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PubMed2000

Epidemiology and ecology of enterococci, with special reference to antibiotic resistant strains, in animals, humans and the environment. Example of an ongoing project within the European research programme.

The objectives of the present study are to generate knowledge of the ecology and epidemiology of enterococci in the food chain by studying the following: (1) the population structure (in measures of abundance, number of vancomycin resistant strains, antibiotic resistance patterns, diversity, and stability) among enterococcal populations in different geographical regions and in different links of the food chain (2) possible transmission of strains through the food chain and between hospital environments and the food chain (3) the association between vancomycin resistance and individual strains of enterococci and (4) the diversity of the drug resistance genes in enterococci. So far, 1578 samples have been collected from different countries within the EU (Sweden, Denmark, UK and Spain), and from different habitats (pig farms, carcasses in slaughter houses, soil, manure, water, sewage, and humans). Total and vancomycin resistant enterococcal populations in each sample have been enumerated and more than 12000 isolates have been characterised by phenotyping. Representative isolates are further species identified and characterised by genotyping and MIC determination and from antibiotic resistant isolates the resistance genes are characterised.

Animals↗

PubMed2004

Mass spectrometric studies on the intrinsic stability of destruxin E from Metarhizium anisopliae.

Destruxins are of current interest as bioactive agents. They are cyclic hexadepsipeptides produced by fungi, the most common destruxins, A, B and E, differing in the structure of a side chain. Before they can be widely used, the potential risk of destruxins and their metabolites entering the human food chain must to be assessed; thus, knowledge of the structures of their degradation products is essential. Here we report a study aimed at identifying, by tandem mass spectrometry and accurate mass analysis, the products resulting from thermally and temporally induced degradation of destruxin E. The degradation products fell into two groups: those with relatively simple modifications of the side chain and those involving much more complex rearrangements. The structures of most of the degradation products were deduced from the MS data, with the major product being destruxin E diol: significantly, this compound had previously been reported to have only been produced as a metabolic product of enzyme action rather than as a simple degradation product as demonstrated here.

Ascomycota↗

PubMed1993

Structural basis of the mutagenicity of heterocyclic amines formed during the cooking processes.

A data base consisting of 61 heterocyclic amines formed during food preparation and their des-amino analogs were subjected to structure-activity analysis using the CASE method, a structural activity relational expert system. The program identified the major structural determinants associated with mutagenic activity or lack thereof. The structures identified as contributing to the probability of activity as well as those associated with mutagenic potency were highly predictive of molecules not in the learning set. The major structural determinant, the aromatic amino moiety, and quantum mechanical calculations revealed that the mutagenic potency associated with this functionality derived from their contribution to the energy of the Lowest Unoccupied Molecular Orbital (LUMO).

Amines↗

PubMed1976

Changing patterns of professional education in colleges and universities--1964 and 1974. Survey in the North Atlantic Region.

This report concerns two surveys of undergraduate nutrition education in a selected group of degree-granting institutions within the North Atlantic Region of the United States. The purpose of the surveys was to determine the status of nutrition teaching in the early 1960s and the direction of change during the intervening ten-year period (1974). Reviews of the literature and college catalogues, personal interivews, letters of inquiry, and questionaires formed the basis for study. The last decade has witnessed change in organizational arrangement and in the number of programs offering major concentrations in foods, nutrition, and dietetics. Of these, twelve units in the Region studied are now engaged in coordinated programming. There has been a 125 per cent increase in foods and nutrition faculty. All but seventeen of the 275 faculty appear in programs approved by The American Dietetic Association. Basic questions about undergraduate education in foods and nutrition and the most desirable administrative structure for this specialization will continue through the 1970s. Solutions will undoubtedly be forthcoming after further experimentation and evaluative research.

Allied Health Personnel↗

PubMed2004

Modification of zearalenone structure in model and natural conditions.

Zearalenone is a mycotoxin widely occurring in cereals and animal feed, and it is associated with hyperestrogenism and other reprodutive disorders in animals. A new method of detoxication of feedstuffs involves alkaline hydrolysis of toxic macrolactone (1) (as well as model compounds (2a, 2b)). The method caused modification of zearalenone structure under mild conditions and the toxin underwent irreversible hydrolysis with high efficiency.

Animal Feed↗

PubMed2006

Selective serotonin reuptake inhibitor (fluoxetine) decreases the effects of ghrelin on memory retention and food intake.

Ghrelin (Ghr) is an appetite stimulating hormone that is produced peripherally, by the stomach, and centrally as well. Previous investigations show that Ghr increases food intake and memory retention in rats, and that extra-hypothalamic structures, such as the hippocampus, participate in these effects. In the present work we analyzed the effect on food intake and memory retention induced by Ghr after serotonin (5-HT) availability modification at the serotoninergic synapses. Animals only treated with a selective serotonin reuptake inhibitor (SSRI), fluoxetine (FLU) 5 mg/kg or clomipramine (CLO) 2.5 and 5 mg/kg, showed a significant reduction in both food intake and memory retention. On the contrary, Ghr administration induces a significant increase in food intake and a dose-dependent increase in short and long term memory retention. When the animals were treated with FLU prior to Ghr injection, the food intake induced, as well as the expression of short and long term memory retention, was decreased. In conclusion, evidence presented in this paper suggests that the effects of Ghr on both feeding and memory retention in extra-hypothalamic structures such as the hippocampus, could depend on the availability of 5-HT.

Animals↗

PubMed1993

Two types of motivation revealed by ibotenic acid nucleus accumbens lesions: dissociation of food carrying and hoarding and the role of primary and incentive motivation.

Rats with dopamine-depleting lesions of the nucleus accumbens (NAcc) no longer carry food and leave it in a refuge (carry-to-leave or hoard). The present study replicates this finding and extends it to rats with ibotenic acid lesions. The same rats, however, were found to carry food to a refuge to eat it (carry-to-eat). Thus, within a test session, control rats would first carry food to eat it, and when sated, carry the remaining food to leave it in the refuge. NAcc food-deprived rats carried food to eat it but when sated engaged mainly in exploratory behavior. When carrying-to-eat, NAcc rats modulated responses normally to food size and eating time, their movement speed and motor patterns were normal, and their eating times were normal. Nevertheless, they were slower to return for food after eating, and they did not show normal slowing of eating times with successively presented food pellets. The failure of NAcc rats to carry-to-leave when sated was not related to general inactivity. In activity tests, they were as active in the light, more active in the dark, and did not differ from control rats under amphetamine (1.25 and 2.5 mg/kg). Their impairments were also not related to damage to other forebrain related structures, as they displayed normal neocortical and hippocampal atropine-sensitive and atropine-resistant electroencephalograms (EEG). The finding that NAcc rats carry-to-eat when hungry but do not carry-to-leave when sated suggests two separate conclusions. First, food carrying can be dissociated into two separate actions with respect to neural control, carrying-to-eat and carrying-to-leave. Second, the selective involvement of the NAcc in only carrying-to-leave suggests that it is associated with recruiting actions in response to the secondary incentive features of food but is not required for behaviors associated with food consumption. Other structures are presumably activated by the primary drive-reducing features of food. The results are discussed in relation to two-factor theories of motivation.

Animals↗

PubMed2004

Water sorption properties of extruded zein films.

Water interactions in extruded zein films were investigated through moisture sorption isotherms. Sorption isotherms of zein products were affected by composition and structure morphology. Zein powder showed moisture sorption hysteresis, which was not observed in extruded samples. Extruded samples held less moisture than zein powder, while films containing oleic acid showed further reduction in moisture uptake. Brunauer, Emmett, and Teller (BET) and Guggenheim, Anderson, and De Boer (GAB) models fitted well the moisture sorption isotherms of zein products. Monolayer values estimated by BET and GAB models were consistent with predictions based on zein structural models. Water vapor permeability (WVP) of zein films was affected by the relative humidity of testing environment. Higher relative humidity resulted in higher WVP.

Absorption↗

PubMed2006

The short neuropeptide F-like receptor from the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae).

In invertebrates, neuropeptide F (NPF) peptides share structural similarity with vertebrate neuropeptide Y, which regulates food consumption, circadian rhythms, anxiety, and other physiological processes. The insect neuropeptide F receptors belong to the G protein-coupled receptor (GPCR) rhodopsin family. We have cloned the fire ant putative short NPF receptor using PCR and RACE methods. The complete 2,185-bp cDNA encodes a 387-residue protein with a predicted GPCR seven transmembrane region structure. We propose that the sequence of the honey bee short NPF receptor, which has not yet been annotated, encodes a protein of 393 residues. In fire ant mated queens, receptor transcripts were detected in the brain, midgut, hindgut, Malpighian tubules, fat body, and ovaries. The highest transcriptional expression was found in the brain. The downregulation of the fire ant short NPF receptor transcriptional expression in the brain with starvation suggests that the short NPF signal transduction cascade may play a role in feeding regulation in fire ant mated queens.

Amino Acid Sequence↗

PubMed2000

Ecosystem size determines food-chain length in lakes.

Food-chain length is an important characteristic of ecological communities: it influences community structure, ecosystem functions and contaminant concentrations in top predators. Since Elton first noted that food-chain length was variable among natural systems, ecologists have considered many explanatory hypotheses, but few are supported by empirical evidence. Here we test three hypotheses that predict food-chain length to be determined by productivity alone (productivity hypothesis), ecosystem size alone (ecosystem-size hypothesis) or a combination of productivity and ecosystem size (productive-space hypothesis). The productivity and productive-space hypotheses propose that food-chain length should increase with increasing resource availability; however, the productivity hypothesis does not include ecosystem size as a determinant of resource availability. The ecosystem-size hypothesis is based on the relationship between ecosystem size and species diversity, habitat availability and habitat heterogeneity. We find that food-chain length increases with ecosystem size, but that the length of the food chain is not related to productivity. Our results support the hypothesis that ecosystem size, and not resource availability, determines food-chain length in these natural ecosystems.

Animals↗

PubMedDate not supplied

Brain tumors and anorexia nervosa syndrome.

This review presents 21 cases, found in the literature, of a CNS lesion (a tumor in 19 of them) associated with emaciation, anorexia and several psychic symptoms that had led to the diagnosis of anorexia nervosa (AN). Anorexia and psychic disturbances preceded the neurologic signs and/or the correct diagnosis in all patients (by a mean of 2.9 years, range = 0.2-17 years). Anorexia had begun before the age of 25 years in 18 patients of which two-thirds were females. Only a few cases fulfilled the DSM-III-R criteria for AN; the majority could be characterized as 'atypical AN'. Although AN is usually conceived as a primarily psychogenic disorder, structural lesions of the hypothalamus (or other sites involved in food regulation) in animal models and in these human cases mimic many features of AN, suggesting the possibility of an as yet unidentified structural hypothalamic disorder to be implicated in the etiopathogeny of AN. The unusually high incidence of germ-cell tumors in this review (33%) suggests that they are more likely than other tumors to influence the limbic system toward an anorectic syndrome.

Adolescent↗

PubMed2005

Dietary proanthocyanidins: occurrence, dietary intake, bioavailability, and protection against cardiovascular disease.

The French have one of the lowest incidences of coronary heart disease in the Western world despite a diet with a relatively high fat content. This phenomenon that has puzzled researchers worldwide for more than a decade is known as the 'French paradox' and has been linked to the high consumption of red wine in France. Red wine is rich in the complex polyphenols, the proanthocyanidins, and these compounds have recently attracted attention as potential cardiac-protective compounds. The present review summarizes the literature on proanthocyanidins with focus on their chemical structure, the occurrence, the daily intake from foods, the bioavailability and metabolism, and the evidence for a protective effect against cardiovascular diseases.

Animals↗

PubMed2005

Five years of research on health risks and benefits of Maillard reaction products: an update.

When the COST Action 919 started to investigate the role of melanoidins in food and health in 1999, the chemical structures of dietary melanoidins were poorly defined and hardly anything was known about structure-specific health effects of this chemical class. In addition, the degradation of melanoidins in the gut and their absorption and function or that of any of their degradation products had not yet been reported. In the past five years, results from in vitro studies demonstrated that at least some of the dietary melanoidins are degraded by intestinal microorganisms, possibly influencing their growth rate. The absorption and excretion rates of individual Maillard reaction compounds and melanoidin structures have been investigated in animal studies. These studies show that at least 30% of the ingested dose of low-molecular-weight compounds are absorbed. Structure-specific health-promoting effects of newly identified compounds have been described by means of their antioxidant and chemopreventive activity in cell culture investigations as well as in animal feeding studies and human trials. Harmful effects of dietary melanoidins have been investigated in the context of their ability to promote glycation reactions in vivo, which are involved in the progression of several diseases, such as diabetes mellitus, cardiovascular complications, and Alzheimer's disease. Toxicological studies were performed showing that melanoidin structures can not be classified as potent dietary mutagens or genotoxins. Thus, substantial knowledge on the health effects of melanoidins has been gained within COST Action 919. But still, further studies are needed to distinguish between chemically identified harmful and health-beneficial melanoidins.

Antioxidants↗

PubMed1999

From regional ethnographies to interdisciplinary approaches-research on meals in Finland.

The paper reviews Finnish research on meals and meal patterns since the turn of the century. The main research traditions and cases representing various methodological approaches-qualitative interview, health behaviour questionnaire and dietary survey-are discussed. In line with studies undertaken in other industrialized countries, the Finnish studies show that meal patterns are related to socio-economic structure, work schedules, lifecourse, living conditions and food availability. Meal patterns vary by individual energy needs, and the nutrient contents of meals can be different from those of snacks. It is difficult to account for all determinants and characteristics of meals in a single study. The three cases shed light on the various aspects of the meal. When planning an empirical study on meals the researcher should ask herself/himself at least four questions: (1) who defines the meal?; (2) are meal patterns assumed to vary by time and between subgroups of the study population?; (3) is information on nutrient content of various eating occasions relevant to the study?; and (4) could information on meals be obtained from existing data sources?

Cultural Characteristics↗

PubMed2006

Age at introduction of new foods and advanced beta cell autoimmunity in young children with HLA-conferred susceptibility to type 1 diabetes.

AIMS/HYPOTHESIS: Evidence for the role of infant feeding in the development of beta cell autoimmunity is inconsistent. We set out to study the effects of breastfeeding and of age at introduction of supplementary foods on the development of beta cell autoimmunity. SUBJECTS AND METHODS: A prospective birth cohort of 3,565 infants with HLA-DQB1-conferred susceptibility to type 1 diabetes was recruited between 1996 and 2001 from two university hospital areas in Finland. Blood samples were collected at 3- to 12-month intervals to measure antibodies against islet cells, insulin, glutamate dehydroxylase and islet antigen 2. The families kept a record on the age at introduction of new foods, and for each visit completed a structured dietary questionnaire. The endpoint was repeated positivity for islet cell antibodies together with at least one of the other three antibodies. RESULTS: The overall or exclusive duration of breastfeeding was not associated with the risk of developing the endpoint. An early age at introduction of fruits and berries (< or =4 months) was related to increased risk of developing positivity for the endpoint (hazard ratio [95% CI] for earliest tertile 2.02 [1.03-3.95] and for midtertile 1.97 [1.06-3.64] compared with latest tertile >4 months). Also, introducing roots between 3 and 3.9 months (midtertile) was related to increased risk of the endpoint (hazard ratio [95% CI] for the earliest tertile 1.04 [0.57-1.90] and for midtertile 1.82 [1.19-2.79] compared with latest tertile). These associations were independent of several putative socio-demographic and perinatal confounding factors. CONCLUSIONS/INTERPRETATION: Our findings suggest that an early age at introduction of fruits and berries and roots associates independently with beta cell autoimmunity, contradicting earlier findings from smaller birth cohort studies.

Age Factors↗

PubMed2003

Ungulate community structure and ecological processes: body size, hoof area and trampling in African savannas.

A wide range of bioenergetic, production, life history and ecological traits scale with body size in vertebrates. However, the consequences of differences in community body-size structure for ecological processes have not been explored. We studied the scaling relationships between body mass, shoulder height, hoof area, stride length and daily ranging distance in African ungulates ranging in size from the 5 kg dik-dik to the 5,000 kg African elephant, and the implications of these relationships on the area trampled by single and multispecies herbivore communities of differing structure. Hoof area, shoulder height and stride length were strongly correlated with body mass (Pearson's r >0.98, 0.95 and 0.90, respectively). Hoof area scaled linearly to body mass with a slope of unity, implying that the pressures exerted on the ground per unit area by a small antelope and an elephant are identical. Shoulder height and stride length scaled to body mass with similar slopes of 0.32 and 0.26, respectively; larger herbivores have relatively shorter legs and take relatively shorter steps than small herbivores, and so trample a greater area of ground per unit distance travelled. We compared several real and hypothetical single- and multi-species ungulate communities using exponents of between 0.1 and 0.5 for the body mass to daily ranging distance relationship and found that the estimated area trampled was greater in communities dominated by larger animals. The impacts of large herbivores are not limited to trampling. Questions about the ecological implications of community body-size structure for such variables as foraging and food intake, dung quality and deposition rates, methane production, and daily travelling distances remain clear research priorities.

Animals↗

PubMed1994

Putative neuropeptide Y antagonist failed to decrease overeating in obese Zucker rats.

A central dysregulation of several neuropeptides could be at the origin of the marked hyperphagia of the obese Zucker rat, a well-known animal model used for the study of obesity. Neuropeptide Y (NPY), which stimulates food intake and increases early in life in obese rats, plays a major role in the development of this hyperphagia. The aim of our experiment was to test a proposed NPY antagonist namely PYX-2 in obese hyperphagic Zucker rats in order to know if it could be an interesting drug for limiting their food intakes. Four doses of PYX-2 (50-1000 pmol) were injected in a counterbalanced order in the lateral brain ventricles of 10 adult male Zucker rats. Food intake was recorded 0.5, 1, 2, 3, 6, and 23 h after PYX-2 injection and compared either to the rat's spontaneous food intake or to the food intake following injection of artificial CSF (vehicle) only. It was not modified by any dose of PYX-2 whatever the time considered (1 h after injection: 4.3 +/- 0.5 (1000 pmol) vs 4.6 +/- 0.8 (CSF) g; 23 h period: 27.0 +/- 1.9 (1000 pmol) vs 26.6 +/- 2.9 (CSF) g; N.S.). Thus, PYX-2, the putative NPY antagonist, totally failed to inhibit food intake in the obese rats. The absence of effect of PYX-2 on food intake can be explained by the structure of PYX-2, a modified 27-36 amino acid sequence that may not be recognized by the Y1-type NPY receptors which are involved in the regulation of feeding behavior.

Amino Acid Sequence↗

PubMed1980

Polymorphic trophonosis: the pseudo-omnivorous diet-related disease--a hypothesis.

Consideration of a wide range of seemingly disparate, non-infectious diseases reveals that most of them are only the varying forms or symptoms of a single, diet-related disease postulated to be Polymorphic Trophonosis. It is pointed out that they are all associated with pseudo-omnivorous dietary practices--negating the biological limitations of Homo omnivorus. In these practices, neither the out-of-all-proportion consumption of certain essential nutrients nor the liberal eating of new types of food seems to be suitable to the structure and mode of functioning of the digestive and/or metabolic systems.

Animals↗