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PubMedDate not supplied

[Functional status of brain structures during exposure to anticipatory and trigger signals for feeding behavior].

The difference index of functional states of brain structures (the hippocampus, amygdala, frontal cortex) was estimated in dogs under the action of anticipating and triggering signals of a complex conditioned stimulus consisting of two similar tones, divided by a pause. It was found that during both signals the functional states of the brain structures were equivalent, though food-procuring behaviour of the animals under the action of the anticipating stimulus was inhibited. This fact corroborates the assumption that reactions of inhibitory type are determined by a high level of the brain structures functional state.

Amygdala↗
PubMed1994

Food aversion induced by area postrema ablation.

Rats with lesions of the area postrema (APX rats) avoid foods ingested on a regular basis during the period of severe hypophagia immediately following surgery (Tomoyasu & Kenney, 1989). The present work determined whether APX rats would also avoid foods to which they are exposed only after they have recovered from the lesion-induced hypophagia. APX and SHAM-lesion rats were fed a novel food for 8 days beginning at least 1 month after surgery when food intakes (adjusted for body weight) and weight gains of the APX rats had returned to control levels. During 24 h, two-food choice tests, APX rats avoided the food ingested a month after the ablation while avidly ingesting an alternative food, but SHAM rats showed no preference between the foods. There was no indication that this aversion developed by APX rats to foods ingested after recovery from hypophagia is weaker than that developed to foods ingested immediately after the lesion. We conclude that area postrema ablation results in the development of an unconditioned stimulus capable of supporting food-aversion conditioning which remains effective more than 1 month after the ablation. Hence, the relationship between APX-induced food aversion and hypophagia must be indirect and complex. Also, conditioning of food aversions induced by area postrema ablation alone may confound studies of the role of this structure in mediating the development of food aversions after other physiological and/or pharmacological manipulations.

Animals↗
PubMed2005

Characterization of the interaction between two food aroma components, alpha-pinene and ethyl butyrate, and ethylene-vinyl alcohol copolymer (EVOH) packaging films as a function of environmental humidity.

The ethylene-vinyl alcohol copolymers (EVOHs) are well-known high oxygen barrier materials that are being used successfully in the design of packaging structures for oxygen-sensitive food or pharmaceutical products. Recently, there has been increasing interest in using EVOH materials to provide a high barrier to organic compounds as a means to reduce food aroma scalping. However, the barrier function of this family of materials diminishes significantly in humid environments, and it is supposed that so does the organic vapor barrier. In this work, a new sorption-based method to characterize the interaction between food aroma and polymer films for packaging as a function of relative humidity is presented and is used to determine the barrier to ethyl butyrate and alpha-pinene of EVOH at 23 degrees C. The results show that although EVOH is an excellent barrier to food aroma when dry, a property that even improves at low relative humidity (RH), the solubility and diffusivity of the compounds tested increase dramatically with humidity at medium to high water activities. However, even in the worst case (100% RH), EVOH outperforms low-density polyethylene (LDPE) as a barrier to organic vapors at least 500,000-fold.

Bicyclic Monoterpenes↗
PubMed2004

Neuron production, neuron number, and structure size are seasonally stable in the hippocampus of the food-storing black-capped chickadee (Poecile atricapillus).

Neuronal recruitment in the black-capped chickadee (Poecile atricapillus) hippocampus occurs at a higher rate in the fall than at other times of the year. As a means of determining whether this increase in recruitment results from greater neuron production, chickadees were caught in the wild between October and March and injected with the cell-birth marker 5-bromo-2'-deoxyuridine. Two weeks later, birds were killed by overdose, and hippocampal neuron production, apoptosis, neuron number, and hippocampal volume were determined. Chickadees collected in October, November, January, February, and March did not differ in neuron production, apoptosis, hippocampal volume, or neuron number. These findings indicate that increases in neuronal recruitment in the chickadee hippocampus in the fall do not result from increased neuron production, but instead, enhanced survival of new neurons.

Animals↗
PubMed2002

Knowledge and practices of a control authority: impact on the environment and food safety.

This study investigates the practices and knowledge of a Control Authority dealing with the environment and the safety and control of hawker foods. Experience and background education are used as likely determinants of food safety practices and knowledge of the control authority. A total of 60 questionnaires were distributed to the Health Inspectors (HIs) in the Hawkers' and Health Departments, City Hall, Kuala Lumpur. The return rate was 93%. The structured questionnaire contained 14 main food safety practices and knowledge constructs. Significance was found pertaining to knowledge of HIs with different experience backgrounds but experience was not demonstrated to impact on practices of HIs. However, education was noted to have significantly but inconsistently influenced certain Practices and Knowledge scores of HIs. A Pearson bivariate coefficient characterised an association between food safety practices and knowledge of the control authority. The findings: (1) highlight the actual shortcomings in the staff resources relating to environmental health, food safety, foodborne illnesses and their control, and (2) provide information on the control aspect within the hawker micro-industry with the view of protecting the public from health hazards arising from the hawkers' practices and consumption of hawker foods.

Food Contamination↗
PubMed2025

Genomic structure of class 1 and 2 integrons in non-typhoidal Salmonella isolated from food animals and related meat products in the USA.

OBJECTIVES: Integrons facilitate the capture and expression of exogenous genes, including antimicrobial resistance (AMR) genes. This study aimed to detect the presence of integrons, examine their genomic structure and location, and analyse integron-associated AMR, virulence and stress response genes in Salmonella using WGS. METHODS: WGS data from 193 Salmonella strains, representing 38 serotypes isolated from food animals and related meat products (2001-2019), were analysed using bioinformatic tools to assess integron presence and characterize their genomic architectures. RESULTS: Of 193 isolates, 116 (60.1%) harboured class 1 and/or class 2 integrons. Class 1 integrons alone were detected in 105 isolates, with some containing multiple copies. One S. Infantis isolate harboured only class 2 integrons, whereas 10 others contained both classes. No class 3-5 integrons were found. Twenty-seven class 1 integrons were chromosomal; the rest were plasmid-associated, linked to various plasmid incompatibility (Inc) types. Sixty-nine distinct AMR genes conferring resistance to 11 antimicrobial classes were found in integron cassettes or integron-associated plasmids. Genes linked to resistance to quaternary ammonium compounds and heavy metals, as well as ISs and transposons, were also identified. Significant virulence and stress response genes and proteins such as groES-groEL, LysR and EAL (glutamate, alanine and leucine) were common in integron cassettes. CONCLUSIONS: Class 1 integrons are prevalent in MDR Salmonella isolates from food animals and related meat products and are linked to diverse plasmid types. Their association with AMR, virulence and stress response genes underscores their role in AMR dissemination, and bacterial adaptation and pathogenicity.

Integrons↗
PubMed1995

Assessment of exposure to chemical contaminants in water and food.

UNLABELLED: The main questions on the validity of the studies and routine monitoring (e.g., in the scope of the WHO/UNEP GEMS programme) assessing exposure to chemicals through water and food (i.e., through digestion) relate to the following. (a) SAMPLING: variations due to sampling strategy and approach usually exceed analytical errors. (b) MEASUREMENT: quality assessment and quality control (QA/QC) procedures are essential. However, potential limitations of measurement errors resulting from implementation of these procedures should be kept in perspective with other errors and confounding factors. (c) METHODOLOGY: which depends on the variability of the intake patterns in the population, as well on the adequacy of the information on the consumption of food of a specified type as an indicator of the intake of a specific chemical. These factors should be considered in particular in studies using 'food basket' methods. Whenever possible, structure of the population in respect to the factors determining typical diet should be registered. (d) Form of reporting: limiting possibilities for re-analysis of the exposure estimates. In conclusion, the routinely collected data on exposure through food and water should be used with care in epidemiological studies. Assessment of the exposure conducted specially for the epidemiological study should consider possible changes of the diet with time. The data on confounders are crucial for exposure estimates.

Cadmium↗
PubMed1983

United States Food and Drug Administration approach to risk evaluation and risk management for foods.

The Food and Drug Administration (FDA) is developing a comprehensive program on risk evaluation and risk management related to foods and food ingredients. Various groups view the FDA differently in terms of potential food hazards, but the regulatory agency is required to follow the laws that reflect a set of social judgments about permissible risks and benefits. The traditional agency approaches to risk management are reviewed and recent plans to consider structural changes in the basic food statute that could lead to greater administrative flexibility are presented. The proposed tentative suggestions discussed embody basic principles that the public health and trust remain the focus of food safety laws. Public confidence in the present system must be retained, it must be a credible system, embody valid scientific data, and the regulatory actions must be taken by FDA scientists who are recognized for their scientific competence. All the proposed actions need to be taken without placing unnecessary economic burdens on industry. The scope of this program is reviewed.

Food Additives↗
PubMed1989

Food and Drug Administration: approach to evaluating neurotoxicity.

One of the primary features of the mission of the Food and Drug Administration is to assure with reasonable certainty that no harm will result from the intended use of chemicals added to food. In carrying out this mission the FDA uses a structured process to assess the safety of each food chemical. The detailed mechanics of this process are described in an FDA document entitled "Toxicological Principles for the Safety Assessment of Direct Food Additives and Color Additives Use in Food" (Food and Drug Administration, 1982). Central to its evaluation the FDA requires a collective set of information, including estimates of the anticipated human exposure to the food chemical and a broad-based toxicological profile. Certainly, any adverse effect observed in the nervous system is recognized as an important element in the determination of chemical safety and follow-up information which would enable an assessment of such an effect to be included in the toxicological profile. The agency's current approach to evaluating neurotoxicity should be viewed within the context of its overall strategy for the safety assessment of food chemicals. Four basic premises underlie the FDA's approach to safety assessment.

Animals↗
PubMedDate not supplied

Biocultural construction of obesogenic ecologies of childhood: parent-feeding versus child-eating strategies.

Human biologists recognize the centrality of parental feeding beliefs and related practices in structuring children's under-nutrition risk in food-insecure settings. By contrast, how they might similarly structure children's nutrition-related health risks in calorically rich ecologies has barely been considered. Using the case of 3- to 6-year-old children in a rural Southeastern U.S. community with very high obesity rates, we use cognitive methods such as consensus analysis to determine how parental cultural models of child eating and feeding are linked to high calorie, obesogenic child diets. We find that parental models are very consistent with biomedical understandings (reduce fat, reduce sugar, portion control, etc.). Regardless, children's diets are extremely high in calories overall as well as in high sugar and fat food items. We suggest three likely and mutually reinforcing contributing factors to persistent and increasing early childhood overweight and obesity: parents' ambivalence about modeling healthy eating, children's active resistance, and the balance of parents' social against nutritive goals at meal times. The active role of children as social architects of their own biology has been little explored in human biological studies, and should provide novel and important understandings of the biocultural construction of childhood over-nutrition.

Adult↗
PubMed1995

Who is nutritionally vulnerable in Bosnia-Hercegovina?

OBJECTIVE: To monitor nutritional status and food security in order to identify nutritionally vulnerable groups. DESIGN: Members of five different household groups (urban and rural residents, displaced people in collective centres and private accommodation, elderly people living without younger family) and all residents of two old people's homes were prospectively followed. Households were selected from 20 local communities and nine collective centres. SETTING: Monitoring carried out in three besieged areas of Bosnia-Hercegovina (Sarajevo, Tuzla, and Zenica). SUBJECTS: 1739 individuals sampled. INTERVENTIONS: Data collected every month from December 1993 to May 1994. Information on household food security was collected through structured questionnaires. All subjects were weighed and their heights measured. Weight for age Z scores were calculated for children; body mass index was calculated for adults and elderly people. RESULTS: From December 1993 to February 1994, before a temporary cease fire, access to food was reduced. In February 1994 no significant signs of undernutrition were detected among children or adults, but elderly people had higher than expected levels of undernutrition (15.5% with body mass index < 18.5), a higher rate of weight loss than adults (1.2 kg over two months), and a higher prevalence of self reported illness. CONCLUSIONS: Elderly people in Bosnia-Hercegovina are at greater risk of undernutrition than other age groups. Undernutrition may be precipitated in elderly people by sickness, cold, stress, and problems related to food preparation. The health and welfare of elderly people during the emergency in Bosnia-Hercegovina require special attention, and integrated age care programmes are needed.

Adolescent↗
PubMed1996

The economy of winter: phenotypic plasticity in behavior and brain structure.

Mobile animals must learn the spatial distributions of resources. The cost of foraging increases dramatically for temperate-zone animals during the winter. Two strategies may be used to balance the energetic budget: reducing costs of foraging and reducing need to forage. Both strategies are correlated with changes in brain structure, specifically in the hippocampus, a fore-brain structure used by birds and mammals to map spatial distributions of resources. Small mammals that reduce their need to forage, through hibernation or reduction in body size, show a specific reduction in the structure and size of the hippocampus. The costs of foraging can be also decreased by migration to better foraging conditions or by food-storing, both of which decrease the temporal heterogeneity of food resources. Both of these latter strategies are associated with increased hippocampal structure; for food-storing birds, this increase is a seasonal phenomenon. Thus not only behavior, but also learning ability and even brain structures in adult animals, may be phenotypically plastic in response to the changing demands of the environment.

Adaptation, Physiological↗
PubMed2000

Redox control and the evolution of multicellularity.

Redox chemistry, involving the transfer of electrons and hydrogen atoms, is central to energy conversion in respiration; in addition, control of gene expression by redox state commonly occurs in bacteria, allowing a rapid response to environmental changes, such as altered food supply. Colonial metazoans often encrust surfaces over which the food supply varies in time or space; hence, in these organisms redox control of the development of feeding structures and gastrovascular connections could be similarly adaptive, allowing colonies to adjust the timing of development and spacing of structures in response to a variable food supply and other environmental factors. Experimental perturbations of redox state in colonial hydroids support this notion of adaptive redox control, and redox signaling in metazoans may have evolved in this ecological context. At the same time, redox signaling has important consequences for the evolutionary transition from unicellular to multicellular organisms. Unlike protein or peptide signaling, redox signaling acting in concert with programmed cell death may automatically inflict a cost on those cells that "defect," that is, selfishly favor their own replication rate over that of the multicellular group. In this way, redox signaling may have allowed multicellular individuality to evolve and more easily be maintained.

Animals↗
PubMed2005

Analytical methodology for assessment of food allergens: opportunities and challenges.

This review summarizes the available in vitro, in vivo, and informatic methods designed to evaluate different aspects of the capacity of proteins to act as true food allergens. By now, there is no single method to fully assess the potential allergenicity of proteins. The characterization of many food allergens will help to uncover the sequential and structural motifs that determine the behaviour of proteins as food allergens.

Allergens↗
PubMed1999

Redox control in development and evolution: evidence from colonial hydroids

Redox chemistry, involving the transfer of electrons and hydrogen atoms, is central to energy conversion in respiration, and the control of gene expression by redox state commonly occurs in bacteria, allowing rapid responses to environmental changes, for instance, in the food supply. Colonial metazoans often encrust surfaces over which the food supply varies in time or space; hence, in these organisms, redox control of the development of feeding structures and gastrovascular connections could be similarly adaptive, allowing colonies to adjust the timing and spacing of structures in response to a variable food supply. To investigate the possibility of redox control of colony development, the redox states of hydractiniid hydroid colonies were manipulated experimentally. As in many colonial animals, hydractiniid hydroids display a range of morphological variation from sheet-like forms (i.e. closely spaced polyps with high rates of stolon branching) to runner-like forms (i. e. widely spaced polyps with low rates of stolon branching). In the runner-like Podocoryna carnea, azide, a blocker of the electron transport chain, and dinitrophenol, an uncoupler of oxidative phosphorylation, diminished the largely polyp-driven gastrovascular flow to a similar extent. Measures of the redox state of the polyp epitheliomuscular cells using the fluorescence of NAD(P)H suggest that azide shifts the redox state in the direction of reduction, while dinitrophenol shifts the redox state in the direction of oxidation. Colony development corresponds to redox state in that azide-treated colonies were more runner-like, while dinitrophenol-treated colonies were more sheet-like. Nevertheless, the functional role of polyps in feeding and generating gastrovascular flow probably contributed to a trade-off between polyp number and size such that azide-treated colonies had few large polyps, while dinitrophenol-treated colonies had many small polyps. Regardless of the treatment, P. carnea colonies developed to maturity and produced swimming medusae in the normal fashion. In the sheet-like Hydractinia symbiolongicarpus, treatment with azide resulted in complete suppression of the development of both the stolonal mat and the blastostyles, the reproductive polyps. Azide-treated H. symbiolongicarpus colonies therefore developed in a juvenilized, runner-like manner and much resembled colonies of P. carnea. Following cessation of azide treatment in H. symbiolongicarpus, normal colony development ensued, and both a stolonal mat and blastostyles formed. In both hydroid species, relative oxidization favors sheet-like growth, while relative reduction favors runner-like growth. Since feeding triggers strong contractions of polyp epitheliomuscular cells and results in relative oxidation, this experimental evidence supports the hypothesis of adaptive redox control of colony development and evolution.

Journal Article↗