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J S Koenig

Publications and source records attributed to J S Koenig.

9 recordsLinked to original sources
PubMed2002

Operationalization of food consumption surveys in Europe: recommendations from the European Food Consumption Survey Methods (EFCOSUM) Project.

BACKGROUND: The EFCOSUM (European Food Consumption Survey Methods) Project aims at harmonizing food consumption surveys in European countries within the perspective of an overall Public Health Monitoring Programme. Harmonization implies the need for a common framework of procedures and tools, that are applicable and feasible in all potentially interested countries. A major element in such a framework is the protocol for the operationalization of a food consumption survey, referring to all practical, logistical and material conditions that need to be fulfilled in order to guarantee a successful implementation of such a survey. OBJECTIVE: The objective of this paper was to review a number of aspects of operationalization of food consumption surveys in detail. On the basis of the currently available knowledge and experience in Europe, consensus recommendations have been elaborated for an operationalization protocol that would be feasible for all European countries. METHODS: The EFCOSUM recommendations with respect to operationalization of food consumption surveys in Europe are mainly based on three sources of information, which have been discussed at several ad hoc expert meetings: experience from previous collaborative epidemiological studies, literature searches and results of two questionnaires, distributed among representatives from 23 European countries-all experts affiliated with experienced organizations in the fields of nutrition research and related fields. RESULTS: Consensus recommendations have been set up for the following topics: sampling, recruitment, fieldwork, biomarkers, interviewer qualifications and training and quality control. These recommendations have to be considered the best achievable common denominator within Europe at this time. In a number of cases, recommendations are presented in a hierarchical way, with a gradation from first choice options towards acceptable alternatives. CONCLUSIONS: It can be concluded that a high degree of standardization of fieldwork can be achieved within Europe. A number of specific problems and constraints will have to be solved in connection with the conduction of a real survey. These problems include, amongst others, country-specific decisions on, for example, target population, detailed sampling and recruiting procedures, interview setting and support. However, on the whole, these problems can be overcome and the main recommendations presented in this paper are considered feasible for every country in Europe. Application of the EFCOSUM operationalization protocol in European countries will contribute significantly to the quality and comparability of food consumption data across Europe. It is anticipated that the policy supporting and orienting potential of this type of databases-both at the national and at the EU supranational level-will be increased accordingly.

Data Collection↗
PubMed1997

Antioxidant status in patients on chronic hemodialysis therapy: impact of parenteral selenium supplementation.

Reactive oxygen species may be involved in a broad pattern of tissue injury in patients on regular hemodialysis therapy and, in fact, increasing evidence suggests that the antioxidative system is compromized in these patients. One factor contributing to this reduction of antioxidative capacity is selenium deficiency. The present investigation was undertaken to further define the extent and type of impairment of the oxygen radical scavenger system in chronic hemodialysis patients and to evaluate the impact of selenium supplementation. Twelve non-wasted patients (6 male, 6 female, mean age of 58 years) on chronic hemodialysis for a minimum of 5 months (mean 46 months) were supplemented intravenously with 400 mg selenium (as sodium selenite) thrice weekly after each hemodialysis session over 8 weeks. Blood samples were taken before the start, at intervals of 2 weeks during, and 4 weeks after termination of supplementation. Concentrations were evaluated of selenium and alpha-tocopherol in plasma and erythrocytes, of retinol and ascorbic acid in plasma, of glutathione and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and, catalase (CAT) in erythrocytes. Lipid peroxidation endproducts were measured as malondialdehyde (MDA) in plasma. In patients on hemodialysis multiple alterations of the antioxidative system were present and the concentrations of selenium in plasma, of glutathione and the activity of GSH-Px in erythrocytes were profoundly decreased (p < 0.001). Selenium supplementation improved the selenium status of the patients, as indicated by an increase in selenium concentrations in plasma and erythrocytes and erythrocyte GSH-Px activity. Improvement in antioxidative capacity was further documented by an increase in alpha-tocopherol in erythrocytes. Plasma MDA showed a transient decrease after 6 weeks and increased activities of SOD and CAT were dampened. No effect was seen on plasma concentrations of ascorbic acid, a-tocopherol and retinol. We conclude that patients on chronic hemodialysis therapy manifest a profound depression in antioxidative potential and a selenium deficiency. Selenium supplementation improves the oxygen radical scavenger system and increases selenium concentrations in plasma and erythrocytes and the activity of selenium dependent glutathione peroxidase. Thus, selenium should also be considered for micronutrient supplementation in patients on chronic hemodialysis therapy.

Adult↗
PubMed1990

Coordination of breathing, sucking, and swallowing during bottle feedings in human infants.

Incoordination of sucking, swallowing, and breathing might lead to the decreased ventilation that accompanies bottle feeding in infants, but the precise temporal relationship between these events has not been established. Therefore, we studied the coordination of sucks, swallows, and breaths in healthy infants (8 full-term and 5 preterm). Respiratory movements and airflow were recorded as were sucks and swallows (intraoral and intrapharyngeal pressure). Sucks did not interrupt breathing or decrease minute ventilation during nonnutritive sucking. Minute ventilation during bottle feedings was inversely related to swallow frequency, with elimination of ventilation as the swallowing frequency approached 1.4/s. Swallows were associated with a 600-ms period of decreased respiratory initiation and with a period of airway closure lasting 530 +/- 9.8 (SE) ms. Occasional periods of prolonged airway closure were observed in all infants during feedings. Respiratory efforts during airway closure (obstructed breaths) were common. The present findings indicate that the decreased ventilation observed during bottle feedings is primarily a consequence of airway closure associated with the act of swallowing, whereas the decreased ventilatory efforts result from respiratory inhibition during swallows.

Bottle Feeding↗
PubMed1989

Characteristics of upper airway chemoreflex prolonged apnea in human infants.

Water instilled into the pharynx of sleeping human infants elicits a range of chemoreflex responses that, occasionally, includes prolonged apnea (defined as absence of ventilation for at least 20 s, or for a shorter period if accompanied by bradycardia of less than or equal to 100 b.p.m. or cyanosis). To learn more about airway receptors mediating this prolonged apneic response and factors determining its occurrence, we examined the importance of stimulus location and associations between prolonged apnea, bradycardia, and upper airway responses. A total of 29 episodes of prolonged apnea were recorded after water stimulation in 12 infants. Bradycardia (HR less than 100) followed stimulus delivery but was always preceded by apnea and did not appear as an independent chemoreflex response. Behavioral arousal and prolonged apnea were not mutually exclusive responses and recovery from prolonged apnea was not always closely linked with arousal. Occurrence of prolonged apnea was greater after pharyngeal than nasal stimulation, and was frequently associated with coughing, but not with sneezing, suggesting that prolonged apnea is elicited from a sensory site close to, or the same as, one mediating cough. We conclude, using this water stimulus method, that the predominant receptors for chemoreflex-prolonged apnea are located in the pharynx or larynx rather than in the nose.

Apnea↗
PubMed1988

Upper airway chemoreflex responses to saline and water in preterm infants.

Laryngeal chemoreflex (LCR) responses elicited by fluid irrigation of the larynx have been described repeatedly in animals, whereas evidence for a similar reflex in human infants is extremely limited. Using nasopharyngeal catheters to instill small volumes of warm saline or water into the pharynx, we examined the incidence and characteristics of such a reflex in nine premature infants. Saline and water elicited the same pattern of responses, which frequently included swallows, central apnea, and airway obstruction and less commonly featured coughs, prolonged apnea, and arousal. With the exception of arousal, the incidence of these responses was significantly greater after delivery of water stimuli than after saline bolus administration. We therefore deduce chemoreceptor involvement in generation of these reflex responses and propose a laryngeal site for this sensory system, as in animals. Since greater potency of water compared with saline was demonstrable in all the infants studied, we further conclude that most preterm infants possess an upper airway chemoreflex.

Apnea↗
PubMed1988

Effects of mass loading on the upper airway.

To learn how increased cervical adipose tissue might affect upper airway function, we studied effects of mass loading on upper airway dimensions, stability, and resistance. Eight rabbits were studied (anesthetized and postmortem) using lard-filled bags to simulate cervical fat accumulation. Additionally, a handheld device was used to apply measured loads at localized sites along the airway. Upper airway resistance and closing pressure (a reflection of airway stability) were determined before and after loading. Endoscopy revealed concentric narrowing of the pharynx during loading in anesthetized and postmortem preparations. Upper airway resistance was increased by mass loads, with larger loads having greater effects. Loading caused decreased airway stability as reflected by closing pressures. The area over the thyrohyoid membrane was more vulnerable to mass loading than adjacent areas. Because mass loading of the upper airway causes changes in its configuration and function similar to those seen in obstructive sleep apnea syndrome (OSA), we speculate that such loading may contribute to the pathogenesis of OSA associated with obesity.

Adipose Tissue↗