Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review.

A considerable number of studies have examined vitamin D status during pregnancy. Although data from observational studies denote vitamin D hypovitaminosis (deficiency or insufficiency) during pregnancy is associated with a plethora of adverse maternal and neonatal outcomes, data from interventional (supplementation) trials fail to reveal a significant impact on maternal and offspring health. The aim of this narrative review was to critically appraise the methodology of the most representative published randomized controlled trials in an attempt to explain the difference between observational and supplementation results. We found that this difference could be attributed to a variety of factors, namely: (i) study design (lack of a specific outcome in conjunction with timing of supplementation, enrolment of participants with heterogeneous vitamin D status); (ii) pitfalls in the interpretation of vitamin D equilibrium (lack of determination of plasma half-life); (iii) supplementation regimen (administration of a wide range of regimens, in terms of dose, bolus and form); (iv) geographical characteristics (vitamin D needs could vary significantly within a country, particularly in areas with a wide range of latitude gradient); (v) adaptations of vitamin D metabolism during pregnancy (vitamin D and calcium equilibrium are changed during pregnancy compared with the non-pregnant state) and (vi) supplementation of populations with low baseline 25(OH)D values would likely manifest beneficial effects. All these parameters should be taken into consideration in the design of future vitamin D supplementation trials.

Heat treatment enhances the antimicrobial activity of (+)-Catechin when combined with copper sulphate.

UNLABELLED: The aim of the study was to compare the antimicrobial activities of freshly made, heat-treated (HT) and 14 day stored (+)-Catechin solutions with (+)-catechin flavanol isomers in the presence of copper sulphate. (+)-Catechin activity was investigated when combined with different ratios of Cu(2+) ; 100°C heat treatment; autoclaving; and 14 day storage against Staphylococcus aureus. Cu(2+) -(+)-Catechin complexation, isomer structure-activity relationships, and H2 O2 generation were also investigated. Freshly made, HT, and 14 day stored flavanols showed no activity. While combined Cu(2+) -autoclaved (+)-Catechin and -HT(+)-Catechin activities were similar, HT(+)-Catechin was more active than either freshly made (+)-catechin (generating more H2 O2 ) or (-)-Epicatechin (though it generated less H2 O2 ) or 14 day-(+)-Catechin (which had similar activity to Cu(2+) controls-although it generated more H2 O2 ). When combined with Cu(2+) , in terms of rates of activity, HT(+)-Catechin was lower than (-)-Epigallocatechin gallate and greater than freshly made (+)-Catechin. Freshly made and HT(+)-Catechin formed acidic complexes with Cu(2+) as indicated by pH and UV-vis measurements although pH changes did not account for antimicrobial activity. Freshly made and HT(+)-Catechin both formed Cu(2+) complexes. The HT(+)-Catechin complex generated more H2 O2 which could explain its higher antimicrobial activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Natural products attract considerable attention in the search for novel antimicrobials, prebiotics and antioxidants. Enhanced biological activity of natural products has been demonstrated with chemical and heat treatment. This article extends the few publications on heat treatments of plant products and combinations with adjuncts, to raise antimicrobial activity against pathogens such as Staphylococcus aureus. We demonstrated that heat treatment could increase the activity of (+)-Catechin, a weak antimicrobial flavanol found commonly in plants in the presence of copper sulphate. Heat treatment of readily available resources merits consideration in the development of more potent substances for use in clinical settings and agriculture.

Maternal vitamin D status in pregnancy and offspring bone development: the unmet needs of vitamin D era.

Data from animal and human studies implicate maternal vitamin D deficiency during pregnancy as a significant risk factor for several adverse outcomes affecting maternal, fetal, and child health. The possible associations of maternal vitamin D status and offspring bone development comprise a significant public health issue. Evidence from randomized trials regarding maternal vitamin D supplementation for optimization of offspring bone mass is lacking. In the same field, data from observational studies suggest that vitamin D supplementation is not indicated. Conversely, supplementation studies provided evidence that vitamin D has beneficial effects on neonatal calcium homeostasis. Nevertheless, a series of issues, such as technical difficulties of current vitamin D assays and functional interplay among vitamin D analytes, prohibit arrival at safe conclusions. Future studies would benefit from adoption of a gold standard assay, which would unravel the functions of vitamin D analytes. This narrative review summarizes and discusses data from both observational and supplementation studies regarding maternal vitamin D status during pregnancy and offspring bone development.

Self-admitted behavior and perceived use of performance-enhancing vs psychoactive drugs among competitive athletes.

The relationships between projected use, self-reported behavior and attitudes to performance-enhancing (PED) and recreational (RD) drugs were investigated among 82 competitive Hungarian athletes, with 14.6% admitting using PED and 31.7% using RD. Both the observed doping estimations (even those made by non-users) and self-admitted use were considerably higher than the average rate of positive doping tests (2% of all tests). The notable overestimation by PED users (34.6% vs 16.9%) was in keeping with the false consensus effect. A prediction model with attitude and projection to the likelihood of PED use suggested at least a 70% chance of self-involvement of athletes, with responses at or above the median scores (Performance Enhancement Attitude Scale ≥ 60 and estimation ≥ 50%) on the two independent measures. Users overestimated the prevalence of doping in their sport (P=0.007) but not RD use, with the converse holding for RD users' views of doping (P=0.029). PED users also showed a significantly more lenient attitude toward doping (P<0.001). This domain-specific characteristic adds new information to the ongoing research effort in understanding drug-doping co-morbidity. The reasons for elevated in-group projection are discussed, along with the potential application of this phenomenon in doping epidemiology studies.

Popular drugs in sport: descriptive analysis of the enquiries made via the Drug Information Database (DID).

OBJECTIVE: To analyse enquiries made in the Drug Information Database (DID) to develop a better understanding of athletes' interests and concerns regarding the prohibited status of available substances. SETTING: Retrospective analyses of anonymous enquiries recorded in the DID in 2006 and 2007. PARTICIPANTS: Athletes and supporting personnel. RESULTS: The DID recorded 223 717 enquiries with 200 of the >6000 UK licensed pharmaceutical products receiving over 100 enquiries each. The majority (79.2%) of these enquiries were in the pharmaceutical product category, followed by recreational drugs (10.4%). A variety of common medications were subject to enquiry, with anti-inflammatory agents, decongestants and bronchodilators being most common; a trend in keeping with reported medication use by athletes. Of all enquiries, 42% were not found owing to misspelled words or enquiries about unregulated substances. The proportion of enquiries about substances not listed in the database is relatively high and has increased over the 24 month observation period. CONCLUSION: The DID is a well-used information resource with some 10 000 enquiries being made each month. Of the c. 60% of successful enquiries, the major focus was on pharmaceutical products. With some 73% of enquiries being made by the athletes themselves, further investigations are warranted to explore enquiry patterns in relation to specific sports. Of the unsuccessful enquiries, a large number were related to nutritional supplements, which warrants further investigation. The DID database appears to be a valid mirror of athletes' chemically assisted practices and may be successfully used to inform health professionals as well as antidoping prevention programmes.

Antimicrobial pomegranate rind extracts: enhancement by Cu(II) and vitamin C combinations against clinical isolates of Pseudomonas aeruginosa.

Recently, natural products have been further evaluated as sources of antimicrobial agents with efficacies against a variety of microorganisms. This study reports the antimicrobial activities of pomegranate rind extract (PRE) in combination with Fe(II) and Cu(II) salts against extended-spectrum multidrug-resistant Pseudomonas aeruginosa. Antimicrobial suspension assays were carried out using aqueous extract of pomegranate alone or in combination with metals salts against P. aeruginosa. The extract:metal salt combination was also enhanced with the addition of vitamin C. Marked activities were observed for the aqueous PRE/Cu(II) preparations, which were greatly enhanced by the addition of the reductant vitamin C. In contrast, the aqueous PRE/Fe(II) preparations were inactive, regardless of addition of vitamin C. The combination of PRE and Cu(II) salts and vitamin C showed the greatest activity against clinical isolates of P. aeruginosa. These results warrant further investigation of PRE as a potential source of new antimicrobial agents.

Health benefits and consequences of the Eastern Orthodox fasting in monks of Mount Athos: a cross-sectional study.

BACKGROUND/OBJECTIVES: Greek Orthodox fasting (OF), which involves 180-200 days of fasting per year, is dictated by the Christian Orthodox religion. For the first time, this cross-sectional study examines the characteristics and the effects of OF on anthropometry, cardiometabolic markers and calcium homeostasis in Athonian monks (AMs). SUBJECTS/METHODS: Daily intakes of energy, macro- and micronutrients of a day during a weekend of Nativity Fast, defined as non-restrictive day (NRD), and a weekday during Great Lent, labeled as restrictive day (RD) were recorded. RESULTS: The daily energy intake of 70 AM (age=38.8±9.7 years) was low during both RD and NRD (1265.9±84.5 vs 1660±81 kcal, respectively, P<0.001). Paired samples t-test showed statistically significant difference between daily intakes in RD and NRD: carbohydrates (159.6±21.8 vs 294.3±23.4 g, P<0.0001) and saturated fat (12.7±0.0 vs 16.4±0.0 g, P<0.0001) were lower, whereas protein (89.2±1.3 vs 72.35±1.3 g, P<0.001) was higher during RD. A subsample of 50 monks (age=38.7±10.6 years) formed a study cohort for cardiometabolic and calcium homeostasis assessment. Body weight (74.3±12.9 kg) and body mass index (BMI; 23.8±4.1 kg/m2) were independent of level of physical activity. Optimal profiles for lipid and glucose parameters (total cholesterol: 183.4±41.7 mg/dl, LDL: 120.6±37.6 mg/dl, triglycerides: 72.2±31.3 mg/dl, HDL: 48.5±14.2 mg/dl and homeostasis model assessment of insulin resistance (HOMA-IR) 1.02±0.40) were found. Profound hypovitaminosis D (8.8±6.2 ng/ml), high parathyroid hormone (PTH): 115.5±48.0 pg/ml with normal serum calcium levels (8.9±3.2 mg/dl) was observed. CONCLUSIONS: Unaffected by variation in lifestyle factors, the results of this unique study offers clear evidence for the health benefits of the strict Athonian OF through optimal lipid and glucose homeostasis.

Metal ion chelating peptides with superoxide dismutase activity.

The superoxide dismutase activities of two novel synthetic chelating peptides are reported. The peptides comprise a polyaminocarboxylic acid chelator (EDTA) conjugated to tyrosine (ET(1)) and phenylalanine (EP(1)). Superoxide dismutase (SOD) activity was exhibited for Cu(II) but not the Fe(III) complexes. The mimetic activities were compared to bovine erythrocyte SOD (3730 U/mg) and exhibited activities of 1119 U/mg for ET(1)-Cu(II) and 551 U/mg for EP(1)-Cu(II). Thus, small alterations in structure can have significant effects on the enzymatic activity of metallopeptides. These synthetic chelators have dual potential anti-inflammatory activity by chelating deleterious non-protein bound metal ions and concomitantly affording anti-oxidant mimetic activity.

Drug targeting to hypoxic tissue using self-inactivating bioreductive delivery systems.

Hypoxia is a characteristic feature of a number of diseases including some cancers, rheumatoid arthritis and diabetes. Hypoxic tissue facilitates the use of bioreductive drug targeting systems as oxygen suppresses the release of the active drug. This review focuses on bioreductive delivery where accompanying intramolecular cyclisation negates adduct formation between the bioreductive and macromolecules such as DNA. To date, three systems have been reported. In the quinone lactonization system, reduction of the quinone facilitates through bond cyclisation and concomitant release of the drug. In the self-alkylating system, a nucleophile is built into the bioreductive structure to favour intramolecular cyclisation over nucleophilic attack from DNA moieties. The final system is based on vitamin E which undergoes redox mediated cyclisation between its oxidised (tocopherol quionone) and reduced (tocopherol) forms. Self-inactivating bioreductive delivery systems represent a powerful tool for extending bioreductive-based drug delivery to non-cancerous hypoxic tissues.

Detection and investigation of the molecular nature of low-molecular-mass copper ions in isolated rheumatoid knee-joint synovial fluid.

Low-molecular-mass copper(II) species have been detected and quantified in ultrafiltrates (n = 7) of rheumatoid synovial fluid (SF) by a highly-sensitive HPLC-based assay system with the ability to determine Cu(II) concentrations of < 10(-7) mol.dm-3. High field 1H NMR spectroscopy demonstrated that addition of Cu(II)(aq.) to isolated samples of RA SF ultrafiltrates resulted in complexation by histidine > alanine > formate > threonine > lactate > tyrosine > phenylalanine, their effectiveness in this context being in the given order. CD spectra of Cu(II)-treated samples of intact SF exhibited absorption bands typical of copper(II)-albumin complexes, in addition to a band attributable to a low-molecular-mass histidinate complex (lambda min 610 nm). Since both albumin and histidine are potent radical scavengers, these results indicate that any .OH radical generated from bound copper ions will be 'site-specifically' scavenged. Hence, low-molecular-mass copper complexes with the ability to promote the generation of .OH radical which can then escape from the metal ion co-ordination sphere (and in turn, cause damage to critical biomolecules) appear to be absent from inflammatory SF.

A comparative evaluation of the metabolic profiles of normal and inflammatory knee-joint synovial fluids by high resolution proton NMR spectroscopy.

High resolution 1H NMR spectroscopy has been employed to investigate the metabolic profile of healthy human knee-joint synovial fluid (SF) and the biochemical data acquired have been compared with those of matched serum, and inflammatory knee-joint SF samples. Results obtained indicate that the healthy human knee-joint has a hypoxic status (high lactate level when expressed relative to that of paired serum) that is milder than that of the inflamed human knee-joint. Moreover, normal SF differs from that of inflammatory SF in that it contains little or no NMR-detectable lipoprotein-associated fatty acids and 'acute-phase' glycoproteins, an observation reflecting the limited passage of these macromolecules from plasma into the synovial space in healthy subjects.

An investigation of the abnormal metabolic status of synovial fluid from patients with rheumatoid arthritis by high field proton nuclear magnetic resonance spectroscopy.

The 1H Hahn spin-echo NMR profiles of rheumatoid synovial fluids have been investigated and compared with those of matched serum samples. In addition to markedly elevated lactate and diminished glucose concentrations, inflammatory synovial fluids contained (i) substantially lower levels of NMR-detectable chylomicron-and very-low-density-lipoprotein-associated triacylglycerols which appear to have a shortened mean chain-length, and (ii) high concentrations of ketone bodies (predominantly 3-D-hydroxybutyrate), relative to those of corresponding paired serum samples. These observations confirm the abnormal metabolic status of the inflamed rheumatoid joint and provide evidence for an increased utilisation of lipids for fuel therein.

Generation of substance P carbamate in neutral aqueous solution. Relevance to inflammatory joint diseases.

High-field proton (1H) nuclear magnetic resonance (NMR) spectroscopy has been employed to evaluate the formation of substance P carbamate in aqueous solution. Equilibration of substance P with physiologically relevant concentrations of bicarbonate (2.50 x 10(-2) mol.dm-3) at pH 7.00 generated a new multiplet signal centred at 4.13 ppm in its NMR spectrum, characteristic of the alpha-proton of peptide carbamate species. High-field 1H NMR spectroscopy also demonstrated that the model dipeptide, Arg-Gly, formed a carbamate in neutral aqueous solutions containing 2.50 x 10(-2) mol.dm-3 HCO3-. The physiological significance of these results is discussed in view of the central roles of vasoactive neuropeptides in human joint diseases and the hypercapnic environment of the inflamed rheumatoid joint.

Generation of lipid peroxidation products in culinary oils and fats during episodes of thermal stressing: a high field 1H NMR study.

The oxidative deterioration of glycerol-bound polyunsaturated fatty acids (PUFAs) in culinary oils and fats during episodes of heating associated with normal usage (30-90 min at 180 degrees C) has been monitored by high field 1H NMR spectroscopy. Thermal stressing of PUFA-rich culinary oils generated high levels of n-alkanals, trans-2-alkenals, alka-2,4-dienals and 4-hydroxy-trans-2-alkenals via decomposition of their conjugated hydroperoxydiene precursors, whereas only low concentrations of selected aldehydes were produced in oils with a low PUFA content, lard and dripping when subjected to the above heating episodes. Samples of repeatedly used, PUFA-rich culinary oils obtained from restaurants also contained high levels of each class of aldehyde. The dietary, physiological and toxicological ramifications of the results obtained are discussed.

Degradation of hyaluronate by Streptococcus intermedius strain UNS 35.

Streptococcus intermedius strain UNS 35, a brain abscess isolate, produced extracellular hyaluronidase when grown in brain heart infusion broth. Chemical assays with this enzyme indicated that hyaluronate depolymerisation resulted in the formation of carbohydrate moieties with N-acetylglucosamine at the reducing terminal and containing an unsaturated carbon-carbon double bond. The nature of the products of this hyaluronidase were investigated further by high-field (400 MHz) proton (1H) NMR spectroscopy. Treatment of hyaluronate with the enzyme resulted in a series of new, sharp resonances in spectra (acetamido methyl group singlets located at 2.03 and 2.07 ppm, sugar ring proton multiplets in the 3.5-4.2 ppm chemical shift range, and doublets at 5.16 and 5.87 ppm) characteristic of low-M(r) oligosaccharide species, predominantly those containing glucuronosyl residues with delta 4,5-carbon-carbon double bonds. Comparison of spectra acquired from hyaluronidase-treated samples with that of an authentic sample of 4-deoxy-L-threo-hex-4-enopyranosyluronic-acid-N-acetylglucosamine (delta UA GlcNAc) indicated that this disaccharide was a major product arising from the actions of this enzyme. When used in minimal media, hyaluronate supported growth of S. intermedius, with lactate as the major metabolic end-product.

An optical hydroxyl radical sensor.

A hydroxyl radical (.OH) fibre-optic sensor has been developed. An .OH radical-sensitive reagent phase (nitrophenol) was immobilized onto XAD-7 methacrylate beads. Subsequently the beads were attached to the distal end of a polymethylmethacrylate fibre optic. Nitrocatechol, generated from the attack of .OH radical on nitrophenol, exhibits a strong absorption band in the visible region of the electromagnetic spectrum (lambda max = 510 nm). Here, reflectance spectroscopy was employed to monitor the concomitant intensity decrease in the reflectance spectrum upon .OH radical attack. The sensor exhibited excellent stability and linearity of response to .OH generated by a Fenton reaction system (EDTA, Fe(II) and H2O2) with H2O2 over the concentration range of 3.6 x 10(-6)-8.0 x 10(-2) M.

When is a radical not a radical?

It is not commonly realised that symmetrical Fe(III) complexes are expected to have EPR spectra dominated by a symmetrical narrow line close to the free-spin g-value. The aim of this note is to stress that such features can be mistakenly identified as the spectra for stable organic radicals. This situation is a particular problem in studies of animal or plant tissue samples.

Detection of aldehydes and their conjugated hydroperoxydiene precursors in thermally-stressed culinary oils and fats: investigations using high resolution proton NMR spectroscopy.

High field (400 and 600 MHz) proton NMR spectroscopy has been employed to investigate the thermally-induced autoxidation of glycerol-bound polyunsaturated fatty acids present in intact culinary frying oils and fats. Heating of these materials at 180 degrees C for periods of 30, 60 and 90 min. generated a variety of peroxidation products, notably aldehydes (alkanals, trans-2-alkenals and alka-2,4-dienals) and their conjugated hydroperoxydiene precursors. Since such aldehydes appear to be absorbed into the systemic circulation from the gut in vivo, the toxicological significance of their production during standard frying practices is discussed.