RESUMEN
Fruit flies are a familiar sight in many food service facilities. Although they have been long considered as "nuisance pests," some of their typical daily activities suggest they may pose a potential public health threat. The aim of this study was to provide evidence of the ability of small flies to transfer bacteria from a contaminated source, food, or waste to surfaces or ready-to-eat food. Laboratory experiments were conducted by using purpose-built fly enclosures to assess the bacterial transfer capability of fruit flies. Drosophila repleta were capable of transferring Escherichia coli O157:H7, Salmonella Saint Paul, and Listeria innocua from an inoculated food source to the surface of laboratory enclosures. In addition, using an inoculated doughnut and noncontaminated lettuce and doughnut surfaces, fly-mediated cross-contamination of ready-to-eat food was demonstrated. Fruit flies were shown to be capable of accumulating approximately 2.9 × 103 log CFU of E. coli per fly within 2 h of exposure to a contaminated food source. These levels of bacteria did not decrease over an observation period of 48 h. Scanning electron micrographs were taken of bacteria associated with fly food and contact body parts and hairs during a selection of these experiments. These data, coupled with the feeding and breeding behavior of fruit flies in unsanitary areas of the kitchen and their propensity to land and rest on food preparation surfaces and equipment, indicate a possible role for fruit flies in the spread of foodborne pathogens.
RESUMEN
The crucial first link between GnRH and its pleiotropic stimulation of the reproductive system is its receptor (GnRHRec). In mammals, 17beta-estradiol is a major regulator of GnRH action, and part of its regulation occurs at the level of the GnRHRec. In ovine pituitary cultures, estradiol simultaneously increases GnRHRec and GnRH-stimulated LH secretion (the LH response), but after 6-15 h the effect of estradiol becomes paradoxical, and the LH response rapidly decreases to control levels (by 24 h), whereas GnRHRec remains elevated. A preliminary study used photoaffinity labeling of the GnRHRec to show that estradiol can induce 38- and 43-kDa GnRHRec. The photoaffinity technique has been used here to 1) further investigate estradiol-mediated induction of GnRHRec, 2) define the nature of the different sized GnRHRecs, and 3) determine whether the larger size is related to degradation of the LH response. The effect of estradiol is compared with that of inhibin, which only induces the 38-kDa GnRHRec and always increases the LH response to GnRH treatment. Receptors for GnRH in ovine pituitary cultures were photoaffinity labeled with [125I](azidobenzoyl-D-Lys6-des-Gly10)-GnRH-N-ethylamide and analyzed by SDS-PAGE. Treatment with estradiol or inhibin for 6-24 h induced a 38-kDa GnRHRec only. Further treatment with estradiol (>24 h), but not inhibin, shifted the apparent Mr of the GnRHRec to 43 kDa. Phosphatase treatment did not reverse this apparent Mr change. Analysis of receptor glycosylation using N-glycosidase F or tunicamycin showed that the 43-kDa GnRHRec was a hyperglycosylated form of the 38-kDa GnRHRec. The 38-kDa GnRHRec, in turn, was a glycosylated form of the 29-kDa GnRHRec. The studies presented here define several glycosylated intermediates of the ovine GnRHRec that are induced by estradiol and/or inhibin. The function of estrogen-mediated hyperglycosylation is unclear, but kinetic studies dissociate it from degeneration of the LH response to GnRH.
Asunto(s)
Estradiol/farmacología , Receptores LHRH/biosíntesis , Animales , Antibacterianos/farmacología , Azidas , Western Blotting , Bovinos , Células Cultivadas , Electroforesis en Gel de Poliacrilamida , Glicosilación , Humanos , Hidrólisis , Inhibinas/farmacología , Radioisótopos de Yodo , Hormona Luteinizante/metabolismo , Monoéster Fosfórico Hidrolasas/química , Etiquetas de Fotoafinidad , Receptores LHRH/metabolismo , Proteínas Recombinantes/farmacología , Ovinos , Tunicamicina/farmacologíaRESUMEN
"Synergism" accurately describes the gains that can be made when total quality management (TQM) and shared governance are employed for reciprocal development. This article explores the relationship between TQM and shared governance from a systems perspective. Systems thinking is the fundamental framework that must be learned by nursing managers. An example of this synergistic process is described from the National Institutes of Health nursing department's experience in implementing TQM and shared governance. The idea that structure is fundamental to problems and solutions when implementing change and focusing upon interdependency issues are the systemic competencies nursing managers need to develop in order to become strong nursing leaders.