The placental transport of [³H]vitamin K₁ in rats

In this paper we describe the placental transport of [3H]vitamin K1 in pregnant rats during the first 24 h after the oral administration of the vitamin. Vitamin K1 in the fetal livers ranged from 0.13% (3 h) to 2% (24 h) of the values found in the corresponding maternal livers. In spite of the low placental transfer of vitamin K, we found no accumulation of coagulation factor precursors in the fetal rat liver microsomes as could be expected in vitamin K deficiency. Moreover, we could not demonstrate any difference between adult and fetal rat liver microsomes with regard to the sensitivity for warfarin. From these results we conclude that a substantial placental barrier exists for the transport of pharmacological amounts of vitamin K1 but that under physiological conditions sufficient vitamin K1 appears to be present in the fetal liver to ensure a full carboxylation reaction. The vitamin K-dependent carboxylase activity rate of adult and fetal rat liver microsomes was comparable, indicating that the newborn rat has an adequate carboxylating system

Contestable adulthood: variability and disparity in markers for negotiating the transition to adulthood

Recent research has identified a discreet set of subjective markers that are seen as characterizing the transition to adulthood. The current study challenges this coherence by examining the disparity and variability in young people’s selection of such criteria. Four sentence-completion cues corresponding to four differentcontexts in which adult status might be contested were given to 156 British 16- to 17-year-olds. Their qualitative responses were analyzed to explore patterns whilst capturing some of their richness and diversity. An astonishing amount of variability emerged, both within and between cued contexts.The implications of this variability for how the transition to adulthood is experienced are explored. The argument is made that markers of the transition to adulthood are not merely reflective of the bio–psycho–social development of young people. Rather, adulthood here is seen as an essentially contested concept,located within the discursive interactional environment in which young people participate

Life path analysis: scaling indicates priming effects of social and habitat factors on dispersal distances

1. Movements of many animals along a life-path can be separated into repetitive ones within home ranges and transitions between home ranges. We sought relationships of social and environmental factors with initiation and distance of transition movements in 114 buzzards Buteo buteo that were marked as nestlings with long-life radio tags. 2. Ex-natal dispersal movements of 51 buzzards in autumn were longer than for 30 later in their first year and than 35 extra-natal movements between home ranges after leaving nest areas. In the second and third springs, distances moved from winter focal points by birds that paired were the same or less than for unpaired birds. No post-nuptial movement exceeded 2 km. 3. Initiation of early ex-natal dispersal was enhanced by presence of many sibs, but also by lack of worm-rich loam soils. Distances travelled were greatest for birds from small broods and with relatively little short grass-feeding habitat near the nest. Later movements were generally enhanced by the absence of loam soils and short grassland, especially with abundance of other buzzards and probable poor feeding habitats (heathland, long grass). 4. Buzzards tended to persist in their first autumn where arable land was abundant, but subsequently showed a strong tendency to move from this habitat. 5. Factors that acted most strongly in ½-km buffers round nests, or round subsequent focal points, usually promoted movement compared with factors acting at a larger scale. Strong relationships between movement distances and environmental characteristics in ½-km buffers, especially during early ex-natal dispersal, suggested that buzzards became primed by these factors to travel far. 6. Movements were also farthest for buzzards that had already moved far from their natal nests, perhaps reflecting genetic predisposition, long-term priming or poor habitat beyond the study area

'Education, education, education' : legal, moral and clinical

This article brings together Professor Donald Nicolson's intellectual interest in professional legal ethics and his long-standing involvement with law clinics both as an advisor at the University of Cape Town and Director of the University of Bristol Law Clinic and the University of Strathclyde Law Clinic. In this article he looks at how legal education may help start this process of character development, arguing that the best means is through student involvement in voluntary law clinics. And here he builds upon his recent article which argues for voluntary, community service oriented law clinics over those which emphasise the education of students

Fat and carbohydrate metabolism during and following hemorrhagic shock in puppies: A comparison of different resuscitation protocols

Shock states continue to carry a high mortality rate in the pediatric age group. Using a puppy model, we measured the initial metabolic response to hemorrhagic shock and to 3 resuscitation regimens: whole blood 1∶1 (replacement∶shed), lactated Ringer's 3∶1, and 5% albumin in lactated Ringer's 1∶1. Despite the immature nature of the puppy's enzyme, cardiovascular, and nervous systems, responses very similar to those in adult animals were seen. Serum glucose and free fatty acids rose during shock and declined with resuscitation as cardiac output returned toward normal. Serum lactate levels rose similarly but continued to rise for a short period after resuscitation and were associated with a further fall in pH consistent with “hidden acidosis.” Only small changes were noted in triglyceride and cholesterol levels. The metabolic responses noted following each of the 3 resuscitation protocols were similar. This study suggests that the immature animal responds to hemorrhagic shock in ways similar to the adult. The better initial hemodynamic response to resuscitation with high-volume lactated Ringer's or lactated Ringer's with 5% albumin was offset by the better buffering capacity of blood resuscitation. All 3 regimens were equally efficacious in providing initial metabolic recovery in this experimental hemorrhagic shock model. Les états de choc s'accompagnent d'une mortalité élevée chez les enfants. En ayant recours à l'expérimentation chez le chiot, les auteurs ont mesuré les modifications métaboliques initiales en réponse au choc hémoragique et à sa correction par 3 agents différents: sang complet (1∶1), solution de Ringer (3∶1) et solution de Ringer enrichie de 5% d'albumine. Malgré la nature immature des enzymes du chiot, du système cardio-vasculaire et du système nerveux, les réponses furent identiques à celles observées chez le chien adulte. Le glucose et les acides gras libres s'élevèrent au cours du choc et s'abaissèrent lors de la réanimation dès que le débit cardiaque revint à la normale. Les niveaux du lactate sanguin s'élevèrent de la même manière mais l'élévation continua pendant une courte période après la réanimation, cependant que le pH s'abaissait, démasquant une “acidose cachée”. Les taux des triglycérides et du cholestérol furent seulement discrètement altérés. Les réponses métaboliques étudiées en fonction des 3 méthodes de réanimation furent identiques. Cette étude suggère que le chiot répond de la même façon que le chien adulte au choc hémorragique et que les 3 méthodes de réanimation employant chacune des agents différents ont une efficacité identique. Los estados shock mantienen una elevada mortalidad en los grupos de edad pediátrica. Utilizando un modelo de shock en cachorros, se determinó la respuesta metabólica inicial al shock hemorrágico y a tres diferentes regimenes de resucitación: sangre total 1∶1 (reemplazo: pérdida), lactato de Ringer 3∶1, y albúmina al 5% en lactato de Ringer 1∶1. A pesar de la naturaleza inmadura de los sistemas enzimático, cardiovascular y nervioso del cachorro, las respuestas fueron muy similares a las observadas en animales adultos. La glucosa sérica y los ácidos grasos libres ascendieron durante el shock y declinarion en la medida que el débito cardiaco retornaba a lo normal. Los niveles de lactato sérico ascendieron en forma similar, pero continuaron su ascenso por un corto periodo de tiempo después de la resucitación, encontrándose asociados con una caida adicional del pH consistente con “acidosis oculta”. Sólo se presentaron cambios leves en los niveles de triglicéridos y colesterol. Las respuestas metabólicas observadas en cada uno de los tres protocolos de resucitación fueron similares. Este estudio sugiere que el animal inmaduro responde al shock hemorrágico de manera similar al adulto. La mejor respuesta hemodinámica inicial a la resucitación con altos volúmenes de lactato de Ringer o con lactato de Ringer con albúmina al 5%, fue compensada con una mejor capacidad de amortiguación observada en la resucitación con sangre. Los tres regimenes fueron igualmente eficaces en lograr la recuperación metabólica inicial en este modelo experimental de shock hemorrágico.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41311/1/268_2005_Article_BF01655348.pd