Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Bus Contin Emer Plan ; 14(1): 46-54, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32847653

RESUMO

This paper explores the phases of emergency management following an incident through to continuity of operations. It summarises many of the obvious but often missed problems while responding to and recovering from an incident. The authors discuss what they feel is the key step in managing any incident or crisis - setting up the response quickly and correctly from the very beginning. They give insight about how to bring the right people into the room, how to communicate effectively throughout the incident and, most importantly, when to pull in the business continuity personnel so they can begin assessing the situation to ensure a smooth transition between phases and teams.


Assuntos
Planejamento em Desastres , Comércio
2.
J Physiol ; 597(9): 2337-2360, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30843201

RESUMO

KEY POINTS: Electrical pacemaking in gastrointestinal muscles is generated by specialized interstitial cells of Cajal that produce the patterns of contractions required for peristalsis and segmentation in the gut. The calcium-activated chloride conductance anoctamin-1 (Ano1) has been shown to be responsible for the generation of pacemaker activity in GI muscles, but this conclusion is established from studies of juvenile animals in which effects of reduced Ano1 on gastric emptying and motor patterns could not be evaluated. Knocking down Ano1 expression using Cre/LoxP technology caused dramatic changes in in gastric motor activity, with disrupted slow waves, abnormal phasic contractions and delayed gastric emptying; modest changes were noted in the small intestine. Comparison of the effects of Ano1 antagonists on muscles from juvenile and adult small intestinal muscles suggests that conductances in addition to Ano1 may develop with age and contribute to pacemaker activity. ABSTRACT: Interstitial cells of Cajal (ICC) generate slow waves and transduce neurotransmitter signals in the gastrointestinal (GI) tract, facilitating normal motility patterns. ICC express a Ca2+ -activated Cl- conductance (CaCC), and constitutive knockout of the channel protein anoctamin-1 leads to loss of slow waves in gastric and intestinal muscles. These knockout experiments were performed on juvenile mice. However, additional experiments demonstrated significant differences in the sensitivity of gastric and intestinal muscles to antagonists of anoctamin-1 channels. Furthermore, the significance of anoctamin-1 and the electrical and mechanical behaviours facilitated by this conductance have not been evaluated on the motor behaviours of adult animals. Cre/loxP technology was used to generate cell-specific knockdowns of anoctamin-1 in ICC (KitCreERT2/+ ;Ano1tm2jrr/+ ) in GI muscles. The recombination efficiency of KitCreERT was evaluated with an eGFP reporter, molecular techniques and immunohistochemistry. Electrical and contractile experiments were used to examine the consequences of anoctamin-1 knockdown on pacemaker activity, mechanical responses, gastric motility patterns, gastric emptying and GI transit. Reduced anoctamin-1 caused loss of gastric, but not intestinal slow waves. Irregular spike complexes developed in gastric muscles, leading to uncoordinated antral contractions, delayed gastric emptying and increased total GI transit time. Slow waves in intestinal muscles of juvenile mice were more sensitive to anoctamin-1 antagonists than slow waves in adult muscles. The low susceptibility to anoctamin-1 knockdown and weak efficacy of anoctamin-1 antagonists in inhibiting slow waves in adult small intestinal muscles suggest that a conductance in addition to anoctamin-1 may develop in small intestinal ICC with ageing and contribute to pacemaker activity.


Assuntos
Anoctamina-1/metabolismo , Motilidade Gastrointestinal , Intestino Delgado/fisiologia , Músculo Liso/metabolismo , Estômago/fisiologia , Animais , Anoctamina-1/genética , Bloqueadores dos Canais de Cálcio/farmacologia , Células Intersticiais de Cajal/metabolismo , Intestino Delgado/citologia , Intestino Delgado/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Nifedipino/farmacologia , Estômago/citologia , Estômago/crescimento & desenvolvimento
3.
J Toxicol Environ Health A ; 70(20): 1745-51, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17885931

RESUMO

The absorption, distribution, metabolism, and excretion of volatile organic compounds (VOCs) are critically determined by a few chemical-specific factors, notably their blood and tissue partition coefficients (PC) and metabolism. Age-specific values for PCs in rats have rarely been reported or utilized in pharmacokinetic modeling for predicting dosimetry in toxicity studies with rats progressing through their lifestages. A mixture of six VOCs (benzene, chloroform, methyl ethyl ketone, methylene chloride, trichloroethylene, and perchloroethylene) was used to determine blood:air and tissue:air PCs in rats at three different ages (postnatal d 10, 60 d, and 2 yr) and blood:air PCs in pediatric and adult human blood. No differences with age in human blood:air PCs for the six compounds were observed. Rat blood:air PCs increased with age varying with compound. Tissue:air PCs showed tissue-specific changes with age. Water-soluble methyl ethyl ketone showed no age-dependent differences. Partition coefficients, particularly the blood:air PC, are key determinants of the rodent and human blood concentrations; age-appropriate values improve the accuracy of pharmacokinetic model predictions of population variability and age-specific exposures.


Assuntos
Envelhecimento/metabolismo , Solventes/farmacocinética , Absorção , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Colesterol/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos/metabolismo , Ratos , Ratos Sprague-Dawley , Solventes/metabolismo , Distribuição Tecidual , Triglicerídeos/sangue
4.
Toxicol Sci ; 98(1): 43-56, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17426107

RESUMO

The capability of physiologically based pharmacokinetic models to incorporate age-appropriate physiological and chemical-specific parameters was utilized to predict changes in internal dosimetry for six volatile organic compounds (VOCs) across different ages of rats. Typical 6-h animal inhalation exposures to 50 and 500 ppm perchloroethylene, trichloroethylene, benzene, chloroform, methylene chloride, or methyl ethyl ketone (MEK) were simulated for postnatal day 10 (PND10), 2-month-old (adult), and 2-year-old (aged) rats. With the exception of MEK, predicted venous blood concentrations of VOCs in the aged rat were equal or up to 1.5-fold higher when compared to the adult rat at both exposure levels, whereas levels were predicted to be up to 3.8-fold higher in the case of PND10 at 50 ppm. Predicted blood levels of MEK were similar in the adult and aged rat, but were more than 5-fold and 30-fold greater for PND10 rats at 500 and 50 ppm, respectively, reflecting high water solubility along with lower metabolic capability and faster ventilation rate per unit body weight (BW) of PND10 animals. Steady-state blood levels of VOCs, simulated by modeling constant exposure, were predicted to be achieved in the order PND10 > adult > aged, largely due to increasing fat volume. The dose metric, total amount metabolized per unit liver volume was generally much lower in PND10 than in adult rats. The blood:air partition coefficient, fat volume, and fat blood flow were identified as critical determinants for the predicted differences in venous blood concentrations between the adult and aged. The lower metabolic capability, largely due to a smaller liver size, and faster ventilation rate per unit BW of PND10 animals contribute the most to the differences between PND10 and adult rats. This study highlights the pharmacokinetic differences and the relevant parameters that may contribute to differential susceptibility to the toxic effects of VOCs across life stages of the rat.


Assuntos
Envelhecimento/metabolismo , Compostos Orgânicos/farmacocinética , Compostos Orgânicos/toxicidade , Farmacocinética , Tecido Adiposo/metabolismo , Algoritmos , Animais , Barreira Alveolocapilar/fisiologia , Sistema Enzimático do Citocromo P-450/metabolismo , Previsões , Modelos Estatísticos , Ratos , Fluxo Sanguíneo Regional/fisiologia , Mecânica Respiratória , Distribuição Tecidual
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...