dimethylbenzimidazole from riboflavin, requires oxygen for the formation of the cobalamin base.

Since the late 1990s corneal crosslinking (CXL) has been proposed as a new possibility to stop progression of keratoconus or secondary corneal ectasia, with the promising aim to prevent progressive visual loss due to the evolution of the pathology and to delay or avoid invasive surgical procedures such as corneal transplantation. The possibility of strengthening corneal tissue by means of a photochemical reaction of corneal collagen by the combined action of Riboflavin and ultraviolet A irradiation (UVA), radically modified the conservative management of progressive corneal ectasia. This is a review of the state of the art of CXL, reporting basic and clinical evidence. The paper describes basic principles, advantages and limits of different CXL techniques and possible future evolution of the procedure.

OBJECTIVE

This 6-week open-label trial of naltrexone was conducted in a preliminary fashion to determine whether naltrexone would be safe, well tolerated, and lead to a reduction in alcohol consumption in adolescents with alcohol dependence.

METHODS

Five outpatient treatment-seeking adolescents who met Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria for alcohol dependence were recruited. The Child Schedule for Schizophrenia and Affective Disorders (K-SADS), Structured Clinical Interview for DSM (SCID), and the Family History Questionnaire were administered at baseline. The Time-Line Follow-Back (TLFB) and two craving scales (Adolescent Obsessive Compulsive Drinking Scale [A-OCDS] and a craving analog scale) were administered at baseline and weekly thereafter. Each subject received a 10-day supply of naltrexone (50 mg) and a 100-mg riboflavin capsule. Subjects were instructed to take naltrexone and riboflavin simultaneously.

RESULTS

Overall, the average drinks per drinking day (DDD) decreased significantly from baseline to the end of week 6 with an average reduction of 7.61 standard drinks. There was a significant reduction in the average A-OCDS total score, A-OCDS Irresistibility subscale score, and craving analog score. Nausea was the only side-effect reported, and there were no elevations of liver enzymes. Naltrexone was well tolerated by the alcohol-dependent adolescent.

CONCLUSIONS

Our data suggest that naltrexone is safe and well tolerated in adolescent alcoholics. Naltrexone may lead to a significant reduction in alcohol consumption and craving in adolescent alcoholics, but larger, randomized, controlled trials are needed.

OBJECTIVE

To report a case of severe corneal endothelial damage after collagen cross-linking treatment in a 37-year-old man with progressive keratoconus with a corneal thickness of more than 400 μm.

METHODS

After central epithelial debridement, the left cornea was cross-linked for 25 minutes using dextran-riboflavin solution and UV-A light of 370 nm with an irradiance of 3.0 mW/cm2. One month after cross-linking treatment, the patient presented with massive corneal edema. He was treated with 1% prednisolone and carboxymethylcellulose 1% eyedrops 4 times a day for 3 months. Specular microscopy with endothelial cell counting was performed after resolution of the corneal edema 6 months after cross-linking.

RESULTS

Despite intense treatment, a ring-shaped corneal scar remained, and uncorrected visual acuity was finger counting. Cell density after resolution was 1776 cells per square millimeter in the affected eye compared with 2978 cells per square millimeter in the untreated fellow eye.

CONCLUSIONS

Corneal thickness is not the only factor for corneal endothelial damage after cross-linking procedure.

OBJECTIVE

To evaluate the safety and efficacy of intrastromally applied collagen cross-linking (CXL) in a comparative contralateral eye study of topography-guided femtosecond laser-assisted hyperopic LASIK.

METHODS

Thirty-four consecutive patients with hyperopia and hyperopic astigmatism elected to have bilateral topography-guided LASIK and were randomized to receive a single drop of 0.1% sodium phosphate riboflavin solution under the flap followed by 3-minute exposure of 10 mW/cm2 ultraviolet A (UVA) light with the flap realigned in one eye (CXL group) and no intrastromal CXL in the contralateral eye (no CXL group). All eyes were treated with the WaveLight FS200 femtosecond laser and WaveLight EX500 excimer laser (Alcon Laboratories Inc). Refractive error and keratometric, topographic, and tomographic measurements were evaluated over mean follow-up of 23 months.

RESULTS

Preoperatively, mean spherical equivalent refraction was +3.15 +/- 1.46 diopters (D) and +3.40 +/- 1.78 D with a mean cylinder of 1.20 +/- 1.18 D and 1.40 +/- 1.80 D and mean uncorrected distance visual acuity (UDVA) (decimal) of 0.1 +/- 0.26 and 0.1 +/-0.25 in the CXL and no CXL groups, respectively. At 2 years postoperatively, mean spherical equivalent refraction was -0.20 +/- 0.56 D and +0.20 +/- 0.40 D with mean cylinder of 0.65 +/- 0.56 D and 0.76 +/- 0.72 D and mean UDVA of 0.95 +/- 0.15 and 0.85 +/- 0.23 in the CXL and no CXL groups, respectively. Eyes with CXL demonstrated a mean regression from treatment of +0.22 +/- 0.31 D, whereas eyes without CXL showed a statistically significant greater regression of +0.72 +/- 0.19 D (P = .0001).

CONCLUSIONS

Topography-guided hyperopic LASIK with or without intrastromal CXL is safe and effective, with greater long-term efficacy (less regression) in eyes with CXL. Our data suggest that the regression seen with hyperopic LASIK may be related to biomechanical changes in corneal shape over time.