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PubMed2006

Factors associated with the offering and sale of competitive foods and school lunch participation.

OBJECTIVE: The objective of this study was to identify factors that predict offering and sale of competitive foods, as well as factors that predict average daily participation in school lunch. DESIGN: Surveys were distributed to 271 school foodservice directors in a random sample of high schools in Pennsylvania that were selected to be representative of the entire population of high schools in Pennsylvania based on chosen demographic characteristics. SUBJECTS: Two hundred twenty-eight school foodservice directors (84%) returned surveys. STATISTICAL ANALYSES: Descriptive and multiple regression analyses were done using SPSS version 11.5 (2002, SPSS Inc, Chicago, IL). RESULTS: Percentage of students eligible for free or reduced-price meals and timing of lunch were significant predictors of a la carte sales. Enrollment was negatively associated with number of vending machines per student. The number of less nutritious food items offered in vending machines and existence of soft drink machines owned by soft drink companies, for which the school receives a percent of sales, both predicted number of vending machines per student. Enrollment was inversely related to average daily participation in school lunch. The percentage of students eligible for free/reduced-price meals and enforcement of a policy prohibiting parents or students from bringing food into the cafeteria from local fast-food establishments positively predicted average daily participation in school lunch. CONCLUSIONS: These findings may be useful to school wellness councils in developing wellness policies as mandated by the Child Nutrition and WIC Reauthorization Act of 2004, as well as in structuring school environments to promote more healthful food choices by students.

Adolescent↗
PubMed2004

Novel antibacterial agents for skin and skin structure infections.

UNLABELLED: With the continuing development of clinical drug resistance among bacteria and the advent of resistance to the recently released agents quinupristin-dalfopristin and linezolid, the need for new, effective agents to treat multidrug-resistant gram-positive infections remains important. With treatment options limited, it has become critical to identify antibiotics with novel mechanisms of activity. Several new drugs have emerged as possible therapeutic alternatives. This review focuses on agents newly introduced and those presently in clinical development for the treatment of skin and skin structure infections. Linezolid, quinupristin-dalfopristin, and daptomycin have been approved by the Food and Drug Administration for the treatment of skin and skin structure infections. Two newer compounds, oritavancin and dalbavancin, are in clinical development for this indication. In addition, the quinolones moxifloxacin and gatifloxacin recently were approved for cutaneous infections. LEARNING OBJECTIVE: At the conclusion of this learning activity, participants should be familiar with the modes of action, clinical indications, dosage regimens, and contraindications and cautions for several novel antibacterial agents for skin and skin structure infections.

Acetamides↗
PubMed1984

Modification of plant proteins by immobilized proteases.

A potential application of plant proteins could be a replacement of animal proteins now in use in the food industry on the basis of certain specific functional properties plant proteins have. Modification of the chemical structure of selected plant proteins is needed to replace more expensive animal proteins as food ingredients that have specific functional characteristics. Structure modification may be achieved by physical, chemical, or microbiological methods, or by a combination of these. Immobilized enzyme techniques offer significant advantages for protein modification. Knowledge of the molecular properties of plant proteins is essential to understand the basis of protein functionality, to modify proteins so that they acquire desirable functional properties, and to predict potential applications of modified plant proteins. This paper reviews all the above mentioned aspects of plant protein chemistry and potential utilization.

Amino Acids↗
PubMed2004

Effects of bridge shading on estuarine marsh benthic invertebrate community structure and function.

The effect of bridge shading on estuarine marsh food webs was assessed by comparing benthic invertebrate communities beneath seven highway bridges with marshes outside of bridge-affected areas (reference marshes). We used light attenuation and height-width ratio (HW ratio), which takes into account the two main bridge characteristics that determine the degree of shading, to quantify the impact of shading on invertebrate communities. Low bridges, with HW ratio <0.7 and light attenuation greater than 85-90%, had benthic invertebrate densities and diversity that were significantly lower than reference marshes. Density of benthic invertebrates at low bridges was 25-52% (29,685-72,920 organisms/m(2)) of densities measured in adjacent reference marshes (119,329-173,351 organisms/m(2)). Likewise, there were fewer taxa under low bridges (5.8/11.35 cm(2) core) as compared to the reference marshes (9.0/11.35 cm(2) core). Density of numerically dominant taxa (e.g., oligochaetes and nematodes) as well as surface- and subsurface deposit feeders also were reduced under low bridges. Decreased invertebrate density, diversity, dominant taxa, and alterations of trophic feeding groups beneath low bridges was correlated with diminished above- and below-ground macrophyte biomass that presumably resulted in fewer food resources and available refuges from predators. With a greater knowledge of bridge shading effects, bridge construction and design may be improved to reduce the impacts on estuarine benthic invertebrate communities and overall ecosystem structure and function.

Animals↗
PubMed1984

'These are modern times': infant feeding practice in Peninsular Malaysia.

Traditionally, Malaysian women (Malay, Indian and Chinese) breastfed their infants as a matter of course and for an extended period of time; only elite Chinese women might have resorted to a wet-nurse. But the introduction of condensed and dehydrated milk in colonial Malaya from the late nineteenth century, and the later marketing also of commercially manufactured baby foods, led to some variation in traditional practice. Structural changes, industrialiZation and urbanisation affected social as well as economic life, and again these broad changes had an impact on infant feeding. Today, few women remain unfamiliar with the wide range of infant food products sold in the most isolated provision shops. This paper focuses on key sociological factors that might predict the frequency and duration of breastfeeding and weaning patterns. The data analysed below, collected during semi-structured interviews with 278 women presenting at Maternal and Child Health Clinics in Peninsular Malaysia, are in part confusing. They suggest that the women most likely to bottle feed only or to breast feed for a short period, and to use commercial baby foods, are young, with one child only, who reside in urban or peri-urban areas and have a reasonable household income. Higher educated women, and women whose husbands are in non-traditional occupations, are also less likely to breast feed or to do so for an extended period. But the profile of infant feeding practices is by no means clear. One of the shortcomings of the study relates to the method of collection of data, and highlights the need for detailed ethnographic studies to better explore the variability and complexity of the patterns of infant feeding.

Bottle Feeding↗
PubMed2006

Asymmetries in specialization in ant-plant mutualistic networks.

Mutualistic networks involving plants and their pollinators or frugivores have been shown recently to exhibit a particular asymmetrical organization of interactions among species called nestedness: a core of reciprocal generalists accompanied by specialist species that interact almost exclusively with generalists. This structure contrasts with compartmentalized assemblage structures that have been verified in antagonistic food webs. Here we evaluated whether nestedness is a property of another type of mutualism-the interactions between ants and extrafloral nectary-bearing plants--and whether species richness may lead to differences in degree of nestedness among biological communities. We investigated network structure in four communities in Mexico. Nested patterns in ant-plant networks were very similar to those previously reported for pollination and frugivore systems, indicating that this form of asymmetry in specialization is a common feature of mutualisms between free-living species, but not always present in species-poor systems. Other ecological factors also appeared to contribute to the nested asymmetry in specialization, because some assemblages showed more extreme asymmetry than others even when species richness was held constant. Our results support a promising approach for the development of multispecies coevolutionary theory, leading to the idea that specialization may coevolve in different but simple ways in antagonistic and mutualistic assemblages.

Adaptation, Physiological↗
PubMed2001

Increased plasma methylmalonic acid level does not predict clinical manifestations of vitamin B12 deficiency.

BACKGROUND: The prevalence of vitamin B(12) deficiency, defined as an elevated concentration of plasma methylmalonic acid (P-MMA), has been estimated to be 15% to 44% in the elderly. However, we do not know whether an increased P-MMA level actually indicates or predicts a clinical condition in need of treatment. PARTICIPANTS AND METHODS: In a follow-up study, 432 individuals not treated with vitamin B(12) were examined 1.0 to 3.9 years after initial observation of an increased P-MMA concentration (>0.28 micromol/L). The examination included laboratory tests, a structured interview to disclose symptoms, a food frequency questionnaire, and a clinical examination including a Neurological Disability Score. RESULTS: Variation in P-MMA levels over time was high (coefficient of variation, 34%). In only 16% of participants, P-MMA levels increased substantially, whereas 44% showed a decrease. Level of P-MMA was significantly but not strongly associated with levels of plasma cobalamins (r = -0.22, P<.001) and plasma total homocysteine (r = 0.37, P<.001). After adjustment for age and sex, we found no associations between P-MMA concentration and the total symptom score (P =.61), the total Neurological Disability Score (P =.64), or other clinical manifestations related to vitamin B(12) deficiency. CONCLUSIONS: An increased level of P-MMA did not predict a further increase with time and clinical manifestations related to vitamin B(12) deficiency. We therefore challenge the use of an increased P-MMA concentration as the only marker for diagnosis of vitamin B(12) deficiency.

Adolescent↗
PubMed1992

Positional behavior and body size of arboreal primates: a theoretical framework for field studies and an illustration of its application.

The rationale for most field studies of the positional behavior of arboreal primates has been the need to document natural behaviors quantitatively in order to infer the functional significance of morphological configurations. This focus on interactions of morphology with behavior is justifiable, but there exists another important level of biological relationships, that of the animal with its structural habitat, which it must negotiate to find food and avoid being preyed on. Recently it has become apparent that body size is likely to affect relationships of positional behavior with habitat structure, as well as with morphology. Here I offer a framework for research on functional relationships of positional behavior, body size, and habitat structure, with the ultimate objective of elucidating the aptive significance of the great diversity exhibited by arboreal primates. This approach specifies several distinct problems that animals solve, and indicates how research might be directed at revealing the relative effectiveness with which different primates solve them. A preliminary application of the framework examines sympatric north Sumatran primates.

Animals↗
PubMed2005

Unconventional method based on circular dichroism to detect peanut DNA in food by means of a PNA probe and a cyanine dye.

In this paper we report an innovative and unconventional method based on circular dichroism for the identification of peanut DNA in food, which can be detected after PCR amplification at the nanomolar level by using an achiral PNA probe complementary to a tract of the peanut Ara h 2 gene and an achiral 3,3'-diethylthiadicarbocyanine dye [DiSC(2)(5)]. Peanuts are one of the most common causes of severe allergic reactions to foods and are particularly dangerous when they are "hidden" (undeclared) in food. For better protection of consumers, detection methods are required to specifically detect the presence of hidden allergens in a wide variety of food items. Alternative to the detection of the proteins is the determination of species-specific DNA, which is more resistant to technological treatments. PNAs are very specific probes able to recognize DNA sequences with high affinity and evidence for the binding can be obtained by using the DiSC(2)(5) dye, which aggregates onto the PNA-DNA duplex giving rise to a characteristic visibile band at 540 nm. Because the PNA-DNA duplex is in a right-handed helical conformation, the aggregation of the dye to the duplex gives also rise to a strong CD signal in the 500-600 nm region with a strong exciton coupling due to the formation of multimeric species, since the handedness of the helix is transferred to the dye aggregate. The dye does not interact with the free single-stranded DNA and although aggregating on the achiral PNA, this interaction is obviously not detectable by circular dichroism. Thus, only the formation of the PNA-DNA duplex, which takes place only upon specific Watson-Crick hydrogen binding between the PNA and the DNA bases, is detected, ensuring a very high specificity and sensitivity. The method has been optimized in a model system by using a synthetic oligonucleotide complementary to the PNA probe, showing that the intensity of the signal is linearly related to the amount of the DNA. The optimized method has been applied to the identification and quantitation of DNA extracted and amplified by PCR from peanuts and from peanut-containing foods, allowing for a very sensitive detection at a very low level (few pmol).

Arachis↗
PubMed2003

Liquid chromatographic/electrospray ionization mass spectrometric studies of proanthocyanidins in foods.

The proanthocyanidins in three foods (pinto beans, plums and cinnamon) were studied with electrospray ionization (ESI) mass spectrometry (MS) in the negative mode following separation by normal-phase high-performance liquid chromatography. The MS/MS analysis demonstrated that the major ions derived from heterocyclic ring fission and retro-Diels-Alder reaction of flavan-3-ol provided information about the hydroxylation pattern and type of interflavan bond. The connection sequence of the oligomers was identified through diagnostic ions derived from quinone methide (QM) cleavage of the interflavan bond. Novel heterogeneous B-type proanthocyanidins containing (epi)afzelechin as subunits were identified in pinto beans. Proanthocyanidins with interestingly different A-type linkages were identified in plums and cinnamon. In efforts aimed at extending the identification capacity of ESI-MS to polymers, we found that the polymeric procyanidins fragmented readily instead of forming multiply charged ions in the negative ESI mode. Fragmentation patterns were proposed based on our data obtained by ESI-MS/MS and ESI time-of-flight MS.

Chromatography, Liquid↗
PubMed2005

Electrospray[+] tandem quadrupole mass spectrometry in the elucidation of ergot alkaloids chromatographed by HPLC: screening of grass or forage samples for novel toxic compounds.

Ergot alkaloids are mycotoxins generated by grass and grain pathogens such as Claviceps, for example. Ergot alkaloid-poisoning syndromes, such as tall fescue toxicosis from endophyte-infected tall fescue grass, are important veterinary problems for cattle, horses, sheep, pigs and chickens, with consequent impact on food, meat and dairy industries. Damage to livestock is of the order of a billion dollars a year in the United States alone. HPLC with UV and fluorescence detection are the predominant means of ergot alkaloid determination, with focus on quantitation of the marker compound ergovaline, although ELISA methods are undergoing investigation. These techniques are excellent for rapid detection, but of poor specificity in defining new or poorly characterized ergot alkaloids and related compounds. This paper demonstrates the facility of using electrospray(+) mass spectrometry with multiple reaction monitoring (MRM) detection during chromatographic examination of ergot alkaloid standards of lysergic acid, lysergol, ergonovine, ergovaline, ergotamine, ergocornine, ergocryptine and ergocrystine by HPLC. Ergoline-8 position epimers could be separated on the gradient HPLC system for ergocornine, ergocrystine and ergonovine and appeared as shoulders for ergotamine and ergovaline; epimers generally showed different patterns of relative intensity for specific MRM transitions. There was reasonable correspondence between retention of standards on the 2-mm ESI(+)MS phenyl-hexyl-based reverse phase column and those on the 4-mm C18-based column. Since up to 10% of clinical cases involving toxin exposure display unidentified chromatographic peaks, 11 samples of feed components associated with such cases were studied with developed MRM methods to attempt elucidation of crucial components if possible. Ergotamine appeared in all, ergovaline appeared in five and ergocornine appeared in six; ergonovine, ergocryptine, ergocrystine and lysergol also appeared in several. In addition, molecular weights of compounds newly revealed by mass spectrometry suggested ergosine, ergostine and ergoptine in four samples, for which standards were not available. Dehydrated products of ergotamine, ergocrystine and ergocornine were discovered, along with dihydrogenated ergocrystine and ergocryptine in seven of the samples, and the issue was raised as to whether dehydration was strictly an instrument-derived artifact. Finally, five of the samples, along with fescue seed standard, evidenced one or more of 14 new ergot alkaloids ranging in size from 381 to 611 molecular weight and with key mass spectral characteristics of ergot alkaloids, specifically the pair of peaks m/z 223 and 208, corresponding to the ergoline ring system and its demethylated variant, respectively. It is anticipated that findings such as these will provide impetus to future development of analytical methodology for these heretofore relatively rare ergot alkaloid species.

Animal Feed↗
PubMed2004

Fast screening method for the analysis of total flavonoid content in plants and foodstuffs by high-performance liquid chromatography/electrospray ionization time-of-flight mass spectrometry with polarity switching.

A liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) method based on time-of-flight (TOF) MS with polarity switching and continuous exact mass measurement using a LockSpray ion source was developed for fast evaluation of the total flavonoid content in plants and foodstuffs. No complicated sample preparation was needed, but only a dilution of the extracts. A fast generic gradient elution and wide mass range acquisition was used with good sensitivity. The total analysis time was only 23 min. The ion chromatograms for flavonoid compounds were automatically extracted, and the fragmentation patterns obtained using positive ion mode and exact mass data for both polarities were used for the tentative identification of compounds. Software-based automated searching of molecular ions for flavonoids and their glycosides (xylosides/arabinosides, rhamnosides, glucosides/galactosides) from total ion chromatograms was used. The compounds were quantified using quercetin, quercitrin, rutin and kuromanine as external standards and dextromethorphan as an internal standard. The detection limits ranged from 0.01-0.04 microg/mL, while the quantitation ranges obtained were 0.2-10 microg/mL for anthocyanins and 0.2-4 microg/mL for the other flavonoids. The accuracies within these ranges varied between 80-120% and precision was in the range 0-14% (relative standard deviation). Flavonoid contents of two medicinal plants (Hypericum perforatum and Rhodiola rosea), two grape red wines, two orange juices and two green teas were evaluated using the method, and the results obtained were in good agreement with those published previously.

Calibration↗
PubMed2006

Mass spectral characterization of ergot alkaloids by electrospray ionization, hydrogen/deuterium exchange, and multiple stage mass spectrometry: Usefulness of precursor ion scan experiments.

Six ergot alkaloids belonging to the lysergic acid derivatives (ergonovine (EGN) and methysergide hydrogen maleinate (MHM)) and peptide-type derivatives (ergocristine (EGR), ergotamine (EGT), ergocornine (EGC) and alpha-ergokryptine (EGK)) were studied by positive electrospray tandem mass spectrometry. The fragmentation mechanisms of these compounds were studied by collision-induced dissociation (CID) using triple quadrupole and ion trap mass spectrometers, and the nature of the major product ions further confirmed by hydrogen/deuterium (H/D) exchange experiments. A common abundant product ion at m/z 223 was characteristic of the two classes of ergot alkaloids. Therefore, a precursor ion scan of m/z 223 that triggers information data acquisition (IDA) in combination with CID experiments was used to identify other potential ergot alkaloids. Using this approach, it was possible to confirm the presence of ergosine, another peptide-type ergot alkaloid, in a rye flour extract at trace levels.

Deuterium↗
PubMed1998

Flavonoids in foods as in vitro and in vivo antioxidants.

The polyphenol antioxidants in foods and beverages are shown to be powerful in vitro antioxidants. The polyphenols in foods and beverages enrich low density lipoproteins and decrease their oxidizability ex vivo after spiking and in vivo after absorption of the polyphenols following ingestion of beverages. These studies provide mechanisms to explain the epidemiological study which shows that consumption of fruits, vegetables and beverages reduce the risk of cardiovascular and cerebrovascular disease.

Animals↗
PubMed2004

Annual patterns in bacterioplankton community variability in a humic lake.

Bacterioplankton community composition (BCC) was monitored in a shallow humic lake in northern Wisconsin, USA, over 3 years using automated ribosomal intergenic spacer analysis (ARISA). Comparison of ARISA profiles of bacterial communities over time indicated that BCC was highly variable on a seasonal and annual scale. Nonmetric multidimensional scaling (MDS) analysis indicated little similarity in BCC from year to year. Nevertheless, annual patterns in bacterioplankton community diversity were observed. Trends in bacterioplankton community diversity were correlated to annual patterns in community succession observed for phytoplankton and zooplankton populations, consistent with the notion that food web interactions affect bacterioplankton community structure in this humic lake. Bacterioplankton communities experience a dramatic drop in richness and abundance each year in early summer, concurrent with an increase in the abundance of both mixotrophic and heterotrophic flagellates. A second drop in richness, but not abundance, is observed each year in late summer, coinciding with an intense bloom of the nonphagotrophic dinoflagellate Peridinium limbatum. A relationship between bacterial community composition, size, and abundance and the population dynamics of Daphnia was also observed. The noted synchrony between these major population and species shifts suggests that linkages across trophic levels play a role in determining the annual time course of events for the microbial and metazoan components of the plankton.

Bacterial Physiological Phenomena↗
PubMed2001

Effects of Additions of DOC on Pelagic Biota in a Clearwater System: Results from a Whole Lake Experiment in Northern Sweden.

An oligotrophic clearwater lake, initially characterized by a pronounced dominance of autotrophic phytoplankton and mostly by one species, the green alga Botryococcus, was subject to additions of dissolved organic carbon in the form of white sugar (sucrose) during two consecutive years. The hypothesis tested was that it is organic carbon per se, and not other possible effects of humic substances, that determines the differences in structure of the planktonic ecosystem between humic and clearwater lakes. The additions of DOC resulted in a significant increase in bacterial biomass and a decrease in the biomass of autotrophic phytoplankton. The biomass of mixotrophic and heterotrophic flagellates instead increased significantly, whereas no effects were found to propagate to higher trophic levels. As a result of the changes among biota, total planktonic biomass also decreased to a level typical of nearby humic lakes. We suggest that it is the carbon component of humic material and its utilization by bacterioplankton that determines the structure and function of the pelagic food web in humic lakes.

Journal Article↗
PubMed2005

Norharman-induced motoric impairment in mice: neurodegeneration and glial activation in substantia nigra.

The beta-carboline norharman is present in cooked food and tobacco smoke and show structural resemblance to the neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. C57BL/6 mice were injected subcutaneously with norharman (3 and 10 mg/kg) twice per day for five consecutive days. Eighteen hours after the last dose an increased expression of glial fibrillary acidic protein and fluoro-jade staining were demonstrated whereas the number of tyrosine hydroxylase positive cells were unchanged in the substantia nigra. Two weeks after the last treatment a decreased motor activity was observed whereas cognitive functions remained intact. In cultured PC12 cells norharman treatment induced mitochondrial dysfunction and increased the number of caspase-3 and TUNEL-positive cells. The results demonstrate that norharman induced apoptosis in cultured cells as well as early neurodegeneration, glial activation and sustained motor deficits in mice and suggest that exposure to norharman may contribute to idiopathic Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗