The Stokes boundary layer for a thixotropic or antithixotropic fluid

We present a mathematical investigation of the oscillatory boundary layer (‘Stokes layer’) in a semi-infinite fluid bounded by an oscillating wall (the socalled ‘Stokes problem’), when the fluid has a thixotropic or antithixotropic rheology. We obtain asymptotic solutions in the limit of small-amplitude oscillations, and we use numerical integration to validate the asymptotic solutions and to explore the behaviour of the system for larger-amplitude oscillations. The solutions that we obtain differ significantly from the classical solution for a Newtonian fluid. In particular, for antithixotropic fluids the velocity reaches zero at a finite distance from the wall, in contrast to the exponential decay for a thixotropic or a Newtonian fluid. For small amplitudes of oscillation, three regimes of behaviour are possible: the structure parameter may take values defined instantaneously by the shear rate, or by a long-term average; or it may behave hysteretically. The regime boundaries depend on the precise specification of structure build-up and breakdown rates in the rheological model, illustrating the subtleties of complex fluid models in non-rheometric settings. For larger amplitudes of oscillation the dominant behaviour is hysteretic. We discuss in particular the relationship between the shear stress and the shear rate at the oscillating wall

Are there functional consequences of a reduction in selenium intake in UK subjects?

Dietary Se levels in the UK have fallen over the last 20 years and recent surveys indicate that average Se intakes are 30-40 microg/d, which is well below the current UK reference nutrient intake for adult men (75 microg/d) or women (60 microg/d). Functional consequences of this decline have not been recognised, although epidemiological data suggest it may contribute to increased risk of infections and incidence of some cancers. Previous data have indicated that biochemical changes in Se-dependent proteins occur in otherwise healthy UK subjects given small Se supplements. The current studies have focused on the effect of small Se supplements on the immune response since there is evidence of specific interactions between Se intake and viral replication, and since the potential anti-cancer effects of Se may be mediated by non-antioxidant effects of Se such as changes in immune function. Data indicate that subjects given small Se supplements (50 or 100 microg Se/d) have changes in the activity of Se-dependent enzymes and evidence of improved immune function and clearance of an administered live attenuated virus in the form of poliovirus vaccine. Responses of individual subjects to Se supplements are variable, and current work is evaluating potential explanations for this variability, including genetic variability and pre-existing Se status

A pilot study of megestrol acetate and ibuprofen in the treatment of cachexia in gastrointestinal cancer patients.

Advanced gastrointestinal cancer patients with weight loss and an acute-phase response (n = 15) were given megestrol acetate (480 mg day(-1)) and ibuprofen (1200 mg day(-1)) for 6 weeks. Overall, there was an increase in body weight (P = 0.01) and a reduction in C-reactive protein concentrations (P = 0.02), with no change in total body water (P = 0.24) over this period. This regimen may be an effective non-toxic treatment for cancer cachexia and is worthy of further study

An evaluation of the impact of a multidisciplinary team, in a single centre, on treatment and survival in patients with inoperable non-small-cell lung cancer

Treatment and survival of patients with inoperable Non-small-cell lung cancer in 1997 (n=117) and 2001 (n=126), before and after the introduction of a multidisciplinary team, was examined in a single centre. There were no differences in age, sex and extent of deprivation between the two years. However, in 2001, 23% of patients received chemotherapy treatment compared with 7% in 1997 (P<0.001). Median survival in 2001 was 6.6 months compared with 3.2 months in 1997 (P<0.001)

A common cause for a common phenotype : the gatekeeper hypothesis in fetal programming

Copyright © 2011 Elsevier Ltd. All rights reserved.Peer reviewedPublisher PD

Evaluation of a follow-up programme after curative resection for colorectal cancer

Frequent liver imaging can detect liver metastases from colorectal cancer at an asymptomatic stage. © 1999 Cancer Research Campaig

The relationship between weight loss and interleukin 6 in non-small-cell lung cancer.

Markers of the inflammatory response, interleukin 6, C-reactive protein, albumin and full blood count, were measured in non-small-cell lung cancer (NSCLC) patients (n = 21) with and without weight loss ( > 5%). There were significant increases in circulating C-reactive protein (P < 0.001), interleukin 6 (P < 0.01) and platelets (P < 0.01) in the weight-losing group. Moreover, there was a statistically significant correlation (r = 0.785, P < 0.001) between interleukin 6 and C-reactive protein concentrations. These results are consistent with interleukin 6 and the acute phase response promoting weight loss in NSCLC

Using automated imaging to interrogate gonadotrophin-releasing hormone receptor trafficking and function

Gonadotrophin-releasing hormone (GnRH) acts via seven transmembrane receptors on gonadotrophs to stimulate gonadotrophin synthesis and secretion, and thereby mediates central control of reproduction. Type I mammalian GnRHR are unique, in that they lack C-terminal tails. This is thought to underlie their resistance to rapid homologous desensitisation as well as their slow rate of internalisation and inability to provoke G-protein-independent (arrestin-mediated) signalling. More recently it has been discovered that the vast majority of human GnRHR are actually intracellular, in spite of the fact that they are activated at the cell surface by a membrane impermeant peptide hormone. This apparently reflects inefficient exit from the endoplasmic reticulum and again, the absence of the C-tail likely contributes to their intracellular localisation. This review is intended to cover some of these novel aspects of GnRHR biology, focusing on ways that we have used automated fluorescence microscopy (high content imaging) to explore GnRHR localisation and trafficking as well as spatial and temporal aspects of GnRH signalling via the Ca(2+)/calmodulin/calcineurin/NFAT and Raf/MEK/ERK pathways