St Thomas' Hospital

About: St Thomas' Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Pregnancy. The organization has 12105 authors who have published 15596 publications receiving 624309 citations. The organization is also known as: St Thomas's Hospital & St. Thomas's.

Variation in bronchial responsiveness in the European Community Respiratory Health Survey (ECRHS)

Abstract: Attempts to compare bronchial responsiveness between populations have been hampered by between-study differences in the pharmacological agent of provocation, the method of administration and the summary statistic employed. The European Community Respiratory Health Survey used methacholine challenge delivered by Mefar dosimeter according to a standardized protocol used in 35 centres in 16 countries. Data were obtained from 13,161 men and women, aged 20-44 yrs at the start of the study. The dose of methacholine producing a 20% fall in forced expiratory volume in one second (FEV1) (PD20) and the regression coefficient of percentage decline in FEV1 with log dose, were calculated ("slope", after transformation), with and without calibration of nebulizers by weight and adjustment for nonresponse bias. Standardization for baseline lung function and variation in smoking prevalence was applied to slope. Results were robust to whichever summary measure was used, and to the various adjustments. Responsiveness was low in Iceland and Switzerland, and in most centres in Sweden, Italy and Spain, and high in New Zealand, Australia, the USA, Britain, France, Denmark and Germany. Bronchial responsiveness varies considerably in Europe, and high levels are not confined to the English-speaking world.

Uptake of plasma fibrinogen into the alpha granules of human megakaryocytes and platelets

Abstract: The origin of platelet alpha-granule fibrinogen (Fg), whether from endogeneous synthesis or exogeneous derivation, remains unknown. Although Fg biosynthesis by megakaryocytes (MK) has been suggested, recent studies have demonstrated that certain alpha-granular proteins originate primarily from plasma. To study the origin of alpha-granule Fg, platelet-associated Fg was measured by ELISA and Western blotting, and localized by immunofluorescence and immunoelectron microscopy in a patient with symptomatic congenital afibrinogenemia before and after replacement therapy with cryoprecipitate. alpha-Granule Fg was detected in the majority of platelets as early as 24 h postinfusion, suggesting that direct platelet uptake was occurring. Platelet Fg reached a maximum value of 42.5% of normal values at 3 d postinfusion and was localized in the alpha-granules, while plasma levels followed a typical half-life profile. Significant alpha-granule Fg was still detectable at 13 d postinfusion, with plasma Fg virtually absent. Studies on cultured CFU-MKs from the patient also confirmed that MKs can incorporate exogeneous Fg into alpha-granules. These results indicate that platelet alpha-granule Fg can be derived from the circulating plasma pool and that Fg uptake can occur in both platelets and MKs.

The London-East Anglia randomized controlled trial of cognitive-behaviour therapy for psychosis. IV: Self-esteem and persecutory delusions.

Abstract: Objectives. There has been a resurgence of interest in the view that persecutory delusions serve a function of defending self-esteem. An alternative account of levels of self-esteem in individuals with persecutory delusions is that they result from processes similar to those studied in people with depression (i.e. from the occurrence of a range of life experiences and how the individual interprets and copes with them). This study aimed to examine both hypotheses together for the first time, and, as the literature indicates that delusions may not share a common cause, attention was given to the possibility of the presence of subgroups.Design. Data were examined cross-sectionally and longitudinally from a randomized controlled trial of cognitive behaviour therapy for 60 people with drug-resistant psychosis.Method. The study is based on the initial assessment of all participants on self-esteem, delusional conviction and a large number of demographic, clinical and cognitive measures. Longitudinal analyses were also carried out, and are reported separately for those who received the therapy intervention and those in the control group.Results. Almost three-quarters of participants with persecutory delusions reported low self-esteem. Changes over time in total self-esteem correlated with changes in measures of mood and social functioning, but not conviction in persecutory delusions. The individuals who initially had normal levels of self-esteem displayed a different pattern of results from the majority of participants.Conclusion. Low self-esteem in people with drug-resistant persecutory delusions is common and, in most cases, can best be understood in terms of normal emotional processes. There was evidence that the majority of persecutory delusions do not fit either strong or weak formulations of the delusion-as-defence explanation and that there may be subgroups with differing aetiologies. These results need to be replicated, and extended to groups in which symptoms are not resistant to medication.

Quantitative “magnetic resonance immunohistochemistry” with ligand‐targeted 19F nanoparticles

Abstract: Unstable atherosclerotic plaques exhibit microdeposits of fibrin that may indicate the potential for a future rupture. However, current methods for evaluating the stage of an atherosclerotic lesion only involve characterizing the level of vessel stenosis, without delineating which lesions are beginning to rupture. Previous work has shown that fibrin-targeted, liquid perfluorocarbon nanoparticles, which carry a high payload of gadolinium, have a high sensitivity and specificity for detecting fibrin with clinical (1)H MRI. In this work, the perfluorocarbon content of the targeted nanoparticles is exploited for the purposes of (19)F imaging and spectroscopy to demonstrate a method for quantifiable molecular imaging of fibrin in vitro at 4.7 T. Additionally, the quantity of bound nanoparticles formulated with different perfluorocarbon species was calculated using spectroscopy. Results indicate that the high degree of nanoparticle binding to fibrin clots and the lack of background (19)F signal allow accurate quantification using spectroscopy at 4.7 T, as corroborated with proton relaxation rate measurements at 1.5 T and trace element (gadolinium) analysis. Finally, the extension of these techniques to a clinically relevant application, the evaluation of the fibrin burden within an ex vivo human carotid endarterectomy sample, demonstrates the potential use of these particles for uniquely identifying unstable atherosclerotic lesions in vivo.